SDL 3.0
SDL_stdinc.h File Reference
#include <SDL3/SDL_platform_defines.h>
#include <stdarg.h>
#include <stdint.h>
#include <string.h>
#include <wchar.h>
#include <SDL3/SDL_begin_code.h>
#include <SDL3/SDL_close_code.h>
+ Include dependency graph for SDL_stdinc.h:

Go to the source code of this file.

Macros

#define bool   unsigned char
 
#define false   0
 
#define true   1
 
#define __bool_true_false_are_defined   1
 
#define SDL_SIZE_MAX   ((size_t) -1)
 
#define SDL_COMPILE_TIME_ASSERT(name, x)
 
#define SDL_arraysize(array)
 
#define SDL_STRINGIFY_ARG(arg)
 
Cast operators

Use proper C++ casts when compiled as C++ to be compatible with the option -Wold-style-cast of GCC (and -Werror=old-style-cast in GCC 4.2 and above).

#define SDL_reinterpret_cast(type, expression)
 
#define SDL_static_cast(type, expression)
 
#define SDL_const_cast(type, expression)
 
#define SDL_FOURCC(A, B, C, D)
 
#define SDL_SINT64_C(c)
 
#define SDL_UINT64_C(c)
 

Functions

void * alloca (size_t)
 

Basic data types

#define SDL_MAX_SINT8   ((Sint8)0x7F) /* 127 */
 
#define SDL_MIN_SINT8   ((Sint8)(~0x7F)) /* -128 */
 
#define SDL_MAX_UINT8   ((Uint8)0xFF) /* 255 */
 
#define SDL_MIN_UINT8   ((Uint8)0x00) /* 0 */
 
#define SDL_MAX_SINT16   ((Sint16)0x7FFF) /* 32767 */
 
#define SDL_MIN_SINT16   ((Sint16)(~0x7FFF)) /* -32768 */
 
#define SDL_MAX_UINT16   ((Uint16)0xFFFF) /* 65535 */
 
#define SDL_MIN_UINT16   ((Uint16)0x0000) /* 0 */
 
#define SDL_MAX_SINT32   ((Sint32)0x7FFFFFFF) /* 2147483647 */
 
#define SDL_MIN_SINT32   ((Sint32)(~0x7FFFFFFF)) /* -2147483648 */
 
#define SDL_MAX_UINT32   ((Uint32)0xFFFFFFFFu) /* 4294967295 */
 
#define SDL_MIN_UINT32   ((Uint32)0x00000000) /* 0 */
 
#define SDL_MAX_SINT64   SDL_SINT64_C(0x7FFFFFFFFFFFFFFF) /* 9223372036854775807 */
 
#define SDL_MIN_SINT64   ~SDL_SINT64_C(0x7FFFFFFFFFFFFFFF) /* -9223372036854775808 */
 
#define SDL_MAX_UINT64   SDL_UINT64_C(0xFFFFFFFFFFFFFFFF) /* 18446744073709551615 */
 
#define SDL_MIN_UINT64   SDL_UINT64_C(0x0000000000000000) /* 0 */
 
#define SDL_MAX_TIME   SDL_MAX_SINT64
 
#define SDL_MIN_TIME   SDL_MIN_SINT64
 
typedef int8_t Sint8
 
typedef uint8_t Uint8
 
typedef int16_t Sint16
 
typedef uint16_t Uint16
 
typedef int32_t Sint32
 
typedef uint32_t Uint32
 
typedef int64_t Sint64
 
typedef uint64_t Uint64
 
typedef Sint64 SDL_Time
 

Floating-point constants

#define SDL_FLT_EPSILON   1.1920928955078125e-07F /* 0x0.000002p0 */
 
#define SDL_PRIs64   "lld"
 
#define SDL_PRIu64   "llu"
 
#define SDL_PRIx64   "llx"
 
#define SDL_PRIX64   "llX"
 
#define SDL_PRIs32   "d"
 
#define SDL_PRIu32   "u"
 
#define SDL_PRIx32   "x"
 
#define SDL_PRIX32   "X"
 
#define SDL_PRILL_PREFIX   "ll"
 
#define SDL_PRILLd   SDL_PRILL_PREFIX "d"
 
#define SDL_PRILLu   SDL_PRILL_PREFIX "u"
 
#define SDL_PRILLx   SDL_PRILL_PREFIX "x"
 
#define SDL_PRILLX   SDL_PRILL_PREFIX "X"
 
#define SDL_IN_BYTECAP(x)
 
#define SDL_INOUT_Z_CAP(x)
 
#define SDL_OUT_Z_CAP(x)
 
#define SDL_OUT_CAP(x)
 
#define SDL_OUT_BYTECAP(x)
 
#define SDL_OUT_Z_BYTECAP(x)
 
#define SDL_PRINTF_FORMAT_STRING
 
#define SDL_SCANF_FORMAT_STRING
 
#define SDL_PRINTF_VARARG_FUNC(fmtargnumber)
 
#define SDL_PRINTF_VARARG_FUNCV(fmtargnumber)
 
#define SDL_SCANF_VARARG_FUNC(fmtargnumber)
 
#define SDL_SCANF_VARARG_FUNCV(fmtargnumber)
 
#define SDL_WPRINTF_VARARG_FUNC(fmtargnumber)
 
#define SDL_WPRINTF_VARARG_FUNCV(fmtargnumber)
 
#define SDL_INIT_INTERFACE(iface)
 
#define SDL_stack_alloc(type, count)
 
#define SDL_stack_free(data)
 
#define SDL_min(x, y)
 
#define SDL_max(x, y)
 
#define SDL_clamp(x, a, b)
 
#define SDL_memcpy   memcpy
 
#define SDL_copyp(dst, src)
 
#define SDL_memmove   memmove
 
#define SDL_memset   memset
 
#define SDL_zero(x)
 
#define SDL_zerop(x)
 
#define SDL_zeroa(x)
 
#define SDL_INVALID_UNICODE_CODEPOINT   0xFFFD
 
#define SDL_PI_D   3.141592653589793238462643383279502884
 
#define SDL_PI_F   3.141592653589793238462643383279502884F
 
#define SDL_ICONV_ERROR   (size_t)-1
 
#define SDL_ICONV_E2BIG   (size_t)-2
 
#define SDL_ICONV_EILSEQ   (size_t)-3
 
#define SDL_ICONV_EINVAL   (size_t)-4
 
#define SDL_iconv_utf8_locale(S)
 
#define SDL_iconv_utf8_ucs2(S)
 
#define SDL_iconv_utf8_ucs4(S)
 
#define SDL_iconv_wchar_utf8(S)
 
typedef void *(* SDL_malloc_func) (size_t size)
 
typedef void *(* SDL_calloc_func) (size_t nmemb, size_t size)
 
typedef void *(* SDL_realloc_func) (void *mem, size_t size)
 
typedef void(* SDL_free_func) (void *mem)
 
typedef struct SDL_Environment SDL_Environment
 
typedef int(* SDL_CompareCallback) (const void *a, const void *b)
 
typedef int(* SDL_CompareCallback_r) (void *userdata, const void *a, const void *b)
 
typedef struct SDL_iconv_data_t * SDL_iconv_t
 
typedef void(* SDL_FunctionPointer) (void)
 
SDL_MALLOC size_t size
 
SDL_MALLOC void * SDL_malloc (size_t size)
 
SDL_MALLOC SDL_ALLOC_SIZE2 (1, 2) void *SDL_calloc(size_t nmemb
 
 SDL_ALLOC_SIZE (2) void *SDL_realloc(void *mem
 
void SDL_free (void *mem)
 
void SDL_GetOriginalMemoryFunctions (SDL_malloc_func *malloc_func, SDL_calloc_func *calloc_func, SDL_realloc_func *realloc_func, SDL_free_func *free_func)
 
void SDL_GetMemoryFunctions (SDL_malloc_func *malloc_func, SDL_calloc_func *calloc_func, SDL_realloc_func *realloc_func, SDL_free_func *free_func)
 
bool SDL_SetMemoryFunctions (SDL_malloc_func malloc_func, SDL_calloc_func calloc_func, SDL_realloc_func realloc_func, SDL_free_func free_func)
 
SDL_MALLOC void * SDL_aligned_alloc (size_t alignment, size_t size)
 
void SDL_aligned_free (void *mem)
 
int SDL_GetNumAllocations (void)
 
SDL_EnvironmentSDL_GetEnvironment (void)
 
SDL_EnvironmentSDL_CreateEnvironment (bool populated)
 
const char * SDL_GetEnvironmentVariable (SDL_Environment *env, const char *name)
 
char ** SDL_GetEnvironmentVariables (SDL_Environment *env)
 
bool SDL_SetEnvironmentVariable (SDL_Environment *env, const char *name, const char *value, bool overwrite)
 
bool SDL_UnsetEnvironmentVariable (SDL_Environment *env, const char *name)
 
void SDL_DestroyEnvironment (SDL_Environment *env)
 
const char * SDL_getenv (const char *name)
 
const char * SDL_getenv_unsafe (const char *name)
 
int SDL_setenv_unsafe (const char *name, const char *value, int overwrite)
 
int SDL_unsetenv_unsafe (const char *name)
 
void SDL_qsort (void *base, size_t nmemb, size_t size, SDL_CompareCallback compare)
 
void * SDL_bsearch (const void *key, const void *base, size_t nmemb, size_t size, SDL_CompareCallback compare)
 
void SDL_qsort_r (void *base, size_t nmemb, size_t size, SDL_CompareCallback_r compare, void *userdata)
 
void * SDL_bsearch_r (const void *key, const void *base, size_t nmemb, size_t size, SDL_CompareCallback_r compare, void *userdata)
 
int SDL_abs (int x)
 
int SDL_isalpha (int x)
 
int SDL_isalnum (int x)
 
int SDL_isblank (int x)
 
int SDL_iscntrl (int x)
 
int SDL_isdigit (int x)
 
int SDL_isxdigit (int x)
 
int SDL_ispunct (int x)
 
int SDL_isspace (int x)
 
int SDL_isupper (int x)
 
int SDL_islower (int x)
 
int SDL_isprint (int x)
 
int SDL_isgraph (int x)
 
int SDL_toupper (int x)
 
int SDL_tolower (int x)
 
Uint16 SDL_crc16 (Uint16 crc, const void *data, size_t len)
 
Uint32 SDL_crc32 (Uint32 crc, const void *data, size_t len)
 
Uint32 SDL_murmur3_32 (const void *data, size_t len, Uint32 seed)
 
void * SDL_memcpy (SDL_OUT_BYTECAP(len) void *dst, SDL_IN_BYTECAP(len) const void *src, size_t len)
 
void * SDL_memmove (SDL_OUT_BYTECAP(len) void *dst, SDL_IN_BYTECAP(len) const void *src, size_t len)
 
void * SDL_memset (SDL_OUT_BYTECAP(len) void *dst, int c, size_t len)
 
void * SDL_memset4 (void *dst, Uint32 val, size_t dwords)
 
int SDL_memcmp (const void *s1, const void *s2, size_t len)
 
size_t SDL_wcslen (const wchar_t *wstr)
 
size_t SDL_wcsnlen (const wchar_t *wstr, size_t maxlen)
 
size_t SDL_wcslcpy (SDL_OUT_Z_CAP(maxlen) wchar_t *dst, const wchar_t *src, size_t maxlen)
 
size_t SDL_wcslcat (SDL_INOUT_Z_CAP(maxlen) wchar_t *dst, const wchar_t *src, size_t maxlen)
 
wchar_t * SDL_wcsdup (const wchar_t *wstr)
 
wchar_t * SDL_wcsstr (const wchar_t *haystack, const wchar_t *needle)
 
wchar_t * SDL_wcsnstr (const wchar_t *haystack, const wchar_t *needle, size_t maxlen)
 
int SDL_wcscmp (const wchar_t *str1, const wchar_t *str2)
 
int SDL_wcsncmp (const wchar_t *str1, const wchar_t *str2, size_t maxlen)
 
int SDL_wcscasecmp (const wchar_t *str1, const wchar_t *str2)
 
int SDL_wcsncasecmp (const wchar_t *str1, const wchar_t *str2, size_t maxlen)
 
long SDL_wcstol (const wchar_t *str, wchar_t **endp, int base)
 
size_t SDL_strlen (const char *str)
 
size_t SDL_strnlen (const char *str, size_t maxlen)
 
size_t SDL_strlcpy (SDL_OUT_Z_CAP(maxlen) char *dst, const char *src, size_t maxlen)
 
size_t SDL_utf8strlcpy (SDL_OUT_Z_CAP(dst_bytes) char *dst, const char *src, size_t dst_bytes)
 
size_t SDL_strlcat (SDL_INOUT_Z_CAP(maxlen) char *dst, const char *src, size_t maxlen)
 
SDL_MALLOC char * SDL_strdup (const char *str)
 
SDL_MALLOC char * SDL_strndup (const char *str, size_t maxlen)
 
char * SDL_strrev (char *str)
 
char * SDL_strupr (char *str)
 
char * SDL_strlwr (char *str)
 
char * SDL_strchr (const char *str, int c)
 
char * SDL_strrchr (const char *str, int c)
 
char * SDL_strstr (const char *haystack, const char *needle)
 
char * SDL_strnstr (const char *haystack, const char *needle, size_t maxlen)
 
char * SDL_strcasestr (const char *haystack, const char *needle)
 
char * SDL_strtok_r (char *str, const char *delim, char **saveptr)
 
size_t SDL_utf8strlen (const char *str)
 
size_t SDL_utf8strnlen (const char *str, size_t bytes)
 
char * SDL_itoa (int value, char *str, int radix)
 
char * SDL_uitoa (unsigned int value, char *str, int radix)
 
char * SDL_ltoa (long value, char *str, int radix)
 
char * SDL_ultoa (unsigned long value, char *str, int radix)
 
char * SDL_lltoa (long long value, char *str, int radix)
 
char * SDL_ulltoa (unsigned long long value, char *str, int radix)
 
int SDL_atoi (const char *str)
 
double SDL_atof (const char *str)
 
long SDL_strtol (const char *str, char **endp, int base)
 
unsigned long SDL_strtoul (const char *str, char **endp, int base)
 
long long SDL_strtoll (const char *str, char **endp, int base)
 
unsigned long long SDL_strtoull (const char *str, char **endp, int base)
 
double SDL_strtod (const char *str, char **endp)
 
int SDL_strcmp (const char *str1, const char *str2)
 
int SDL_strncmp (const char *str1, const char *str2, size_t maxlen)
 
int SDL_strcasecmp (const char *str1, const char *str2)
 
int SDL_strncasecmp (const char *str1, const char *str2, size_t maxlen)
 
char * SDL_strpbrk (const char *str, const char *breakset)
 
Uint32 SDL_StepUTF8 (const char **pstr, size_t *pslen)
 
Uint32 SDL_StepBackUTF8 (const char *start, const char **pstr)
 
char * SDL_UCS4ToUTF8 (Uint32 codepoint, char *dst)
 
int SDL_sscanf (const char *text, SDL_SCANF_FORMAT_STRING const char *fmt,...) SDL_SCANF_VARARG_FUNC(2)
 
int SDL_vsscanf (const char *text, SDL_SCANF_FORMAT_STRING const char *fmt, va_list ap) SDL_SCANF_VARARG_FUNCV(2)
 
int SDL_snprintf (SDL_OUT_Z_CAP(maxlen) char *text, size_t maxlen, SDL_PRINTF_FORMAT_STRING const char *fmt,...) SDL_PRINTF_VARARG_FUNC(3)
 
int SDL_swprintf (SDL_OUT_Z_CAP(maxlen) wchar_t *text, size_t maxlen, SDL_PRINTF_FORMAT_STRING const wchar_t *fmt,...) SDL_WPRINTF_VARARG_FUNC(3)
 
int SDL_vsnprintf (SDL_OUT_Z_CAP(maxlen) char *text, size_t maxlen, SDL_PRINTF_FORMAT_STRING const char *fmt, va_list ap) SDL_PRINTF_VARARG_FUNCV(3)
 
int SDL_vswprintf (SDL_OUT_Z_CAP(maxlen) wchar_t *text, size_t maxlen, SDL_PRINTF_FORMAT_STRING const wchar_t *fmt, va_list ap) SDL_WPRINTF_VARARG_FUNCV(3)
 
int SDL_asprintf (char **strp, SDL_PRINTF_FORMAT_STRING const char *fmt,...) SDL_PRINTF_VARARG_FUNC(2)
 
int SDL_vasprintf (char **strp, SDL_PRINTF_FORMAT_STRING const char *fmt, va_list ap) SDL_PRINTF_VARARG_FUNCV(2)
 
void SDL_srand (Uint64 seed)
 
Sint32 SDL_rand (Sint32 n)
 
float SDL_randf (void)
 
Uint32 SDL_rand_bits (void)
 
Sint32 SDL_rand_r (Uint64 *state, Sint32 n)
 
float SDL_randf_r (Uint64 *state)
 
Uint32 SDL_rand_bits_r (Uint64 *state)
 
double SDL_acos (double x)
 
float SDL_acosf (float x)
 
double SDL_asin (double x)
 
float SDL_asinf (float x)
 
double SDL_atan (double x)
 
float SDL_atanf (float x)
 
double SDL_atan2 (double y, double x)
 
float SDL_atan2f (float y, float x)
 
double SDL_ceil (double x)
 
float SDL_ceilf (float x)
 
double SDL_copysign (double x, double y)
 
float SDL_copysignf (float x, float y)
 
double SDL_cos (double x)
 
float SDL_cosf (float x)
 
double SDL_exp (double x)
 
float SDL_expf (float x)
 
double SDL_fabs (double x)
 
float SDL_fabsf (float x)
 
double SDL_floor (double x)
 
float SDL_floorf (float x)
 
double SDL_trunc (double x)
 
float SDL_truncf (float x)
 
double SDL_fmod (double x, double y)
 
float SDL_fmodf (float x, float y)
 
int SDL_isinf (double x)
 
int SDL_isinff (float x)
 
int SDL_isnan (double x)
 
int SDL_isnanf (float x)
 
double SDL_log (double x)
 
float SDL_logf (float x)
 
double SDL_log10 (double x)
 
float SDL_log10f (float x)
 
double SDL_modf (double x, double *y)
 
float SDL_modff (float x, float *y)
 
double SDL_pow (double x, double y)
 
float SDL_powf (float x, float y)
 
double SDL_round (double x)
 
float SDL_roundf (float x)
 
long SDL_lround (double x)
 
long SDL_lroundf (float x)
 
double SDL_scalbn (double x, int n)
 
float SDL_scalbnf (float x, int n)
 
double SDL_sin (double x)
 
float SDL_sinf (float x)
 
double SDL_sqrt (double x)
 
float SDL_sqrtf (float x)
 
double SDL_tan (double x)
 
float SDL_tanf (float x)
 
SDL_iconv_t SDL_iconv_open (const char *tocode, const char *fromcode)
 
int SDL_iconv_close (SDL_iconv_t cd)
 
size_t SDL_iconv (SDL_iconv_t cd, const char **inbuf, size_t *inbytesleft, char **outbuf, size_t *outbytesleft)
 
char * SDL_iconv_string (const char *tocode, const char *fromcode, const char *inbuf, size_t inbytesleft)
 
SDL_FORCE_INLINE bool SDL_size_mul_check_overflow (size_t a, size_t b, size_t *ret)
 
SDL_FORCE_INLINE bool SDL_size_add_check_overflow (size_t a, size_t b, size_t *ret)
 

Macro Definition Documentation

◆ __bool_true_false_are_defined

#define __bool_true_false_are_defined   1

Definition at line 75 of file SDL_stdinc.h.

◆ bool

#define bool   unsigned char

CategoryStdinc

SDL provides its own implementation of some of the most important C runtime functions.

Using these functions allows an app to have access to common C functionality without depending on a specific C runtime (or a C runtime at all). More importantly, the SDL implementations work identically across platforms, so apps can avoid surprises like snprintf() behaving differently between Windows and Linux builds, or itoa() only existing on some platforms.

For many of the most common functions, like SDL_memcpy, SDL might just call through to the usual C runtime behind the scenes, if it makes sense to do so (if it's faster and always available/reliable on a given platform), reducing library size and offering the most optimized option.

SDL also offers other C-runtime-adjacent functionality in this header that either isn't, strictly speaking, part of any C runtime standards, like SDL_crc32() and SDL_reinterpret_cast, etc. It also offers a few better options, like SDL_strlcpy(), which functions as a safer form of strcpy().

Definition at line 72 of file SDL_stdinc.h.

◆ false

#define false   0

Definition at line 73 of file SDL_stdinc.h.

◆ SDL_arraysize

#define SDL_arraysize ( array)
Value:
(sizeof(array)/sizeof(array[0]))

The number of elements in a static array.

This will compile but return incorrect results for a pointer to an array; it has to be an array the compiler knows the size of.

This macro looks like it double-evaluates the argument, but it does so inside of sizeof, so there are no side-effects here, as expressions do not actually run any code in these cases.

Since
This macro is available since SDL 3.2.0.

Definition at line 225 of file SDL_stdinc.h.

◆ SDL_clamp

#define SDL_clamp ( x,
a,
b )
Value:
(((x) < (a)) ? (a) : (((x) > (b)) ? (b) : (x)))

Return a value clamped to a range.

If x is outside the range a values between a and b, the returned value will be a or b as appropriate. Otherwise, x is returned.

This macro will produce incorrect results if b is less than a.

This is a helper macro that might be more clear than writing out the comparisons directly, and works with any type that can be compared with the < and > operators. However, it double-evaluates all its parameters, so do not use expressions with side-effects here.

Parameters
xthe value to compare.
athe low end value.
bthe high end value.
Returns
x, clamped between a and b.

\threadsafety It is safe to call this macro from any thread.

Since
This macro is available since SDL 3.2.0.

Definition at line 2140 of file SDL_stdinc.h.

◆ SDL_COMPILE_TIME_ASSERT

#define SDL_COMPILE_TIME_ASSERT ( name,
x )
Value:
typedef int SDL_compile_time_assert_ ## name[(x) * 2 - 1]

Definition at line 209 of file SDL_stdinc.h.

209#define SDL_COMPILE_TIME_ASSERT(name, x) \
210 typedef int SDL_compile_time_assert_ ## name[(x) * 2 - 1]

◆ SDL_const_cast

#define SDL_const_cast ( type,
expression )
Value:
((type)(expression))

Definition at line 325 of file SDL_stdinc.h.

◆ SDL_copyp

#define SDL_copyp ( dst,
src )
Value:
{ SDL_COMPILE_TIME_ASSERT(SDL_copyp, sizeof (*(dst)) == sizeof (*(src))); } \
SDL_memcpy((dst), (src), sizeof(*(src)))
#define SDL_copyp(dst, src)
#define SDL_COMPILE_TIME_ASSERT(name, x)
Definition SDL_stdinc.h:209

A macro to copy memory between objects, with basic type checking.

SDL_memcpy and SDL_memmove do not care where you copy memory to and from, which can lead to bugs. This macro aims to avoid most of those bugs by making sure that the source and destination are both pointers to objects that are the same size. It does not check that the objects are the same type, just that the copy will not overflow either object.

The size check happens at compile time, and the compiler will throw an error if the objects are different sizes.

Generally this is intended to copy a single object, not an array.

This macro looks like it double-evaluates its parameters, but the extras them are in sizeof sections, which generate no code nor side-effects.

Parameters
dsta pointer to the destination object. Must not be NULL.
srca pointer to the source object. Must not be NULL.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

Definition at line 2499 of file SDL_stdinc.h.

2499#define SDL_copyp(dst, src) \
2500 { SDL_COMPILE_TIME_ASSERT(SDL_copyp, sizeof (*(dst)) == sizeof (*(src))); } \
2501 SDL_memcpy((dst), (src), sizeof(*(src)))

◆ SDL_FLT_EPSILON

#define SDL_FLT_EPSILON   1.1920928955078125e-07F /* 0x0.000002p0 */

Epsilon constant, used for comparing floating-point numbers.

Equals by default to platform-defined FLT_EPSILON, or 1.1920928955078125e-07F if that's not available.

Since
This macro is available since SDL 3.2.0.

Definition at line 523 of file SDL_stdinc.h.

Referenced by SDL_RectsEqualFloat().

◆ SDL_FOURCC

#define SDL_FOURCC ( A,
B,
C,
D )
Value:
uint8_t Uint8
Definition SDL_stdinc.h:425
#define SDL_static_cast(type, expression)
Definition SDL_stdinc.h:324
uint32_t Uint32
Definition SDL_stdinc.h:461

Define a four character code as a Uint32.

Parameters
Athe first ASCII character.
Bthe second ASCII character.
Cthe third ASCII character.
Dthe fourth ASCII character.
Returns
the four characters converted into a Uint32, one character per-byte.

\threadsafety It is safe to call this macro from any thread.

Since
This macro is available since SDL 3.2.0.

Definition at line 344 of file SDL_stdinc.h.

344#define SDL_FOURCC(A, B, C, D) \
345 ((SDL_static_cast(Uint32, SDL_static_cast(Uint8, (A))) << 0) | \
346 (SDL_static_cast(Uint32, SDL_static_cast(Uint8, (B))) << 8) | \
347 (SDL_static_cast(Uint32, SDL_static_cast(Uint8, (C))) << 16) | \
348 (SDL_static_cast(Uint32, SDL_static_cast(Uint8, (D))) << 24))

◆ SDL_ICONV_E2BIG

#define SDL_ICONV_E2BIG   (size_t)-2

Output buffer was too small.

Definition at line 5849 of file SDL_stdinc.h.

◆ SDL_ICONV_EILSEQ

#define SDL_ICONV_EILSEQ   (size_t)-3

Invalid input sequence was encountered.

Definition at line 5850 of file SDL_stdinc.h.

◆ SDL_ICONV_EINVAL

#define SDL_ICONV_EINVAL   (size_t)-4

Incomplete input sequence was encountered.

Definition at line 5851 of file SDL_stdinc.h.

◆ SDL_ICONV_ERROR

#define SDL_ICONV_ERROR   (size_t)-1

Generic error. Check SDL_GetError()?

Definition at line 5848 of file SDL_stdinc.h.

◆ SDL_iconv_utf8_locale

#define SDL_iconv_utf8_locale ( S)
Value:
SDL_iconv_string("", "UTF-8", S, SDL_strlen(S)+1)
char * SDL_iconv_string(const char *tocode, const char *fromcode, const char *inbuf, size_t inbytesleft)
size_t SDL_strlen(const char *str)

Convert a UTF-8 string to the current locale's character encoding.

This is a helper macro that might be more clear than calling SDL_iconv_string directly. However, it double-evaluates its parameter, so do not use an expression with side-effects here.

Parameters
Sthe string to convert.
Returns
a new string, converted to the new encoding, or NULL on error.
Since
This macro is available since SDL 3.2.0.

Definition at line 5898 of file SDL_stdinc.h.

◆ SDL_iconv_utf8_ucs2

#define SDL_iconv_utf8_ucs2 ( S)
Value:
(Uint16 *)SDL_iconv_string("UCS-2", "UTF-8", S, SDL_strlen(S)+1)
uint16_t Uint16
Definition SDL_stdinc.h:443

Convert a UTF-8 string to UCS-2.

This is a helper macro that might be more clear than calling SDL_iconv_string directly. However, it double-evaluates its parameter, so do not use an expression with side-effects here.

Parameters
Sthe string to convert.
Returns
a new string, converted to the new encoding, or NULL on error.
Since
This macro is available since SDL 3.2.0.

Definition at line 5912 of file SDL_stdinc.h.

◆ SDL_iconv_utf8_ucs4

#define SDL_iconv_utf8_ucs4 ( S)
Value:
(Uint32 *)SDL_iconv_string("UCS-4", "UTF-8", S, SDL_strlen(S)+1)

Convert a UTF-8 string to UCS-4.

This is a helper macro that might be more clear than calling SDL_iconv_string directly. However, it double-evaluates its parameter, so do not use an expression with side-effects here.

Parameters
Sthe string to convert.
Returns
a new string, converted to the new encoding, or NULL on error.
Since
This macro is available since SDL 3.2.0.

Definition at line 5926 of file SDL_stdinc.h.

◆ SDL_iconv_wchar_utf8

#define SDL_iconv_wchar_utf8 ( S)
Value:
SDL_iconv_string("UTF-8", "WCHAR_T", (char *)S, (SDL_wcslen(S)+1)*sizeof(wchar_t))
size_t SDL_wcslen(const wchar_t *wstr)

Convert a wchar_t string to UTF-8.

This is a helper macro that might be more clear than calling SDL_iconv_string directly. However, it double-evaluates its parameter, so do not use an expression with side-effects here.

Parameters
Sthe string to convert.
Returns
a new string, converted to the new encoding, or NULL on error.
Since
This macro is available since SDL 3.2.0.

Definition at line 5940 of file SDL_stdinc.h.

◆ SDL_IN_BYTECAP

#define SDL_IN_BYTECAP ( x)

Definition at line 1120 of file SDL_stdinc.h.

◆ SDL_INIT_INTERFACE

#define SDL_INIT_INTERFACE ( iface)
Value:
do { \
SDL_zerop(iface); \
(iface)->version = sizeof(*(iface)); \
} while (0)

A macro to initialize an SDL interface.

This macro will initialize an SDL interface structure and should be called before you fill out the fields with your implementation.

You can use it like this:

// Fill in the interface function pointers with your implementation
iface.seek = ...
stream = SDL_OpenIO(&iface, NULL);
#define NULL
SDL_IOStream * SDL_OpenIO(const SDL_IOStreamInterface *iface, void *userdata)
#define SDL_INIT_INTERFACE(iface)
Sint64(* seek)(void *userdata, Sint64 offset, SDL_IOWhence whence)

If you are using designated initializers, you can use the size of the interface as the version, e.g.

.version = sizeof(iface),
.seek = ...
};
stream = SDL_OpenIO(&iface, NULL);

\threadsafety It is safe to call this macro from any thread.

Since
This macro is available since SDL 3.2.0.
See also
SDL_IOStreamInterface
SDL_StorageInterface
SDL_VirtualJoystickDesc

Definition at line 1235 of file SDL_stdinc.h.

1235#define SDL_INIT_INTERFACE(iface) \
1236 do { \
1237 SDL_zerop(iface); \
1238 (iface)->version = sizeof(*(iface)); \
1239 } while (0)

◆ SDL_INOUT_Z_CAP

#define SDL_INOUT_Z_CAP ( x)

Definition at line 1121 of file SDL_stdinc.h.

◆ SDL_INVALID_UNICODE_CODEPOINT

#define SDL_INVALID_UNICODE_CODEPOINT   0xFFFD

The Unicode REPLACEMENT CHARACTER codepoint.

SDL_StepUTF8() and SDL_StepBackUTF8() report this codepoint when they encounter a UTF-8 string with encoding errors.

This tends to render as something like a question mark in most places.

Since
This macro is available since SDL 3.2.0.
See also
SDL_StepBackUTF8
SDL_StepUTF8

Definition at line 3944 of file SDL_stdinc.h.

◆ SDL_max

#define SDL_max ( x,
y )
Value:
(((x) > (y)) ? (x) : (y))

Return the greater of two values.

This is a helper macro that might be more clear than writing out the comparisons directly, and works with any type that can be compared with the > operator. However, it double-evaluates both its parameters, so do not use expressions with side-effects here.

Parameters
xthe first value to compare.
ythe second value to compare.
Returns
the lesser of x and y.

\threadsafety It is safe to call this macro from any thread.

Since
This macro is available since SDL 3.2.0.

Definition at line 2116 of file SDL_stdinc.h.

◆ SDL_MAX_SINT16

#define SDL_MAX_SINT16   ((Sint16)0x7FFF) /* 32767 */

Definition at line 435 of file SDL_stdinc.h.

◆ SDL_MAX_SINT32

#define SDL_MAX_SINT32   ((Sint32)0x7FFFFFFF) /* 2147483647 */

Definition at line 453 of file SDL_stdinc.h.

◆ SDL_MAX_SINT64

#define SDL_MAX_SINT64   SDL_SINT64_C(0x7FFFFFFFFFFFFFFF) /* 9223372036854775807 */

Definition at line 473 of file SDL_stdinc.h.

◆ SDL_MAX_SINT8

#define SDL_MAX_SINT8   ((Sint8)0x7F) /* 127 */

Definition at line 417 of file SDL_stdinc.h.

◆ SDL_MAX_TIME

#define SDL_MAX_TIME   SDL_MAX_SINT64

Definition at line 501 of file SDL_stdinc.h.

◆ SDL_MAX_UINT16

#define SDL_MAX_UINT16   ((Uint16)0xFFFF) /* 65535 */

Definition at line 444 of file SDL_stdinc.h.

◆ SDL_MAX_UINT32

#define SDL_MAX_UINT32   ((Uint32)0xFFFFFFFFu) /* 4294967295 */

Definition at line 462 of file SDL_stdinc.h.

◆ SDL_MAX_UINT64

#define SDL_MAX_UINT64   SDL_UINT64_C(0xFFFFFFFFFFFFFFFF) /* 18446744073709551615 */

Definition at line 484 of file SDL_stdinc.h.

◆ SDL_MAX_UINT8

#define SDL_MAX_UINT8   ((Uint8)0xFF) /* 255 */

Definition at line 426 of file SDL_stdinc.h.

◆ SDL_memcpy

#define SDL_memcpy   memcpy

Definition at line 2471 of file SDL_stdinc.h.

◆ SDL_memmove

#define SDL_memmove   memmove

Definition at line 2527 of file SDL_stdinc.h.

◆ SDL_memset

#define SDL_memset   memset

Definition at line 2575 of file SDL_stdinc.h.

◆ SDL_min

#define SDL_min ( x,
y )
Value:
(((x) < (y)) ? (x) : (y))

Return the lesser of two values.

This is a helper macro that might be more clear than writing out the comparisons directly, and works with any type that can be compared with the < operator. However, it double-evaluates both its parameters, so do not use expressions with side-effects here.

Parameters
xthe first value to compare.
ythe second value to compare.
Returns
the lesser of x and y.

\threadsafety It is safe to call this macro from any thread.

Since
This macro is available since SDL 3.2.0.

Definition at line 2098 of file SDL_stdinc.h.

◆ SDL_MIN_SINT16

#define SDL_MIN_SINT16   ((Sint16)(~0x7FFF)) /* -32768 */

Definition at line 436 of file SDL_stdinc.h.

◆ SDL_MIN_SINT32

#define SDL_MIN_SINT32   ((Sint32)(~0x7FFFFFFF)) /* -2147483648 */

Definition at line 454 of file SDL_stdinc.h.

◆ SDL_MIN_SINT64

#define SDL_MIN_SINT64   ~SDL_SINT64_C(0x7FFFFFFFFFFFFFFF) /* -9223372036854775808 */

Definition at line 474 of file SDL_stdinc.h.

◆ SDL_MIN_SINT8

#define SDL_MIN_SINT8   ((Sint8)(~0x7F)) /* -128 */

Definition at line 418 of file SDL_stdinc.h.

◆ SDL_MIN_TIME

#define SDL_MIN_TIME   SDL_MIN_SINT64

Definition at line 502 of file SDL_stdinc.h.

◆ SDL_MIN_UINT16

#define SDL_MIN_UINT16   ((Uint16)0x0000) /* 0 */

Definition at line 445 of file SDL_stdinc.h.

◆ SDL_MIN_UINT32

#define SDL_MIN_UINT32   ((Uint32)0x00000000) /* 0 */

Definition at line 463 of file SDL_stdinc.h.

◆ SDL_MIN_UINT64

#define SDL_MIN_UINT64   SDL_UINT64_C(0x0000000000000000) /* 0 */

Definition at line 485 of file SDL_stdinc.h.

◆ SDL_MIN_UINT8

#define SDL_MIN_UINT8   ((Uint8)0x00) /* 0 */

Definition at line 427 of file SDL_stdinc.h.

◆ SDL_OUT_BYTECAP

#define SDL_OUT_BYTECAP ( x)

Definition at line 1124 of file SDL_stdinc.h.

◆ SDL_OUT_CAP

#define SDL_OUT_CAP ( x)

Definition at line 1123 of file SDL_stdinc.h.

◆ SDL_OUT_Z_BYTECAP

#define SDL_OUT_Z_BYTECAP ( x)

Definition at line 1125 of file SDL_stdinc.h.

◆ SDL_OUT_Z_CAP

#define SDL_OUT_Z_CAP ( x)

Definition at line 1122 of file SDL_stdinc.h.

◆ SDL_PI_D

#define SDL_PI_D   3.141592653589793238462643383279502884

The value of Pi, as a double-precision floating point literal.

Since
This macro is available since SDL 3.2.0.
See also
SDL_PI_F pi (double)

Definition at line 4439 of file SDL_stdinc.h.

◆ SDL_PI_F

#define SDL_PI_F   3.141592653589793238462643383279502884F

The value of Pi, as a single-precision floating point literal.

Since
This macro is available since SDL 3.2.0.
See also
SDL_PI_D pi (float)

Definition at line 4451 of file SDL_stdinc.h.

◆ SDL_PRILL_PREFIX

#define SDL_PRILL_PREFIX   "ll"

Definition at line 787 of file SDL_stdinc.h.

◆ SDL_PRILLd

#define SDL_PRILLd   SDL_PRILL_PREFIX "d"

Definition at line 790 of file SDL_stdinc.h.

◆ SDL_PRILLu

#define SDL_PRILLu   SDL_PRILL_PREFIX "u"

Definition at line 793 of file SDL_stdinc.h.

◆ SDL_PRILLX

#define SDL_PRILLX   SDL_PRILL_PREFIX "X"

Definition at line 799 of file SDL_stdinc.h.

◆ SDL_PRILLx

#define SDL_PRILLx   SDL_PRILL_PREFIX "x"

Definition at line 796 of file SDL_stdinc.h.

◆ SDL_PRINTF_FORMAT_STRING

#define SDL_PRINTF_FORMAT_STRING

Definition at line 1126 of file SDL_stdinc.h.

◆ SDL_PRINTF_VARARG_FUNC

#define SDL_PRINTF_VARARG_FUNC ( fmtargnumber)

Definition at line 1137 of file SDL_stdinc.h.

◆ SDL_PRINTF_VARARG_FUNCV

#define SDL_PRINTF_VARARG_FUNCV ( fmtargnumber)

Definition at line 1138 of file SDL_stdinc.h.

◆ SDL_PRIs32

#define SDL_PRIs32   "d"

Definition at line 756 of file SDL_stdinc.h.

◆ SDL_PRIs64

#define SDL_PRIs64   "lld"

Definition at line 716 of file SDL_stdinc.h.

◆ SDL_PRIu32

#define SDL_PRIu32   "u"

Definition at line 763 of file SDL_stdinc.h.

◆ SDL_PRIu64

#define SDL_PRIu64   "llu"

Definition at line 727 of file SDL_stdinc.h.

◆ SDL_PRIX32

#define SDL_PRIX32   "X"

Definition at line 777 of file SDL_stdinc.h.

◆ SDL_PRIx32

#define SDL_PRIx32   "x"

Definition at line 770 of file SDL_stdinc.h.

◆ SDL_PRIX64

#define SDL_PRIX64   "llX"

Definition at line 749 of file SDL_stdinc.h.

◆ SDL_PRIx64

#define SDL_PRIx64   "llx"

Definition at line 738 of file SDL_stdinc.h.

◆ SDL_reinterpret_cast

#define SDL_reinterpret_cast ( type,
expression )
Value:
((type)(expression))

Definition at line 323 of file SDL_stdinc.h.

◆ SDL_SCANF_FORMAT_STRING

#define SDL_SCANF_FORMAT_STRING

Definition at line 1127 of file SDL_stdinc.h.

◆ SDL_SCANF_VARARG_FUNC

#define SDL_SCANF_VARARG_FUNC ( fmtargnumber)

Definition at line 1139 of file SDL_stdinc.h.

◆ SDL_SCANF_VARARG_FUNCV

#define SDL_SCANF_VARARG_FUNCV ( fmtargnumber)

Definition at line 1140 of file SDL_stdinc.h.

◆ SDL_SINT64_C

#define SDL_SINT64_C ( c)
Value:
c ## LL

Definition at line 388 of file SDL_stdinc.h.

◆ SDL_SIZE_MAX

#define SDL_SIZE_MAX   ((size_t) -1)

Definition at line 157 of file SDL_stdinc.h.

Referenced by SDL_size_add_check_overflow(), and SDL_size_mul_check_overflow().

◆ SDL_stack_alloc

#define SDL_stack_alloc ( type,
count )
Value:
(type*)alloca(sizeof(type)*(count))
void * alloca(size_t)

Definition at line 1287 of file SDL_stdinc.h.

◆ SDL_stack_free

#define SDL_stack_free ( data)

Definition at line 1288 of file SDL_stdinc.h.

◆ SDL_static_cast

#define SDL_static_cast ( type,
expression )
Value:
((type)(expression))

Definition at line 324 of file SDL_stdinc.h.

Referenced by SDL_Swap16(), SDL_Swap32(), and SDL_Swap64().

◆ SDL_STRINGIFY_ARG

#define SDL_STRINGIFY_ARG ( arg)
Value:
#arg

Macro useful for building other macros with strings in them.

For example:

#define LOG_ERROR(X) OutputDebugString(SDL_STRINGIFY_ARG(__FUNCTION__) ": " X "\n")`
Parameters
argthe text to turn into a string literal.
Since
This macro is available since SDL 3.2.0.

Definition at line 240 of file SDL_stdinc.h.

◆ SDL_UINT64_C

#define SDL_UINT64_C ( c)
Value:
c ## ULL

Definition at line 400 of file SDL_stdinc.h.

◆ SDL_WPRINTF_VARARG_FUNC

#define SDL_WPRINTF_VARARG_FUNC ( fmtargnumber)

Definition at line 1141 of file SDL_stdinc.h.

◆ SDL_WPRINTF_VARARG_FUNCV

#define SDL_WPRINTF_VARARG_FUNCV ( fmtargnumber)

Definition at line 1142 of file SDL_stdinc.h.

◆ SDL_zero

#define SDL_zero ( x)
Value:
SDL_memset(&(x), 0, sizeof((x)))
#define SDL_memset

Clear an object's memory to zero.

This is wrapper over SDL_memset that handles calculating the object size, so there's no chance of copy/paste errors, and the code is cleaner.

This requires an object, not a pointer to an object, nor an array.

Parameters
xthe object to clear.

\threadsafety It is safe to call this macro from any thread.

Since
This macro is available since SDL 3.2.0.
See also
SDL_zerop
SDL_zeroa

Definition at line 2595 of file SDL_stdinc.h.

◆ SDL_zeroa

#define SDL_zeroa ( x)
Value:
SDL_memset((x), 0, sizeof((x)))

Clear an array's memory to zero.

This is wrapper over SDL_memset that handles calculating the array size, so there's no chance of copy/paste errors, and the code is cleaner.

This requires an array, not an object, nor a pointer to an object.

Parameters
xan array to clear.

\threadsafety It is safe to call this macro from any thread.

Since
This macro is available since SDL 3.2.0.
See also
SDL_zero
SDL_zeroa

Definition at line 2633 of file SDL_stdinc.h.

◆ SDL_zerop

#define SDL_zerop ( x)
Value:
SDL_memset((x), 0, sizeof(*(x)))

Clear an object's memory to zero, using a pointer.

This is wrapper over SDL_memset that handles calculating the object size, so there's no chance of copy/paste errors, and the code is cleaner.

This requires a pointer to an object, not an object itself, nor an array.

Parameters
xa pointer to the object to clear.

\threadsafety It is safe to call this macro from any thread.

Since
This macro is available since SDL 3.2.0.
See also
SDL_zero
SDL_zeroa

Definition at line 2614 of file SDL_stdinc.h.

◆ true

Typedef Documentation

◆ SDL_calloc_func

typedef void *(* SDL_calloc_func) (size_t nmemb, size_t size)

A callback used to implement SDL_calloc().

SDL will always ensure that the passed nmemb and size are both greater than 0.

Parameters
nmembthe number of elements in the array.
sizethe size of each element of the array.
Returns
a pointer to the allocated array, or NULL if allocation failed.

\threadsafety It should be safe to call this callback from any thread.

Since
This datatype is available since SDL 3.2.0.
See also
SDL_calloc
SDL_GetOriginalMemoryFunctions
SDL_GetMemoryFunctions
SDL_SetMemoryFunctions

Definition at line 1433 of file SDL_stdinc.h.

◆ SDL_CompareCallback

typedef int(* SDL_CompareCallback) (const void *a, const void *b)

A callback used with SDL sorting and binary search functions.

Parameters
aa pointer to the first element being compared.
ba pointer to the second element being compared.
Returns
-1 if a should be sorted before b, 1 if b should be sorted before a, 0 if they are equal. If two elements are equal, their order in the sorted array is undefined.
Since
This callback is available since SDL 3.2.0.
See also
SDL_bsearch
SDL_qsort

Definition at line 1844 of file SDL_stdinc.h.

◆ SDL_CompareCallback_r

typedef int(* SDL_CompareCallback_r) (void *userdata, const void *a, const void *b)

A callback used with SDL sorting and binary search functions.

Parameters
userdatathe userdata pointer passed to the sort function.
aa pointer to the first element being compared.
ba pointer to the second element being compared.
Returns
-1 if a should be sorted before b, 1 if b should be sorted before a, 0 if they are equal. If two elements are equal, their order in the sorted array is undefined.
Since
This callback is available since SDL 3.2.0.
See also
SDL_qsort_r
SDL_bsearch_r

Definition at line 1957 of file SDL_stdinc.h.

◆ SDL_Environment

A thread-safe set of environment variables

Since
This struct is available since SDL 3.2.0.
See also
SDL_GetEnvironment
SDL_CreateEnvironment
SDL_GetEnvironmentVariable
SDL_GetEnvironmentVariables
SDL_SetEnvironmentVariable
SDL_UnsetEnvironmentVariable
SDL_DestroyEnvironment

Definition at line 1616 of file SDL_stdinc.h.

◆ SDL_free_func

typedef void(* SDL_free_func) (void *mem)

A callback used to implement SDL_free().

SDL will always ensure that the passed mem is a non-NULL pointer.

Parameters
mema pointer to allocated memory.

\threadsafety It should be safe to call this callback from any thread.

Since
This datatype is available since SDL 3.2.0.
See also
SDL_free
SDL_GetOriginalMemoryFunctions
SDL_GetMemoryFunctions
SDL_SetMemoryFunctions

Definition at line 1472 of file SDL_stdinc.h.

◆ SDL_FunctionPointer

typedef void(* SDL_FunctionPointer) (void)

Definition at line 6112 of file SDL_stdinc.h.

◆ SDL_iconv_t

typedef struct SDL_iconv_data_t* SDL_iconv_t

An opaque handle representing string encoding conversion state.

Since
This datatype is available since SDL 3.2.0.
See also
SDL_iconv_open

Definition at line 5774 of file SDL_stdinc.h.

◆ SDL_malloc_func

typedef void *(* SDL_malloc_func) (size_t size)

A callback used to implement SDL_malloc().

SDL will always ensure that the passed size is greater than 0.

Parameters
sizethe size to allocate.
Returns
a pointer to the allocated memory, or NULL if allocation failed.

\threadsafety It should be safe to call this callback from any thread.

Since
This datatype is available since SDL 3.2.0.
See also
SDL_malloc
SDL_GetOriginalMemoryFunctions
SDL_GetMemoryFunctions
SDL_SetMemoryFunctions

Definition at line 1412 of file SDL_stdinc.h.

◆ SDL_realloc_func

typedef void *(* SDL_realloc_func) (void *mem, size_t size)

A callback used to implement SDL_realloc().

SDL will always ensure that the passed size is greater than 0.

Parameters
mema pointer to allocated memory to reallocate, or NULL.
sizethe new size of the memory.
Returns
a pointer to the newly allocated memory, or NULL if allocation failed.

\threadsafety It should be safe to call this callback from any thread.

Since
This datatype is available since SDL 3.2.0.
See also
SDL_realloc
SDL_GetOriginalMemoryFunctions
SDL_GetMemoryFunctions
SDL_SetMemoryFunctions

Definition at line 1454 of file SDL_stdinc.h.

◆ SDL_Time

typedef Sint64 SDL_Time

SDL times are signed, 64-bit integers representing nanoseconds since the Unix epoch (Jan 1, 1970).

They can be converted between POSIX time_t values with SDL_NS_TO_SECONDS() and SDL_SECONDS_TO_NS(), and between Windows FILETIME values with SDL_TimeToWindows() and SDL_TimeFromWindows().

Since
This macro is available since SDL 3.2.0.
See also
SDL_MAX_SINT64
SDL_MIN_SINT64

Definition at line 500 of file SDL_stdinc.h.

◆ Sint16

typedef int16_t Sint16

A signed 16-bit integer type.

Since
This macro is available since SDL 3.2.0.

Definition at line 434 of file SDL_stdinc.h.

◆ Sint32

typedef int32_t Sint32

A signed 32-bit integer type.

Since
This macro is available since SDL 3.2.0.

Definition at line 452 of file SDL_stdinc.h.

◆ Sint64

typedef int64_t Sint64

A signed 64-bit integer type.

Since
This macro is available since SDL 3.2.0.
See also
SDL_SINT64_C

Definition at line 472 of file SDL_stdinc.h.

◆ Sint8

typedef int8_t Sint8

A signed 8-bit integer type.

Since
This macro is available since SDL 3.2.0.

Definition at line 416 of file SDL_stdinc.h.

◆ Uint16

typedef uint16_t Uint16

An unsigned 16-bit integer type.

Since
This macro is available since SDL 3.2.0.

Definition at line 443 of file SDL_stdinc.h.

◆ Uint32

typedef uint32_t Uint32

An unsigned 32-bit integer type.

Since
This macro is available since SDL 3.2.0.

Definition at line 461 of file SDL_stdinc.h.

◆ Uint64

typedef uint64_t Uint64

An unsigned 64-bit integer type.

Since
This macro is available since SDL 3.2.0.
See also
SDL_UINT64_C

Definition at line 483 of file SDL_stdinc.h.

◆ Uint8

typedef uint8_t Uint8

An unsigned 8-bit integer type.

Since
This macro is available since SDL 3.2.0.

Definition at line 425 of file SDL_stdinc.h.

Function Documentation

◆ alloca()

void * alloca ( size_t )

◆ SDL_abs()

int SDL_abs ( int x)
extern

Compute the absolute value of x.

Parameters
xan integer value.
Returns
the absolute value of x.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_acos()

double SDL_acos ( double x)
extern

Compute the arc cosine of x.

The definition of y = acos(x) is x = cos(y).

Domain: -1 <= x <= 1

Range: 0 <= y <= Pi

This function operates on double-precision floating point values, use SDL_acosf for single-precision floats.

This function may use a different approximation across different versions, platforms and configurations. i.e, it can return a different value given the same input on different machines or operating systems, or if SDL is updated.

Parameters
xfloating point value.
Returns
arc cosine of x, in radians.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_acosf
SDL_asin
SDL_cos

◆ SDL_acosf()

float SDL_acosf ( float x)
extern

Compute the arc cosine of x.

The definition of y = acos(x) is x = cos(y).

Domain: -1 <= x <= 1

Range: 0 <= y <= Pi

This function operates on single-precision floating point values, use SDL_acos for double-precision floats.

This function may use a different approximation across different versions, platforms and configurations. i.e, it can return a different value given the same input on different machines or operating systems, or if SDL is updated.

Parameters
xfloating point value.
Returns
arc cosine of x, in radians.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_acos
SDL_asinf
SDL_cosf

◆ SDL_aligned_alloc()

SDL_MALLOC void * SDL_aligned_alloc ( size_t alignment,
size_t size )
extern

Allocate memory aligned to a specific alignment.

The memory returned by this function must be freed with SDL_aligned_free(), not SDL_free().

If alignment is less than the size of void *, it will be increased to match that.

The returned memory address will be a multiple of the alignment value, and the size of the memory allocated will be a multiple of the alignment value.

Parameters
alignmentthe alignment of the memory.
sizethe size to allocate.
Returns
a pointer to the aligned memory, or NULL if allocation failed.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_aligned_free

◆ SDL_aligned_free()

void SDL_aligned_free ( void * mem)
extern

Free memory allocated by SDL_aligned_alloc().

The pointer is no longer valid after this call and cannot be dereferenced anymore.

If mem is NULL, this function does nothing.

Parameters
mema pointer previously returned by SDL_aligned_alloc(), or NULL.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_aligned_alloc

◆ SDL_ALLOC_SIZE()

SDL_ALLOC_SIZE ( 2 )
extern

Change the size of allocated memory.

The memory returned by this function must be freed with SDL_free().

If size is 0, it will be set to 1. Note that this is unlike some other C runtime realloc implementations, which may treat realloc(mem, 0) the same way as free(mem).

If mem is NULL, the behavior of this function is equivalent to SDL_malloc(). Otherwise, the function can have one of three possible outcomes:

  • If it returns the same pointer as mem, it means that mem was resized in place without freeing.
  • If it returns a different non-NULL pointer, it means that mem was freed and cannot be dereferenced anymore.
  • If it returns NULL (indicating failure), then mem will remain valid and must still be freed with SDL_free().
Parameters
mema pointer to allocated memory to reallocate, or NULL.
sizethe new size of the memory.
Returns
a pointer to the newly allocated memory, or NULL if allocation failed.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_free
SDL_malloc
SDL_calloc

◆ SDL_ALLOC_SIZE2()

SDL_MALLOC SDL_ALLOC_SIZE2 ( 1 ,
2  )
extern

Allocate a zero-initialized array.

The memory returned by this function must be freed with SDL_free().

If either of nmemb or size is 0, they will both be set to 1.

Parameters
nmembthe number of elements in the array.
sizethe size of each element of the array.
Returns
a pointer to the allocated array, or NULL if allocation failed.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_free
SDL_malloc
SDL_realloc

◆ SDL_asin()

double SDL_asin ( double x)
extern

Compute the arc sine of x.

The definition of y = asin(x) is x = sin(y).

Domain: -1 <= x <= 1

Range: -Pi/2 <= y <= Pi/2

This function operates on double-precision floating point values, use SDL_asinf for single-precision floats.

This function may use a different approximation across different versions, platforms and configurations. i.e, it can return a different value given the same input on different machines or operating systems, or if SDL is updated.

Parameters
xfloating point value.
Returns
arc sine of x, in radians.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_asinf
SDL_acos
SDL_sin

◆ SDL_asinf()

float SDL_asinf ( float x)
extern

Compute the arc sine of x.

The definition of y = asin(x) is x = sin(y).

Domain: -1 <= x <= 1

Range: -Pi/2 <= y <= Pi/2

This function operates on single-precision floating point values, use SDL_asin for double-precision floats.

This function may use a different approximation across different versions, platforms and configurations. i.e, it can return a different value given the same input on different machines or operating systems, or if SDL is updated.

Parameters
xfloating point value.
Returns
arc sine of x, in radians.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_asin
SDL_acosf
SDL_sinf

◆ SDL_asprintf()

int SDL_asprintf ( char ** strp,
SDL_PRINTF_FORMAT_STRING const char * fmt,
... )
extern

This works exactly like asprintf() but doesn't require access to a C runtime.

Functions identically to SDL_snprintf(), except it allocates a buffer large enough to hold the output string on behalf of the caller.

On success, this function returns the number of bytes (not characters) comprising the output string, not counting the null-terminator character, and sets *strp to the newly-allocated string.

On error, this function returns a negative number, and the value of *strp is undefined.

The returned string is owned by the caller, and should be passed to SDL_free when no longer needed.

Parameters
strpon output, is set to the new string. Must not be NULL.
fmta printf-style format string. Must not be NULL.
...a list of values to be used with the format string.
Returns
the number of bytes in the newly-allocated string, not counting the null-terminator char, or a negative value on error.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_atan()

double SDL_atan ( double x)
extern

Compute the arc tangent of x.

The definition of y = atan(x) is x = tan(y).

Domain: -INF <= x <= INF

Range: -Pi/2 <= y <= Pi/2

This function operates on double-precision floating point values, use SDL_atanf for single-precision floats.

To calculate the arc tangent of y / x, use SDL_atan2.

This function may use a different approximation across different versions, platforms and configurations. i.e, it can return a different value given the same input on different machines or operating systems, or if SDL is updated.

Parameters
xfloating point value.
Returns
arc tangent of of x in radians, or 0 if x = 0.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_atanf
SDL_atan2
SDL_tan

◆ SDL_atan2()

double SDL_atan2 ( double y,
double x )
extern

Compute the arc tangent of y / x, using the signs of x and y to adjust the result's quadrant.

The definition of z = atan2(x, y) is y = x tan(z), where the quadrant of z is determined based on the signs of x and y.

Domain: -INF <= x <= INF, -INF <= y <= INF

Range: -Pi/2 <= y <= Pi/2

This function operates on double-precision floating point values, use SDL_atan2f for single-precision floats.

To calculate the arc tangent of a single value, use SDL_atan.

This function may use a different approximation across different versions, platforms and configurations. i.e, it can return a different value given the same input on different machines or operating systems, or if SDL is updated.

Parameters
yfloating point value of the numerator (y coordinate).
xfloating point value of the denominator (x coordinate).
Returns
arc tangent of of y / x in radians, or, if x = 0, either -Pi/2, 0, or Pi/2, depending on the value of y.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_atan2f
SDL_atan
SDL_tan

◆ SDL_atan2f()

float SDL_atan2f ( float y,
float x )
extern

Compute the arc tangent of y / x, using the signs of x and y to adjust the result's quadrant.

The definition of z = atan2(x, y) is y = x tan(z), where the quadrant of z is determined based on the signs of x and y.

Domain: -INF <= x <= INF, -INF <= y <= INF

Range: -Pi/2 <= y <= Pi/2

This function operates on single-precision floating point values, use SDL_atan2 for double-precision floats.

To calculate the arc tangent of a single value, use SDL_atanf.

This function may use a different approximation across different versions, platforms and configurations. i.e, it can return a different value given the same input on different machines or operating systems, or if SDL is updated.

Parameters
yfloating point value of the numerator (y coordinate).
xfloating point value of the denominator (x coordinate).
Returns
arc tangent of of y / x in radians, or, if x = 0, either -Pi/2, 0, or Pi/2, depending on the value of y.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_atan2
SDL_atan
SDL_tan

◆ SDL_atanf()

float SDL_atanf ( float x)
extern

Compute the arc tangent of x.

The definition of y = atan(x) is x = tan(y).

Domain: -INF <= x <= INF

Range: -Pi/2 <= y <= Pi/2

This function operates on single-precision floating point values, use SDL_atan for dboule-precision floats.

To calculate the arc tangent of y / x, use SDL_atan2f.

This function may use a different approximation across different versions, platforms and configurations. i.e, it can return a different value given the same input on different machines or operating systems, or if SDL is updated.

Parameters
xfloating point value.
Returns
arc tangent of of x in radians, or 0 if x = 0.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_atan
SDL_atan2f
SDL_tanf

◆ SDL_atof()

double SDL_atof ( const char * str)
extern

Parse a double from a string.

The result of calling SDL_atof(str) is equivalent to SDL_strtod(str, NULL).

Parameters
strThe null-terminated string to read. Must not be NULL.
Returns
the parsed double.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_atoi
SDL_strtol
SDL_strtoul
SDL_strtoll
SDL_strtoull
SDL_strtod

◆ SDL_atoi()

int SDL_atoi ( const char * str)
extern

Parse an int from a string.

The result of calling SDL_atoi(str) is equivalent to (int)SDL_strtol(str, NULL, 10).

Parameters
strThe null-terminated string to read. Must not be NULL.
Returns
the parsed int.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_atof
SDL_strtol
SDL_strtoul
SDL_strtoll
SDL_strtoull
SDL_strtod
SDL_itoa

◆ SDL_bsearch()

void * SDL_bsearch ( const void * key,
const void * base,
size_t nmemb,
size_t size,
SDL_CompareCallback compare )
extern

Perform a binary search on a previously sorted array.

For example:

typedef struct {
int key;
const char *string;
} data;
int SDLCALL compare(const void *a, const void *b)
{
const data *A = (const data *)a;
const data *B = (const data *)b;
if (A->n < B->n) {
return -1;
} else if (B->n < A->n) {
return 1;
} else {
return 0;
}
}
data values[] = {
{ 1, "first" }, { 2, "second" }, { 3, "third" }
};
data key = { 2, NULL };
data *result = SDL_bsearch(&key, values, SDL_arraysize(values), sizeof(values[0]), compare);
#define SDL_arraysize(array)
Definition SDL_stdinc.h:225
void * SDL_bsearch(const void *key, const void *base, size_t nmemb, size_t size, SDL_CompareCallback compare)
Parameters
keya pointer to a key equal to the element being searched for.
basea pointer to the start of the array.
nmembthe number of elements in the array.
sizethe size of the elements in the array.
comparea function used to compare elements in the array.
Returns
a pointer to the matching element in the array, or NULL if not found.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_bsearch_r
SDL_qsort

◆ SDL_bsearch_r()

void * SDL_bsearch_r ( const void * key,
const void * base,
size_t nmemb,
size_t size,
SDL_CompareCallback_r compare,
void * userdata )
extern

Perform a binary search on a previously sorted array, passing a userdata pointer to the compare function.

For example:

typedef enum {
sort_increasing,
sort_decreasing,
} sort_method;
typedef struct {
int key;
const char *string;
} data;
int SDLCALL compare(const void *userdata, const void *a, const void *b)
{
sort_method method = (sort_method)(uintptr_t)userdata;
const data *A = (const data *)a;
const data *B = (const data *)b;
if (A->key < B->key) {
return (method == sort_increasing) ? -1 : 1;
} else if (B->key < A->key) {
return (method == sort_increasing) ? 1 : -1;
} else {
return 0;
}
}
data values[] = {
{ 1, "first" }, { 2, "second" }, { 3, "third" }
};
data key = { 2, NULL };
data *result = SDL_bsearch_r(&key, values, SDL_arraysize(values), sizeof(values[0]), compare, (const void *)(uintptr_t)sort_increasing);
void * SDL_bsearch_r(const void *key, const void *base, size_t nmemb, size_t size, SDL_CompareCallback_r compare, void *userdata)
Parameters
keya pointer to a key equal to the element being searched for.
basea pointer to the start of the array.
nmembthe number of elements in the array.
sizethe size of the elements in the array.
comparea function used to compare elements in the array.
userdataa pointer to pass to the compare function.
Returns
a pointer to the matching element in the array, or NULL if not found.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_bsearch
SDL_qsort_r

◆ SDL_ceil()

double SDL_ceil ( double x)
extern

Compute the ceiling of x.

The ceiling of x is the smallest integer y such that y > x, i.e x rounded up to the nearest integer.

Domain: -INF <= x <= INF

Range: -INF <= y <= INF, y integer

This function operates on double-precision floating point values, use SDL_ceilf for single-precision floats.

Parameters
xfloating point value.
Returns
the ceiling of x.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_ceilf
SDL_floor
SDL_trunc
SDL_round
SDL_lround

◆ SDL_ceilf()

float SDL_ceilf ( float x)
extern

Compute the ceiling of x.

The ceiling of x is the smallest integer y such that y > x, i.e x rounded up to the nearest integer.

Domain: -INF <= x <= INF

Range: -INF <= y <= INF, y integer

This function operates on single-precision floating point values, use SDL_ceil for double-precision floats.

Parameters
xfloating point value.
Returns
the ceiling of x.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_ceil
SDL_floorf
SDL_truncf
SDL_roundf
SDL_lroundf

◆ SDL_copysign()

double SDL_copysign ( double x,
double y )
extern

Copy the sign of one floating-point value to another.

The definition of copysign is that copysign(x, y) = abs(x) * sign(y).

Domain: -INF <= x <= INF, -INF <= y <= f

Range: -INF <= z <= INF

This function operates on double-precision floating point values, use SDL_copysignf for single-precision floats.

Parameters
xfloating point value to use as the magnitude.
yfloating point value to use as the sign.
Returns
the floating point value with the sign of y and the magnitude of x.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_copysignf
SDL_fabs

◆ SDL_copysignf()

float SDL_copysignf ( float x,
float y )
extern

Copy the sign of one floating-point value to another.

The definition of copysign is that copysign(x, y) = abs(x) * sign(y).

Domain: -INF <= x <= INF, -INF <= y <= f

Range: -INF <= z <= INF

This function operates on single-precision floating point values, use SDL_copysign for double-precision floats.

Parameters
xfloating point value to use as the magnitude.
yfloating point value to use as the sign.
Returns
the floating point value with the sign of y and the magnitude of x.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_copysign
SDL_fabsf

◆ SDL_cos()

double SDL_cos ( double x)
extern

Compute the cosine of x.

Domain: -INF <= x <= INF

Range: -1 <= y <= 1

This function operates on double-precision floating point values, use SDL_cosf for single-precision floats.

This function may use a different approximation across different versions, platforms and configurations. i.e, it can return a different value given the same input on different machines or operating systems, or if SDL is updated.

Parameters
xfloating point value, in radians.
Returns
cosine of x.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_cosf
SDL_acos
SDL_sin

◆ SDL_cosf()

float SDL_cosf ( float x)
extern

Compute the cosine of x.

Domain: -INF <= x <= INF

Range: -1 <= y <= 1

This function operates on single-precision floating point values, use SDL_cos for double-precision floats.

This function may use a different approximation across different versions, platforms and configurations. i.e, it can return a different value given the same input on different machines or operating systems, or if SDL is updated.

Parameters
xfloating point value, in radians.
Returns
cosine of x.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_cos
SDL_acosf
SDL_sinf

◆ SDL_crc16()

Uint16 SDL_crc16 ( Uint16 crc,
const void * data,
size_t len )
extern

Calculate a CRC-16 value.

https://en.wikipedia.org/wiki/Cyclic_redundancy_check

This function can be called multiple times, to stream data to be checksummed in blocks. Each call must provide the previous CRC-16 return value to be updated with the next block. The first call to this function for a set of blocks should pass in a zero CRC value.

Parameters
crcthe current checksum for this data set, or 0 for a new data set.
dataa new block of data to add to the checksum.
lenthe size, in bytes, of the new block of data.
Returns
a CRC-16 checksum value of all blocks in the data set.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_crc32()

Uint32 SDL_crc32 ( Uint32 crc,
const void * data,
size_t len )
extern

Calculate a CRC-32 value.

https://en.wikipedia.org/wiki/Cyclic_redundancy_check

This function can be called multiple times, to stream data to be checksummed in blocks. Each call must provide the previous CRC-32 return value to be updated with the next block. The first call to this function for a set of blocks should pass in a zero CRC value.

Parameters
crcthe current checksum for this data set, or 0 for a new data set.
dataa new block of data to add to the checksum.
lenthe size, in bytes, of the new block of data.
Returns
a CRC-32 checksum value of all blocks in the data set.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_CreateEnvironment()

SDL_Environment * SDL_CreateEnvironment ( bool populated)
extern

Create a set of environment variables

Parameters
populatedtrue to initialize it from the C runtime environment, false to create an empty environment.
Returns
a pointer to the new environment or NULL on failure; call SDL_GetError() for more information.

\threadsafety If populated is false, it is safe to call this function from any thread, otherwise it is safe if no other threads are calling setenv() or unsetenv()

Since
This function is available since SDL 3.2.0.
See also
SDL_GetEnvironmentVariable
SDL_GetEnvironmentVariables
SDL_SetEnvironmentVariable
SDL_UnsetEnvironmentVariable
SDL_DestroyEnvironment

◆ SDL_DestroyEnvironment()

void SDL_DestroyEnvironment ( SDL_Environment * env)
extern

Destroy a set of environment variables.

Parameters
envthe environment to destroy.

\threadsafety It is safe to call this function from any thread, as long as the environment is no longer in use.

Since
This function is available since SDL 3.2.0.
See also
SDL_CreateEnvironment

◆ SDL_exp()

double SDL_exp ( double x)
extern

Compute the exponential of x.

The definition of y = exp(x) is y = e^x, where e is the base of the natural logarithm. The inverse is the natural logarithm, SDL_log.

Domain: -INF <= x <= INF

Range: 0 <= y <= INF

The output will overflow if exp(x) is too large to be represented.

This function operates on double-precision floating point values, use SDL_expf for single-precision floats.

This function may use a different approximation across different versions, platforms and configurations. i.e, it can return a different value given the same input on different machines or operating systems, or if SDL is updated.

Parameters
xfloating point value.
Returns
value of e^x.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_expf
SDL_log

◆ SDL_expf()

float SDL_expf ( float x)
extern

Compute the exponential of x.

The definition of y = exp(x) is y = e^x, where e is the base of the natural logarithm. The inverse is the natural logarithm, SDL_logf.

Domain: -INF <= x <= INF

Range: 0 <= y <= INF

The output will overflow if exp(x) is too large to be represented.

This function operates on single-precision floating point values, use SDL_exp for double-precision floats.

This function may use a different approximation across different versions, platforms and configurations. i.e, it can return a different value given the same input on different machines or operating systems, or if SDL is updated.

Parameters
xfloating point value.
Returns
value of e^x.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_exp
SDL_logf

◆ SDL_fabs()

double SDL_fabs ( double x)
extern

Compute the absolute value of x

Domain: -INF <= x <= INF

Range: 0 <= y <= INF

This function operates on double-precision floating point values, use SDL_fabsf for single-precision floats.

Parameters
xfloating point value to use as the magnitude.
Returns
the absolute value of x.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_fabsf

◆ SDL_fabsf()

float SDL_fabsf ( float x)
extern

Compute the absolute value of x

Domain: -INF <= x <= INF

Range: 0 <= y <= INF

This function operates on single-precision floating point values, use SDL_fabs for double-precision floats.

Parameters
xfloating point value to use as the magnitude.
Returns
the absolute value of x.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_fabs

Referenced by SDL_RectsEqualEpsilon().

◆ SDL_floor()

double SDL_floor ( double x)
extern

Compute the floor of x.

The floor of x is the largest integer y such that y > x, i.e x rounded down to the nearest integer.

Domain: -INF <= x <= INF

Range: -INF <= y <= INF, y integer

This function operates on double-precision floating point values, use SDL_floorf for single-precision floats.

Parameters
xfloating point value.
Returns
the floor of x.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_floorf
SDL_ceil
SDL_trunc
SDL_round
SDL_lround

◆ SDL_floorf()

float SDL_floorf ( float x)
extern

Compute the floor of x.

The floor of x is the largest integer y such that y > x, i.e x rounded down to the nearest integer.

Domain: -INF <= x <= INF

Range: -INF <= y <= INF, y integer

This function operates on single-precision floating point values, use SDL_floor for double-precision floats.

Parameters
xfloating point value.
Returns
the floor of x.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_floor
SDL_ceilf
SDL_truncf
SDL_roundf
SDL_lroundf

◆ SDL_fmod()

double SDL_fmod ( double x,
double y )
extern

Return the floating-point remainder of x / y

Divides x by y, and returns the remainder.

Domain: -INF <= x <= INF, -INF <= y <= INF, y != 0

Range: -y <= z <= y

This function operates on double-precision floating point values, use SDL_fmodf for single-precision floats.

Parameters
xthe numerator.
ythe denominator. Must not be 0.
Returns
the remainder of x / y.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_fmodf
SDL_modf
SDL_trunc
SDL_ceil
SDL_floor
SDL_round
SDL_lround

◆ SDL_fmodf()

float SDL_fmodf ( float x,
float y )
extern

Return the floating-point remainder of x / y

Divides x by y, and returns the remainder.

Domain: -INF <= x <= INF, -INF <= y <= INF, y != 0

Range: -y <= z <= y

This function operates on single-precision floating point values, use SDL_fmod for double-precision floats.

Parameters
xthe numerator.
ythe denominator. Must not be 0.
Returns
the remainder of x / y.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_fmod
SDL_truncf
SDL_modff
SDL_ceilf
SDL_floorf
SDL_roundf
SDL_lroundf

◆ SDL_free()

void SDL_free ( void * mem)
extern

Free allocated memory.

The pointer is no longer valid after this call and cannot be dereferenced anymore.

If mem is NULL, this function does nothing.

Parameters
mema pointer to allocated memory, or NULL.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_malloc
SDL_calloc
SDL_realloc

◆ SDL_getenv()

const char * SDL_getenv ( const char * name)
extern

Get the value of a variable in the environment.

This function uses SDL's cached copy of the environment and is thread-safe.

Parameters
namethe name of the variable to get.
Returns
a pointer to the value of the variable or NULL if it can't be found.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_getenv_unsafe()

const char * SDL_getenv_unsafe ( const char * name)
extern

Get the value of a variable in the environment.

This function bypasses SDL's cached copy of the environment and is not thread-safe.

Parameters
namethe name of the variable to get.
Returns
a pointer to the value of the variable or NULL if it can't be found.

\threadsafety This function is not thread safe, consider using SDL_getenv() instead.

Since
This function is available since SDL 3.2.0.
See also
SDL_getenv

◆ SDL_GetEnvironment()

SDL_Environment * SDL_GetEnvironment ( void )
extern

Get the process environment.

This is initialized at application start and is not affected by setenv() and unsetenv() calls after that point. Use SDL_SetEnvironmentVariable() and SDL_UnsetEnvironmentVariable() if you want to modify this environment, or SDL_setenv_unsafe() or SDL_unsetenv_unsafe() if you want changes to persist in the C runtime environment after SDL_Quit().

Returns
a pointer to the environment for the process or NULL on failure; call SDL_GetError() for more information.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_GetEnvironmentVariable
SDL_GetEnvironmentVariables
SDL_SetEnvironmentVariable
SDL_UnsetEnvironmentVariable

◆ SDL_GetEnvironmentVariable()

const char * SDL_GetEnvironmentVariable ( SDL_Environment * env,
const char * name )
extern

Get the value of a variable in the environment.

Parameters
envthe environment to query.
namethe name of the variable to get.
Returns
a pointer to the value of the variable or NULL if it can't be found.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_GetEnvironment
SDL_CreateEnvironment
SDL_GetEnvironmentVariables
SDL_SetEnvironmentVariable
SDL_UnsetEnvironmentVariable

◆ SDL_GetEnvironmentVariables()

char ** SDL_GetEnvironmentVariables ( SDL_Environment * env)
extern

Get all variables in the environment.

Parameters
envthe environment to query.
Returns
a NULL terminated array of pointers to environment variables in the form "variable=value" or NULL on failure; call SDL_GetError() for more information. This is a single allocation that should be freed with SDL_free() when it is no longer needed.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_GetEnvironment
SDL_CreateEnvironment
SDL_GetEnvironmentVariables
SDL_SetEnvironmentVariable
SDL_UnsetEnvironmentVariable

◆ SDL_GetMemoryFunctions()

void SDL_GetMemoryFunctions ( SDL_malloc_func * malloc_func,
SDL_calloc_func * calloc_func,
SDL_realloc_func * realloc_func,
SDL_free_func * free_func )
extern

Get the current set of SDL memory functions.

Parameters
malloc_funcfilled with malloc function.
calloc_funcfilled with calloc function.
realloc_funcfilled with realloc function.
free_funcfilled with free function.

\threadsafety This does not hold a lock, so do not call this in the unlikely event of a background thread calling SDL_SetMemoryFunctions simultaneously.

Since
This function is available since SDL 3.2.0.
See also
SDL_SetMemoryFunctions
SDL_GetOriginalMemoryFunctions

◆ SDL_GetNumAllocations()

int SDL_GetNumAllocations ( void )
extern

Get the number of outstanding (unfreed) allocations.

Returns
the number of allocations or -1 if allocation counting is disabled.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_GetOriginalMemoryFunctions()

void SDL_GetOriginalMemoryFunctions ( SDL_malloc_func * malloc_func,
SDL_calloc_func * calloc_func,
SDL_realloc_func * realloc_func,
SDL_free_func * free_func )
extern

Get the original set of SDL memory functions.

This is what SDL_malloc and friends will use by default, if there has been no call to SDL_SetMemoryFunctions. This is not necessarily using the C runtime's malloc functions behind the scenes! Different platforms and build configurations might do any number of unexpected things.

Parameters
malloc_funcfilled with malloc function.
calloc_funcfilled with calloc function.
realloc_funcfilled with realloc function.
free_funcfilled with free function.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_iconv()

size_t SDL_iconv ( SDL_iconv_t cd,
const char ** inbuf,
size_t * inbytesleft,
char ** outbuf,
size_t * outbytesleft )
extern

This function converts text between encodings, reading from and writing to a buffer.

It returns the number of succesful conversions on success. On error, SDL_ICONV_E2BIG is returned when the output buffer is too small, or SDL_ICONV_EILSEQ is returned when an invalid input sequence is encountered, or SDL_ICONV_EINVAL is returned when an incomplete input sequence is encountered.

On exit:

  • inbuf will point to the beginning of the next multibyte sequence. On error, this is the location of the problematic input sequence. On success, this is the end of the input sequence.
  • inbytesleft will be set to the number of bytes left to convert, which will be 0 on success.
  • outbuf will point to the location where to store the next output byte.
  • outbytesleft will be set to the number of bytes left in the output buffer.
Parameters
cdThe character set conversion context, created in SDL_iconv_open().
inbufAddress of variable that points to the first character of the input sequence.
inbytesleftThe number of bytes in the input buffer.
outbufAddress of variable that points to the output buffer.
outbytesleftThe number of bytes in the output buffer.
Returns
the number of conversions on success, or a negative error code.
Since
This function is available since SDL 3.2.0.
See also
SDL_iconv_open
SDL_iconv_close
SDL_iconv_string

◆ SDL_iconv_close()

int SDL_iconv_close ( SDL_iconv_t cd)
extern

This function frees a context used for character set conversion.

Parameters
cdThe character set conversion handle.
Returns
0 on success, or -1 on failure.
Since
This function is available since SDL 3.2.0.
See also
SDL_iconv
SDL_iconv_open
SDL_iconv_string

◆ SDL_iconv_open()

SDL_iconv_t SDL_iconv_open ( const char * tocode,
const char * fromcode )
extern

This function allocates a context for the specified character set conversion.

Parameters
tocodeThe target character encoding, must not be NULL.
fromcodeThe source character encoding, must not be NULL.
Returns
a handle that must be freed with SDL_iconv_close, or SDL_ICONV_ERROR on failure.
Since
This function is available since SDL 3.2.0.
See also
SDL_iconv
SDL_iconv_close
SDL_iconv_string

◆ SDL_iconv_string()

char * SDL_iconv_string ( const char * tocode,
const char * fromcode,
const char * inbuf,
size_t inbytesleft )
extern

Helper function to convert a string's encoding in one call.

This function converts a buffer or string between encodings in one pass.

The string does not need to be NULL-terminated; this function operates on the number of bytes specified in inbytesleft whether there is a NULL character anywhere in the buffer.

The returned string is owned by the caller, and should be passed to SDL_free when no longer needed.

Parameters
tocodethe character encoding of the output string. Examples are "UTF-8", "UCS-4", etc.
fromcodethe character encoding of data in inbuf.
inbufthe string to convert to a different encoding.
inbytesleftthe size of the input string in bytes.
Returns
a new string, converted to the new encoding, or NULL on error.
Since
This function is available since SDL 3.2.0.
See also
SDL_iconv_open
SDL_iconv_close
SDL_iconv

◆ SDL_isalnum()

int SDL_isalnum ( int x)
extern

Query if a character is alphabetic (a letter) or a number.

WARNING: Regardless of system locale, this will only treat ASCII values for English 'a-z', 'A-Z', and '0-9' as true.

Parameters
xcharacter value to check.
Returns
non-zero if x falls within the character class, zero otherwise.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_isalpha()

int SDL_isalpha ( int x)
extern

Query if a character is alphabetic (a letter).

WARNING: Regardless of system locale, this will only treat ASCII values for English 'a-z' and 'A-Z' as true.

Parameters
xcharacter value to check.
Returns
non-zero if x falls within the character class, zero otherwise.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_isblank()

int SDL_isblank ( int x)
extern

Report if a character is blank (a space or tab).

WARNING: Regardless of system locale, this will only treat ASCII values 0x20 (space) or 0x9 (tab) as true.

Parameters
xcharacter value to check.
Returns
non-zero if x falls within the character class, zero otherwise.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_iscntrl()

int SDL_iscntrl ( int x)
extern

Report if a character is a control character.

WARNING: Regardless of system locale, this will only treat ASCII values 0 through 0x1F, and 0x7F, as true.

Parameters
xcharacter value to check.
Returns
non-zero if x falls within the character class, zero otherwise.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_isdigit()

int SDL_isdigit ( int x)
extern

Report if a character is a numeric digit.

WARNING: Regardless of system locale, this will only treat ASCII values '0' (0x30) through '9' (0x39), as true.

Parameters
xcharacter value to check.
Returns
non-zero if x falls within the character class, zero otherwise.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_isgraph()

int SDL_isgraph ( int x)
extern

Report if a character is any "printable" except space.

Be advised that "printable" has a definition that goes back to text terminals from the dawn of computing, making this a sort of special case function that is not suitable for Unicode (or most any) text management.

WARNING: Regardless of system locale, this is equivalent to ‘(SDL_isprint(x)) && ((x) != ’ ')`.

Parameters
xcharacter value to check.
Returns
non-zero if x falls within the character class, zero otherwise.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_isprint

◆ SDL_isinf()

int SDL_isinf ( double x)
extern

Return whether the value is infinity.

Parameters
xdouble-precision floating point value.
Returns
non-zero if the value is infinity, 0 otherwise.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_isinff

◆ SDL_isinff()

int SDL_isinff ( float x)
extern

Return whether the value is infinity.

Parameters
xfloating point value.
Returns
non-zero if the value is infinity, 0 otherwise.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_isinf

◆ SDL_islower()

int SDL_islower ( int x)
extern

Report if a character is lower case.

WARNING: Regardless of system locale, this will only treat ASCII values 'a' through 'z' as true.

Parameters
xcharacter value to check.
Returns
non-zero if x falls within the character class, zero otherwise.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_isnan()

int SDL_isnan ( double x)
extern

Return whether the value is NaN.

Parameters
xdouble-precision floating point value.
Returns
non-zero if the value is NaN, 0 otherwise.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_isnanf

◆ SDL_isnanf()

int SDL_isnanf ( float x)
extern

Return whether the value is NaN.

Parameters
xfloating point value.
Returns
non-zero if the value is NaN, 0 otherwise.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_isnan

◆ SDL_isprint()

int SDL_isprint ( int x)
extern

Report if a character is "printable".

Be advised that "printable" has a definition that goes back to text terminals from the dawn of computing, making this a sort of special case function that is not suitable for Unicode (or most any) text management.

WARNING: Regardless of system locale, this will only treat ASCII values ' ' (0x20) through '~' (0x7E) as true.

Parameters
xcharacter value to check.
Returns
non-zero if x falls within the character class, zero otherwise.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_ispunct()

int SDL_ispunct ( int x)
extern

Report if a character is a punctuation mark.

WARNING: Regardless of system locale, this is equivalent to ((SDL_isgraph(x)) && (!SDL_isalnum(x))).

Parameters
xcharacter value to check.
Returns
non-zero if x falls within the character class, zero otherwise.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_isgraph
SDL_isalnum

◆ SDL_isspace()

int SDL_isspace ( int x)
extern

Report if a character is whitespace.

WARNING: Regardless of system locale, this will only treat the following ASCII values as true:

  • space (0x20)
  • tab (0x09)
  • newline (0x0A)
  • vertical tab (0x0B)
  • form feed (0x0C)
  • return (0x0D)
Parameters
xcharacter value to check.
Returns
non-zero if x falls within the character class, zero otherwise.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_isupper()

int SDL_isupper ( int x)
extern

Report if a character is upper case.

WARNING: Regardless of system locale, this will only treat ASCII values 'A' through 'Z' as true.

Parameters
xcharacter value to check.
Returns
non-zero if x falls within the character class, zero otherwise.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_isxdigit()

int SDL_isxdigit ( int x)
extern

Report if a character is a hexadecimal digit.

WARNING: Regardless of system locale, this will only treat ASCII values 'A' through 'F', 'a' through 'f', and '0' through '9', as true.

Parameters
xcharacter value to check.
Returns
non-zero if x falls within the character class, zero otherwise.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_itoa()

char * SDL_itoa ( int value,
char * str,
int radix )
extern

Convert an integer into a string.

This requires a radix to specified for string format. Specifying 10 produces a decimal number, 16 hexidecimal, etc. Must be in the range of 2 to 36.

Note that this function will overflow a buffer if str is not large enough to hold the output! It may be safer to use SDL_snprintf to clamp output, or SDL_asprintf to allocate a buffer. Otherwise, it doesn't hurt to allocate much more space than you expect to use (and don't forget possible negative signs, null terminator bytes, etc).

Parameters
valuethe integer to convert.
strthe buffer to write the string into.
radixthe radix to use for string generation.
Returns
str.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_uitoa
SDL_ltoa
SDL_lltoa

◆ SDL_lltoa()

char * SDL_lltoa ( long long value,
char * str,
int radix )
extern

Convert a long long integer into a string.

This requires a radix to specified for string format. Specifying 10 produces a decimal number, 16 hexidecimal, etc. Must be in the range of 2 to 36.

Note that this function will overflow a buffer if str is not large enough to hold the output! It may be safer to use SDL_snprintf to clamp output, or SDL_asprintf to allocate a buffer. Otherwise, it doesn't hurt to allocate much more space than you expect to use (and don't forget possible negative signs, null terminator bytes, etc).

Parameters
valuethe long long integer to convert.
strthe buffer to write the string into.
radixthe radix to use for string generation.
Returns
str.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_ulltoa
SDL_itoa
SDL_ltoa

◆ SDL_log()

double SDL_log ( double x)
extern

Compute the natural logarithm of x.

Domain: 0 < x <= INF

Range: -INF <= y <= INF

It is an error for x to be less than or equal to 0.

This function operates on double-precision floating point values, use SDL_logf for single-precision floats.

This function may use a different approximation across different versions, platforms and configurations. i.e, it can return a different value given the same input on different machines or operating systems, or if SDL is updated.

Parameters
xfloating point value. Must be greater than 0.
Returns
the natural logarithm of x.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_logf
SDL_log10
SDL_exp

◆ SDL_log10()

double SDL_log10 ( double x)
extern

Compute the base-10 logarithm of x.

Domain: 0 < x <= INF

Range: -INF <= y <= INF

It is an error for x to be less than or equal to 0.

This function operates on double-precision floating point values, use SDL_log10f for single-precision floats.

This function may use a different approximation across different versions, platforms and configurations. i.e, it can return a different value given the same input on different machines or operating systems, or if SDL is updated.

Parameters
xfloating point value. Must be greater than 0.
Returns
the logarithm of x.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_log10f
SDL_log
SDL_pow

◆ SDL_log10f()

float SDL_log10f ( float x)
extern

Compute the base-10 logarithm of x.

Domain: 0 < x <= INF

Range: -INF <= y <= INF

It is an error for x to be less than or equal to 0.

This function operates on single-precision floating point values, use SDL_log10 for double-precision floats.

This function may use a different approximation across different versions, platforms and configurations. i.e, it can return a different value given the same input on different machines or operating systems, or if SDL is updated.

Parameters
xfloating point value. Must be greater than 0.
Returns
the logarithm of x.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_log10
SDL_logf
SDL_powf

◆ SDL_logf()

float SDL_logf ( float x)
extern

Compute the natural logarithm of x.

Domain: 0 < x <= INF

Range: -INF <= y <= INF

It is an error for x to be less than or equal to 0.

This function operates on single-precision floating point values, use SDL_log for double-precision floats.

This function may use a different approximation across different versions, platforms and configurations. i.e, it can return a different value given the same input on different machines or operating systems, or if SDL is updated.

Parameters
xfloating point value. Must be greater than 0.
Returns
the natural logarithm of x.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_log
SDL_expf

◆ SDL_lround()

long SDL_lround ( double x)
extern

Round x to the nearest integer representable as a long

Rounds x to the nearest integer. Values halfway between integers will be rounded away from zero.

Domain: -INF <= x <= INF

Range: MIN_LONG <= y <= MAX_LONG

This function operates on double-precision floating point values, use SDL_lroundf for single-precision floats. To get the result as a floating-point type, use SDL_round.

Parameters
xfloating point value.
Returns
the nearest integer to x.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_lroundf
SDL_round
SDL_floor
SDL_ceil
SDL_trunc

◆ SDL_lroundf()

long SDL_lroundf ( float x)
extern

Round x to the nearest integer representable as a long

Rounds x to the nearest integer. Values halfway between integers will be rounded away from zero.

Domain: -INF <= x <= INF

Range: MIN_LONG <= y <= MAX_LONG

This function operates on single-precision floating point values, use SDL_lround for double-precision floats. To get the result as a floating-point type, use SDL_roundf.

Parameters
xfloating point value.
Returns
the nearest integer to x.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_lround
SDL_roundf
SDL_floorf
SDL_ceilf
SDL_truncf

◆ SDL_ltoa()

char * SDL_ltoa ( long value,
char * str,
int radix )
extern

Convert a long integer into a string.

This requires a radix to specified for string format. Specifying 10 produces a decimal number, 16 hexidecimal, etc. Must be in the range of 2 to 36.

Note that this function will overflow a buffer if str is not large enough to hold the output! It may be safer to use SDL_snprintf to clamp output, or SDL_asprintf to allocate a buffer. Otherwise, it doesn't hurt to allocate much more space than you expect to use (and don't forget possible negative signs, null terminator bytes, etc).

Parameters
valuethe long integer to convert.
strthe buffer to write the string into.
radixthe radix to use for string generation.
Returns
str.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_ultoa
SDL_itoa
SDL_lltoa

◆ SDL_malloc()

SDL_MALLOC void * SDL_malloc ( size_t size)
extern

Allocate uninitialized memory.

The allocated memory returned by this function must be freed with SDL_free().

If size is 0, it will be set to 1.

If you want to allocate memory aligned to a specific alignment, consider using SDL_aligned_alloc().

Parameters
sizethe size to allocate.
Returns
a pointer to the allocated memory, or NULL if allocation failed.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_free
SDL_calloc
SDL_realloc
SDL_aligned_alloc

◆ SDL_memcmp()

int SDL_memcmp ( const void * s1,
const void * s2,
size_t len )
extern

Compare two buffers of memory.

Parameters
s1the first buffer to compare. NULL is not permitted!
s2the second buffer to compare. NULL is not permitted!
lenthe number of bytes to compare between the buffers.
Returns
less than zero if s1 is "less than" s2, greater than zero if s1 is "greater than" s2, and zero if the buffers match exactly for len bytes.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_memcpy()

void * SDL_memcpy ( SDL_OUT_BYTECAP(len) void * dst,
SDL_IN_BYTECAP(len) const void * src,
size_t len )
extern

Copy non-overlapping memory.

The memory regions must not overlap. If they do, use SDL_memmove() instead.

Parameters
dstThe destination memory region. Must not be NULL, and must not overlap with src.
srcThe source memory region. Must not be NULL, and must not overlap with dst.
lenThe length in bytes of both dst and src.
Returns
dst.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_memmove

◆ SDL_memmove()

void * SDL_memmove ( SDL_OUT_BYTECAP(len) void * dst,
SDL_IN_BYTECAP(len) const void * src,
size_t len )
extern

Copy memory ranges that might overlap.

It is okay for the memory regions to overlap. If you are confident that the regions never overlap, using SDL_memcpy() may improve performance.

Parameters
dstThe destination memory region. Must not be NULL.
srcThe source memory region. Must not be NULL.
lenThe length in bytes of both dst and src.
Returns
dst.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_memcpy

◆ SDL_memset()

void * SDL_memset ( SDL_OUT_BYTECAP(len) void * dst,
int c,
size_t len )
extern

Initialize all bytes of buffer of memory to a specific value.

This function will set len bytes, pointed to by dst, to the value specified in c.

Despite c being an int instead of a char, this only operates on bytes; c must be a value between 0 and 255, inclusive.

Parameters
dstthe destination memory region. Must not be NULL.
cthe byte value to set.
lenthe length, in bytes, to set in dst.
Returns
dst.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_memset4()

void * SDL_memset4 ( void * dst,
Uint32 val,
size_t dwords )
extern

Initialize all 32-bit words of buffer of memory to a specific value.

This function will set a buffer of dwords Uint32 values, pointed to by dst, to the value specified in val.

Unlike SDL_memset, this sets 32-bit values, not bytes, so it's not limited to a range of 0-255.

Parameters
dstthe destination memory region. Must not be NULL.
valthe Uint32 value to set.
dwordsthe number of Uint32 values to set in dst.
Returns
dst.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_modf()

double SDL_modf ( double x,
double * y )
extern

Split x into integer and fractional parts

This function operates on double-precision floating point values, use SDL_modff for single-precision floats.

Parameters
xfloating point value.
youtput pointer to store the integer part of x.
Returns
the fractional part of x.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_modff
SDL_trunc
SDL_fmod

◆ SDL_modff()

float SDL_modff ( float x,
float * y )
extern

Split x into integer and fractional parts

This function operates on single-precision floating point values, use SDL_modf for double-precision floats.

Parameters
xfloating point value.
youtput pointer to store the integer part of x.
Returns
the fractional part of x.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_modf
SDL_truncf
SDL_fmodf

◆ SDL_murmur3_32()

Uint32 SDL_murmur3_32 ( const void * data,
size_t len,
Uint32 seed )
extern

Calculate a 32-bit MurmurHash3 value for a block of data.

https://en.wikipedia.org/wiki/MurmurHash

A seed may be specified, which changes the final results consistently, but this does not work like SDL_crc16 and SDL_crc32: you can't feed a previous result from this function back into itself as the next seed value to calculate a hash in chunks; it won't produce the same hash as it would if the same data was provided in a single call.

If you aren't sure what to provide for a seed, zero is fine. Murmur3 is not cryptographically secure, so it shouldn't be used for hashing top-secret data.

Parameters
datathe data to be hashed.
lenthe size of data, in bytes.
seeda value that alters the final hash value.
Returns
a Murmur3 32-bit hash value.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_pow()

double SDL_pow ( double x,
double y )
extern

Raise x to the power y

Domain: -INF <= x <= INF, -INF <= y <= INF

Range: -INF <= z <= INF

If y is the base of the natural logarithm (e), consider using SDL_exp instead.

This function operates on double-precision floating point values, use SDL_powf for single-precision floats.

This function may use a different approximation across different versions, platforms and configurations. i.e, it can return a different value given the same input on different machines or operating systems, or if SDL is updated.

Parameters
xthe base.
ythe exponent.
Returns
x raised to the power y.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_powf
SDL_exp
SDL_log

◆ SDL_powf()

float SDL_powf ( float x,
float y )
extern

Raise x to the power y

Domain: -INF <= x <= INF, -INF <= y <= INF

Range: -INF <= z <= INF

If y is the base of the natural logarithm (e), consider using SDL_exp instead.

This function operates on single-precision floating point values, use SDL_pow for double-precision floats.

This function may use a different approximation across different versions, platforms and configurations. i.e, it can return a different value given the same input on different machines or operating systems, or if SDL is updated.

Parameters
xthe base.
ythe exponent.
Returns
x raised to the power y.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_pow
SDL_expf
SDL_logf

◆ SDL_qsort()

void SDL_qsort ( void * base,
size_t nmemb,
size_t size,
SDL_CompareCallback compare )
extern

Sort an array.

For example:

typedef struct {
int key;
const char *string;
} data;
int SDLCALL compare(const void *a, const void *b)
{
const data *A = (const data *)a;
const data *B = (const data *)b;
if (A->n < B->n) {
return -1;
} else if (B->n < A->n) {
return 1;
} else {
return 0;
}
}
data values[] = {
{ 3, "third" }, { 1, "first" }, { 2, "second" }
};
SDL_qsort(values, SDL_arraysize(values), sizeof(values[0]), compare);
void SDL_qsort(void *base, size_t nmemb, size_t size, SDL_CompareCallback compare)
Parameters
basea pointer to the start of the array.
nmembthe number of elements in the array.
sizethe size of the elements in the array.
comparea function used to compare elements in the array.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_bsearch
SDL_qsort_r

◆ SDL_qsort_r()

void SDL_qsort_r ( void * base,
size_t nmemb,
size_t size,
SDL_CompareCallback_r compare,
void * userdata )
extern

Sort an array, passing a userdata pointer to the compare function.

For example:

typedef enum {
sort_increasing,
sort_decreasing,
} sort_method;
typedef struct {
int key;
const char *string;
} data;
int SDLCALL compare(const void *userdata, const void *a, const void *b)
{
sort_method method = (sort_method)(uintptr_t)userdata;
const data *A = (const data *)a;
const data *B = (const data *)b;
if (A->key < B->key) {
return (method == sort_increasing) ? -1 : 1;
} else if (B->key < A->key) {
return (method == sort_increasing) ? 1 : -1;
} else {
return 0;
}
}
data values[] = {
{ 3, "third" }, { 1, "first" }, { 2, "second" }
};
SDL_qsort_r(values, SDL_arraysize(values), sizeof(values[0]), compare, (const void *)(uintptr_t)sort_increasing);
void SDL_qsort_r(void *base, size_t nmemb, size_t size, SDL_CompareCallback_r compare, void *userdata)
Parameters
basea pointer to the start of the array.
nmembthe number of elements in the array.
sizethe size of the elements in the array.
comparea function used to compare elements in the array.
userdataa pointer to pass to the compare function.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_bsearch_r
SDL_qsort

◆ SDL_rand()

Sint32 SDL_rand ( Sint32 n)
extern

Generate a pseudo-random number less than n for positive n

The method used is faster and of better quality than rand() % n. Odds are roughly 99.9% even for n = 1 million. Evenness is better for smaller n, and much worse as n gets bigger.

Example: to simulate a d6 use SDL_rand(6) + 1 The +1 converts 0..5 to 1..6

If you want to generate a pseudo-random number in the full range of Sint32, you should use: (Sint32)SDL_rand_bits()

If you want reproducible output, be sure to initialize with SDL_srand() first.

There are no guarantees as to the quality of the random sequence produced, and this should not be used for security (cryptography, passwords) or where money is on the line (loot-boxes, casinos). There are many random number libraries available with different characteristics and you should pick one of those to meet any serious needs.

Parameters
nthe number of possible outcomes. n must be positive.
Returns
a random value in the range of [0 .. n-1].

\threadsafety All calls should be made from a single thread

Since
This function is available since SDL 3.2.0.
See also
SDL_srand
SDL_randf

◆ SDL_rand_bits()

Uint32 SDL_rand_bits ( void )
extern

Generate 32 pseudo-random bits.

You likely want to use SDL_rand() to get a psuedo-random number instead.

There are no guarantees as to the quality of the random sequence produced, and this should not be used for security (cryptography, passwords) or where money is on the line (loot-boxes, casinos). There are many random number libraries available with different characteristics and you should pick one of those to meet any serious needs.

Returns
a random value in the range of [0-SDL_MAX_UINT32].

\threadsafety All calls should be made from a single thread

Since
This function is available since SDL 3.2.0.
See also
SDL_rand
SDL_randf
SDL_srand

◆ SDL_rand_bits_r()

Uint32 SDL_rand_bits_r ( Uint64 * state)
extern

Generate 32 pseudo-random bits.

You likely want to use SDL_rand_r() to get a psuedo-random number instead.

There are no guarantees as to the quality of the random sequence produced, and this should not be used for security (cryptography, passwords) or where money is on the line (loot-boxes, casinos). There are many random number libraries available with different characteristics and you should pick one of those to meet any serious needs.

Parameters
statea pointer to the current random number state, this may not be NULL.
Returns
a random value in the range of [0-SDL_MAX_UINT32].

\threadsafety This function is thread-safe, as long as the state pointer isn't shared between threads.

Since
This function is available since SDL 3.2.0.
See also
SDL_rand_r
SDL_randf_r

◆ SDL_rand_r()

Sint32 SDL_rand_r ( Uint64 * state,
Sint32 n )
extern

Generate a pseudo-random number less than n for positive n

The method used is faster and of better quality than rand() % n. Odds are roughly 99.9% even for n = 1 million. Evenness is better for smaller n, and much worse as n gets bigger.

Example: to simulate a d6 use SDL_rand_r(state, 6) + 1 The +1 converts 0..5 to 1..6

If you want to generate a pseudo-random number in the full range of Sint32, you should use: (Sint32)SDL_rand_bits_r(state)

There are no guarantees as to the quality of the random sequence produced, and this should not be used for security (cryptography, passwords) or where money is on the line (loot-boxes, casinos). There are many random number libraries available with different characteristics and you should pick one of those to meet any serious needs.

Parameters
statea pointer to the current random number state, this may not be NULL.
nthe number of possible outcomes. n must be positive.
Returns
a random value in the range of [0 .. n-1].

\threadsafety This function is thread-safe, as long as the state pointer isn't shared between threads.

Since
This function is available since SDL 3.2.0.
See also
SDL_rand
SDL_rand_bits_r
SDL_randf_r

◆ SDL_randf()

float SDL_randf ( void )
extern

Generate a uniform pseudo-random floating point number less than 1.0

If you want reproducible output, be sure to initialize with SDL_srand() first.

There are no guarantees as to the quality of the random sequence produced, and this should not be used for security (cryptography, passwords) or where money is on the line (loot-boxes, casinos). There are many random number libraries available with different characteristics and you should pick one of those to meet any serious needs.

Returns
a random value in the range of [0.0, 1.0).

\threadsafety All calls should be made from a single thread

Since
This function is available since SDL 3.2.0.
See also
SDL_srand
SDL_rand

◆ SDL_randf_r()

float SDL_randf_r ( Uint64 * state)
extern

Generate a uniform pseudo-random floating point number less than 1.0

If you want reproducible output, be sure to initialize with SDL_srand() first.

There are no guarantees as to the quality of the random sequence produced, and this should not be used for security (cryptography, passwords) or where money is on the line (loot-boxes, casinos). There are many random number libraries available with different characteristics and you should pick one of those to meet any serious needs.

Parameters
statea pointer to the current random number state, this may not be NULL.
Returns
a random value in the range of [0.0, 1.0).

\threadsafety This function is thread-safe, as long as the state pointer isn't shared between threads.

Since
This function is available since SDL 3.2.0.
See also
SDL_rand_bits_r
SDL_rand_r
SDL_randf

◆ SDL_round()

double SDL_round ( double x)
extern

Round x to the nearest integer.

Rounds x to the nearest integer. Values halfway between integers will be rounded away from zero.

Domain: -INF <= x <= INF

Range: -INF <= y <= INF, y integer

This function operates on double-precision floating point values, use SDL_roundf for single-precision floats. To get the result as an integer type, use SDL_lround.

Parameters
xfloating point value.
Returns
the nearest integer to x.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_roundf
SDL_lround
SDL_floor
SDL_ceil
SDL_trunc

◆ SDL_roundf()

float SDL_roundf ( float x)
extern

Round x to the nearest integer.

Rounds x to the nearest integer. Values halfway between integers will be rounded away from zero.

Domain: -INF <= x <= INF

Range: -INF <= y <= INF, y integer

This function operates on single-precision floating point values, use SDL_round for double-precision floats. To get the result as an integer type, use SDL_lroundf.

Parameters
xfloating point value.
Returns
the nearest integer to x.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_round
SDL_lroundf
SDL_floorf
SDL_ceilf
SDL_truncf

◆ SDL_scalbn()

double SDL_scalbn ( double x,
int n )
extern

Scale x by an integer power of two.

Multiplies x by the nth power of the floating point radix (always 2).

Domain: -INF <= x <= INF, n integer

Range: -INF <= y <= INF

This function operates on double-precision floating point values, use SDL_scalbnf for single-precision floats.

Parameters
xfloating point value to be scaled.
ninteger exponent.
Returns
x * 2^n.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_scalbnf
SDL_pow

◆ SDL_scalbnf()

float SDL_scalbnf ( float x,
int n )
extern

Scale x by an integer power of two.

Multiplies x by the nth power of the floating point radix (always 2).

Domain: -INF <= x <= INF, n integer

Range: -INF <= y <= INF

This function operates on single-precision floating point values, use SDL_scalbn for double-precision floats.

Parameters
xfloating point value to be scaled.
ninteger exponent.
Returns
x * 2^n.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_scalbn
SDL_powf

◆ SDL_setenv_unsafe()

int SDL_setenv_unsafe ( const char * name,
const char * value,
int overwrite )
extern

Set the value of a variable in the environment.

Parameters
namethe name of the variable to set.
valuethe value of the variable to set.
overwrite1 to overwrite the variable if it exists, 0 to return success without setting the variable if it already exists.
Returns
0 on success, -1 on error.

\threadsafety This function is not thread safe, consider using SDL_SetEnvironmentVariable() instead.

Since
This function is available since SDL 3.2.0.
See also
SDL_SetEnvironmentVariable

◆ SDL_SetEnvironmentVariable()

bool SDL_SetEnvironmentVariable ( SDL_Environment * env,
const char * name,
const char * value,
bool overwrite )
extern

Set the value of a variable in the environment.

Parameters
envthe environment to modify.
namethe name of the variable to set.
valuethe value of the variable to set.
overwritetrue to overwrite the variable if it exists, false to return success without setting the variable if it already exists.
Returns
true on success or false on failure; call SDL_GetError() for more information.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_GetEnvironment
SDL_CreateEnvironment
SDL_GetEnvironmentVariable
SDL_GetEnvironmentVariables
SDL_UnsetEnvironmentVariable

◆ SDL_SetMemoryFunctions()

bool SDL_SetMemoryFunctions ( SDL_malloc_func malloc_func,
SDL_calloc_func calloc_func,
SDL_realloc_func realloc_func,
SDL_free_func free_func )
extern

Replace SDL's memory allocation functions with a custom set.

It is not safe to call this function once any allocations have been made, as future calls to SDL_free will use the new allocator, even if they came from an SDL_malloc made with the old one!

If used, usually this needs to be the first call made into the SDL library, if not the very first thing done at program startup time.

Parameters
malloc_funccustom malloc function.
calloc_funccustom calloc function.
realloc_funccustom realloc function.
free_funccustom free function.
Returns
true on success or false on failure; call SDL_GetError() for more information.

\threadsafety It is safe to call this function from any thread, but one should not replace the memory functions once any allocations are made!

Since
This function is available since SDL 3.2.0.
See also
SDL_GetMemoryFunctions
SDL_GetOriginalMemoryFunctions

◆ SDL_sin()

double SDL_sin ( double x)
extern

Compute the sine of x.

Domain: -INF <= x <= INF

Range: -1 <= y <= 1

This function operates on double-precision floating point values, use SDL_sinf for single-precision floats.

This function may use a different approximation across different versions, platforms and configurations. i.e, it can return a different value given the same input on different machines or operating systems, or if SDL is updated.

Parameters
xfloating point value, in radians.
Returns
sine of x.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_sinf
SDL_asin
SDL_cos

◆ SDL_sinf()

float SDL_sinf ( float x)
extern

Compute the sine of x.

Domain: -INF <= x <= INF

Range: -1 <= y <= 1

This function operates on single-precision floating point values, use SDL_sin for double-precision floats.

This function may use a different approximation across different versions, platforms and configurations. i.e, it can return a different value given the same input on different machines or operating systems, or if SDL is updated.

Parameters
xfloating point value, in radians.
Returns
sine of x.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_sin
SDL_asinf
SDL_cosf

◆ SDL_size_add_check_overflow()

SDL_FORCE_INLINE bool SDL_size_add_check_overflow ( size_t a,
size_t b,
size_t * ret )

Add two integers, checking for overflow.

If a + b would overflow, return false.

Otherwise store a + b via ret and return true.

Parameters
athe first addend.
bthe second addend.
reton non-overflow output, stores the addition result, may not be NULL.
Returns
false on overflow, true if result is added without overflow.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

Definition at line 6069 of file SDL_stdinc.h.

6070{
6071 if (b > SDL_SIZE_MAX - a) {
6072 return false;
6073 }
6074 *ret = a + b;
6075 return true;
6076}
#define SDL_SIZE_MAX
Definition SDL_stdinc.h:157

References SDL_SIZE_MAX.

◆ SDL_size_mul_check_overflow()

SDL_FORCE_INLINE bool SDL_size_mul_check_overflow ( size_t a,
size_t b,
size_t * ret )

Multiply two integers, checking for overflow.

If a * b would overflow, return false.

Otherwise store a * b via ret and return true.

Parameters
athe multiplicand.
bthe multiplier.
reton non-overflow output, stores the multiplication result, may not be NULL.
Returns
false on overflow, true if result is multiplied without overflow.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

Definition at line 6030 of file SDL_stdinc.h.

6031{
6032 if (a != 0 && b > SDL_SIZE_MAX / a) {
6033 return false;
6034 }
6035 *ret = a * b;
6036 return true;
6037}

References SDL_SIZE_MAX.

◆ SDL_snprintf()

int SDL_snprintf ( SDL_OUT_Z_CAP(maxlen) char * text,
size_t maxlen,
SDL_PRINTF_FORMAT_STRING const char * fmt,
... )
extern

This works exactly like snprintf() but doesn't require access to a C runtime.

Format a string of up to maxlen-1 bytes, converting each '' item with values provided through variable arguments.

While some C runtimes differ on how to deal with too-large strings, this function null-terminates the output, by treating the null-terminator as part of the maxlen count. Note that if maxlen is zero, however, no bytes will be written at all.

This function returns the number of bytes (not characters) that should be written, excluding the null-terminator character. If this returns a number >= maxlen, it means the output string was truncated. A negative return value means an error occurred.

Referencing the output string's pointer with a format item is undefined behavior.

Parameters
textthe buffer to write the string into. Must not be NULL.
maxlenthe maximum bytes to write, including the null-terminator.
fmta printf-style format string. Must not be NULL.
...a list of values to be used with the format string.
Returns
the number of bytes that should be written, not counting the null-terminator char, or a negative value on error.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_sqrt()

double SDL_sqrt ( double x)
extern

Compute the square root of x.

Domain: 0 <= x <= INF

Range: 0 <= y <= INF

This function operates on double-precision floating point values, use SDL_sqrtf for single-precision floats.

This function may use a different approximation across different versions, platforms and configurations. i.e, it can return a different value given the same input on different machines or operating systems, or if SDL is updated.

Parameters
xfloating point value. Must be greater than or equal to 0.
Returns
square root of x.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_sqrtf

◆ SDL_sqrtf()

float SDL_sqrtf ( float x)
extern

Compute the square root of x.

Domain: 0 <= x <= INF

Range: 0 <= y <= INF

This function operates on single-precision floating point values, use SDL_sqrt for double-precision floats.

This function may use a different approximation across different versions, platforms and configurations. i.e, it can return a different value given the same input on different machines or operating systems, or if SDL is updated.

Parameters
xfloating point value. Must be greater than or equal to 0.
Returns
square root of x.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_sqrt

◆ SDL_srand()

void SDL_srand ( Uint64 seed)
extern

Seeds the pseudo-random number generator.

Reusing the seed number will cause SDL_rand() to repeat the same stream of 'random' numbers.

Parameters
seedthe value to use as a random number seed, or 0 to use SDL_GetPerformanceCounter().

\threadsafety This should be called on the same thread that calls SDL_rand()

Since
This function is available since SDL 3.2.0.
See also
SDL_rand
SDL_rand_bits
SDL_randf

◆ SDL_sscanf()

int SDL_sscanf ( const char * text,
SDL_SCANF_FORMAT_STRING const char * fmt,
... )
extern

This works exactly like sscanf() but doesn't require access to a C runtime.

Scan a string, matching a format string, converting each '' item and storing it to pointers provided through variable arguments.

Parameters
textthe string to scan. Must not be NULL.
fmta printf-style format string. Must not be NULL.
...a list of pointers to values to be filled in with scanned items.
Returns
the number of items that matched the format string.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_StepBackUTF8()

Uint32 SDL_StepBackUTF8 ( const char * start,
const char ** pstr )
extern

Decode a UTF-8 string in reverse, one Unicode codepoint at a time.

This will go to the start of the previous Unicode codepoint in the string, move *pstr to that location and return that codepoint.

If *pstr is already at the start of the string), it will not advance *pstr at all.

Generally this function is called in a loop until it returns zero, adjusting its parameter each iteration.

If an invalid UTF-8 sequence is encountered, this function returns SDL_INVALID_UNICODE_CODEPOINT.

Several things can generate invalid UTF-8 sequences, including overlong encodings, the use of UTF-16 surrogate values, and truncated data. Please refer to RFC3629 for details.

Parameters
starta pointer to the beginning of the UTF-8 string.
pstra pointer to a UTF-8 string pointer to be read and adjusted.
Returns
the previous Unicode codepoint in the string.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_StepUTF8()

Uint32 SDL_StepUTF8 ( const char ** pstr,
size_t * pslen )
extern

Decode a UTF-8 string, one Unicode codepoint at a time.

This will return the first Unicode codepoint in the UTF-8 encoded string in *pstr, and then advance *pstr past any consumed bytes before returning.

It will not access more than *pslen bytes from the string. *pslen will be adjusted, as well, subtracting the number of bytes consumed.

pslen is allowed to be NULL, in which case the string must be NULL-terminated, as the function will blindly read until it sees the NULL char.

if *pslen is zero, it assumes the end of string is reached and returns a zero codepoint regardless of the contents of the string buffer.

If the resulting codepoint is zero (a NULL terminator), or *pslen is zero, it will not advance *pstr or *pslen at all.

Generally this function is called in a loop until it returns zero, adjusting its parameters each iteration.

If an invalid UTF-8 sequence is encountered, this function returns SDL_INVALID_UNICODE_CODEPOINT and advances the string/length by one byte (which is to say, a multibyte sequence might produce several SDL_INVALID_UNICODE_CODEPOINT returns before it syncs to the next valid UTF-8 sequence).

Several things can generate invalid UTF-8 sequences, including overlong encodings, the use of UTF-16 surrogate values, and truncated data. Please refer to RFC3629 for details.

Parameters
pstra pointer to a UTF-8 string pointer to be read and adjusted.
pslena pointer to the number of bytes in the string, to be read and adjusted. NULL is allowed.
Returns
the first Unicode codepoint in the string.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_strcasecmp()

int SDL_strcasecmp ( const char * str1,
const char * str2 )
extern

Compare two null-terminated UTF-8 strings, case-insensitively.

This will work with Unicode strings, using a technique called "case-folding" to handle the vast majority of case-sensitive human languages regardless of system locale. It can deal with expanding values: a German Eszett character can compare against two ASCII 's' chars and be considered a match, for example. A notable exception: it does not handle the Turkish 'i' character; human language is complicated!

Since this handles Unicode, it expects the string to be well-formed UTF-8 and not a null-terminated string of arbitrary bytes. Bytes that are not valid UTF-8 are treated as Unicode character U+FFFD (REPLACEMENT CHARACTER), which is to say two strings of random bits may turn out to match if they convert to the same amount of replacement characters.

Parameters
str1the first string to compare. NULL is not permitted!
str2the second string to compare. NULL is not permitted!
Returns
less than zero if str1 is "less than" str2, greater than zero if str1 is "greater than" str2, and zero if the strings match exactly.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_strcasestr()

char * SDL_strcasestr ( const char * haystack,
const char * needle )
extern

Search a UTF-8 string for the first instance of a specific substring, case-insensitively.

This will work with Unicode strings, using a technique called "case-folding" to handle the vast majority of case-sensitive human languages regardless of system locale. It can deal with expanding values: a German Eszett character can compare against two ASCII 's' chars and be considered a match, for example. A notable exception: it does not handle the Turkish 'i' character; human language is complicated!

Since this handles Unicode, it expects the strings to be well-formed UTF-8 and not a null-terminated string of arbitrary bytes. Bytes that are not valid UTF-8 are treated as Unicode character U+FFFD (REPLACEMENT CHARACTER), which is to say two strings of random bits may turn out to match if they convert to the same amount of replacement characters.

Parameters
haystackthe string to search. Must not be NULL.
needlethe string to search for. Must not be NULL.
Returns
a pointer to the first instance of needle in the string, or NULL if not found.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_strchr()

char * SDL_strchr ( const char * str,
int c )
extern

Search a string for the first instance of a specific byte.

The search ends once it finds the requested byte value, or a null terminator byte to end the string.

Note that this looks for bytes, not characters, so you cannot match against a Unicode codepoint > 255, regardless of character encoding.

Parameters
strthe string to search. Must not be NULL.
cthe byte value to search for.
Returns
a pointer to the first instance of c in the string, or NULL if not found.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_strcmp()

int SDL_strcmp ( const char * str1,
const char * str2 )
extern

Compare two null-terminated UTF-8 strings.

Due to the nature of UTF-8 encoding, this will work with Unicode strings, since effectively this function just compares bytes until it hits a null-terminating character. Also due to the nature of UTF-8, this can be used with SDL_qsort() to put strings in (roughly) alphabetical order.

Parameters
str1the first string to compare. NULL is not permitted!
str2the second string to compare. NULL is not permitted!
Returns
less than zero if str1 is "less than" str2, greater than zero if str1 is "greater than" str2, and zero if the strings match exactly.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_strdup()

SDL_MALLOC char * SDL_strdup ( const char * str)
extern

Allocate a copy of a string.

This allocates enough space for a null-terminated copy of str, using SDL_malloc, and then makes a copy of the string into this space.

The returned string is owned by the caller, and should be passed to SDL_free when no longer needed.

Parameters
strthe string to copy.
Returns
a pointer to the newly-allocated string.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_strlcat()

size_t SDL_strlcat ( SDL_INOUT_Z_CAP(maxlen) char * dst,
const char * src,
size_t maxlen )
extern

Concatenate strings.

This function appends up to maxlen - SDL_strlen(dst) - 1 characters from src to the end of the string in dst, then appends a null terminator.

src and dst must not overlap.

If maxlen - SDL_strlen(dst) - 1 is less than or equal to 0, then dst is unmodified.

Parameters
dstThe destination buffer already containing the first null-terminated string. Must not be NULL and must not overlap with src.
srcThe second null-terminated string. Must not be NULL, and must not overlap with dst.
maxlenThe length (in characters) of the destination buffer.
Returns
the length (in characters, excluding the null terminator) of the string in dst plus the length of src.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_strlcpy

◆ SDL_strlcpy()

size_t SDL_strlcpy ( SDL_OUT_Z_CAP(maxlen) char * dst,
const char * src,
size_t maxlen )
extern

Copy a string.

This function copies up to maxlen - 1 characters from src to dst, then appends a null terminator.

If maxlen is 0, no characters are copied and no null terminator is written.

If you want to copy an UTF-8 string but need to ensure that multi-byte sequences are not truncated, consider using SDL_utf8strlcpy().

Parameters
dstThe destination buffer. Must not be NULL, and must not overlap with src.
srcThe null-terminated string to copy. Must not be NULL, and must not overlap with dst.
maxlenThe length (in characters) of the destination buffer.
Returns
the length (in characters, excluding the null terminator) of src.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_strlcat
SDL_utf8strlcpy

◆ SDL_strlen()

size_t SDL_strlen ( const char * str)
extern

This works exactly like strlen() but doesn't require access to a C runtime.

Counts the bytes in str, excluding the null terminator.

If you need the length of a UTF-8 string, consider using SDL_utf8strlen().

Parameters
strThe null-terminated string to read. Must not be NULL.
Returns
the length (in bytes, excluding the null terminator) of src.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_strnlen
SDL_utf8strlen
SDL_utf8strnlen

Referenced by SDL_AppIterate().

◆ SDL_strlwr()

char * SDL_strlwr ( char * str)
extern

Convert a string to lowercase.

WARNING: Regardless of system locale, this will only convert ASCII values 'A' through 'Z' to lowercase.

This function operates on a null-terminated string of bytes–even if it is malformed UTF-8!–and converts ASCII characters 'A' through 'Z' to their lowercase equivalents in-place, returning the original str pointer.

Parameters
strthe string to convert in-place. Can not be NULL.
Returns
the str pointer passed into this function.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_strupr

◆ SDL_strncasecmp()

int SDL_strncasecmp ( const char * str1,
const char * str2,
size_t maxlen )
extern

Compare two UTF-8 strings, case-insensitively, up to a number of bytes.

This will work with Unicode strings, using a technique called "case-folding" to handle the vast majority of case-sensitive human languages regardless of system locale. It can deal with expanding values: a German Eszett character can compare against two ASCII 's' chars and be considered a match, for example. A notable exception: it does not handle the Turkish 'i' character; human language is complicated!

Since this handles Unicode, it expects the string to be well-formed UTF-8 and not a null-terminated string of arbitrary bytes. Bytes that are not valid UTF-8 are treated as Unicode character U+FFFD (REPLACEMENT CHARACTER), which is to say two strings of random bits may turn out to match if they convert to the same amount of replacement characters.

Note that while this function is intended to be used with UTF-8, maxlen specifies a byte limit! If the limit lands in the middle of a multi-byte UTF-8 sequence, it may convert a portion of the final character to one or more Unicode character U+FFFD (REPLACEMENT CHARACTER) so as not to overflow a buffer.

maxlen specifies a maximum number of bytes to compare; if the strings match to this number of bytes (or both have matched to a null-terminator character before this number of bytes), they will be considered equal.

Parameters
str1the first string to compare. NULL is not permitted!
str2the second string to compare. NULL is not permitted!
maxlenthe maximum number of bytes to compare.
Returns
less than zero if str1 is "less than" str2, greater than zero if str1 is "greater than" str2, and zero if the strings match exactly.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_strncmp()

int SDL_strncmp ( const char * str1,
const char * str2,
size_t maxlen )
extern

Compare two UTF-8 strings up to a number of bytes.

Due to the nature of UTF-8 encoding, this will work with Unicode strings, since effectively this function just compares bytes until it hits a null-terminating character. Also due to the nature of UTF-8, this can be used with SDL_qsort() to put strings in (roughly) alphabetical order.

Note that while this function is intended to be used with UTF-8, it is doing a bytewise comparison, and maxlen specifies a byte limit! If the limit lands in the middle of a multi-byte UTF-8 sequence, it will only compare a portion of the final character.

maxlen specifies a maximum number of bytes to compare; if the strings match to this number of bytes (or both have matched to a null-terminator character before this number of bytes), they will be considered equal.

Parameters
str1the first string to compare. NULL is not permitted!
str2the second string to compare. NULL is not permitted!
maxlenthe maximum number of bytes to compare.
Returns
less than zero if str1 is "less than" str2, greater than zero if str1 is "greater than" str2, and zero if the strings match exactly.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_strndup()

SDL_MALLOC char * SDL_strndup ( const char * str,
size_t maxlen )
extern

Allocate a copy of a string, up to n characters.

This allocates enough space for a null-terminated copy of str, up to maxlen bytes, using SDL_malloc, and then makes a copy of the string into this space.

If the string is longer than maxlen bytes, the returned string will be maxlen bytes long, plus a null-terminator character that isn't included in the count.

The returned string is owned by the caller, and should be passed to SDL_free when no longer needed.

Parameters
strthe string to copy.
maxlenthe maximum length of the copied string, not counting the null-terminator character.
Returns
a pointer to the newly-allocated string.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_strnlen()

size_t SDL_strnlen ( const char * str,
size_t maxlen )
extern

This works exactly like strnlen() but doesn't require access to a C runtime.

Counts up to a maximum of maxlen bytes in str, excluding the null terminator.

If you need the length of a UTF-8 string, consider using SDL_utf8strnlen().

Parameters
strThe null-terminated string to read. Must not be NULL.
maxlenThe maximum amount of bytes to count.
Returns
the length (in bytes, excluding the null terminator) of src but never more than maxlen.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_strlen
SDL_utf8strlen
SDL_utf8strnlen

◆ SDL_strnstr()

char * SDL_strnstr ( const char * haystack,
const char * needle,
size_t maxlen )
extern

Search a string, up to n bytes, for the first instance of a specific substring.

The search ends once it finds the requested substring, or a null terminator byte to end the string, or maxlen bytes have been examined. It is possible to use this function on a string without a null terminator.

Note that this looks for strings of bytes, not characters, so it's legal to search for malformed and incomplete UTF-8 sequences.

Parameters
haystackthe string to search. Must not be NULL.
needlethe string to search for. Must not be NULL.
maxlenthe maximum number of bytes to search in haystack.
Returns
a pointer to the first instance of needle in the string, or NULL if not found.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_strpbrk()

char * SDL_strpbrk ( const char * str,
const char * breakset )
extern

Searches a string for the first occurence of any character contained in a breakset, and returns a pointer from the string to that character.

Parameters
strThe null-terminated string to be searched. Must not be NULL, and must not overlap with breakset.
breaksetA null-terminated string containing the list of characters to look for. Must not be NULL, and must not overlap with str.
Returns
A pointer to the location, in str, of the first occurence of a character present in the breakset, or NULL if none is found.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_strrchr()

char * SDL_strrchr ( const char * str,
int c )
extern

Search a string for the last instance of a specific byte.

The search must go until it finds a null terminator byte to end the string.

Note that this looks for bytes, not characters, so you cannot match against a Unicode codepoint > 255, regardless of character encoding.

Parameters
strthe string to search. Must not be NULL.
cthe byte value to search for.
Returns
a pointer to the last instance of c in the string, or NULL if not found.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_strrev()

char * SDL_strrev ( char * str)
extern

Reverse a string's contents.

This reverses a null-terminated string in-place. Only the content of the string is reversed; the null-terminator character remains at the end of the reversed string.

WARNING: This function reverses the bytes of the string, not the codepoints. If str is a UTF-8 string with Unicode codepoints > 127, this will ruin the string data. You should only use this function on strings that are completely comprised of low ASCII characters.

Parameters
strthe string to reverse.
Returns
str.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_strstr()

char * SDL_strstr ( const char * haystack,
const char * needle )
extern

Search a string for the first instance of a specific substring.

The search ends once it finds the requested substring, or a null terminator byte to end the string.

Note that this looks for strings of bytes, not characters, so it's legal to search for malformed and incomplete UTF-8 sequences.

Parameters
haystackthe string to search. Must not be NULL.
needlethe string to search for. Must not be NULL.
Returns
a pointer to the first instance of needle in the string, or NULL if not found.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_strtod()

double SDL_strtod ( const char * str,
char ** endp )
extern

Parse a double from a string.

This function makes fewer guarantees than the C runtime strtod:

  • Only decimal notation is guaranteed to be supported. The handling of scientific and hexadecimal notation is unspecified.
  • Whether or not INF and NAN can be parsed is unspecified.
  • The precision of the result is unspecified.
Parameters
strthe null-terminated string to read. Must not be NULL.
endpif not NULL, the address of the first invalid character (i.e. the next character after the parsed number) will be written to this pointer.
Returns
the parsed double, or 0 if no number could be parsed.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_atoi
SDL_atof
SDL_strtol
SDL_strtoll
SDL_strtoul
SDL_strtoull

◆ SDL_strtok_r()

char * SDL_strtok_r ( char * str,
const char * delim,
char ** saveptr )
extern

This works exactly like strtok_r() but doesn't require access to a C runtime.

Break a string up into a series of tokens.

To start tokenizing a new string, str should be the non-NULL address of the string to start tokenizing. Future calls to get the next token from the same string should specify a NULL.

Note that this function will overwrite pieces of str with null chars to split it into tokens. This function cannot be used with const/read-only strings!

saveptr just needs to point to a char * that can be overwritten; SDL will use this to save tokenizing state between calls. It is initialized if str is non-NULL, and used to resume tokenizing when str is NULL.

Parameters
strthe string to tokenize, or NULL to continue tokenizing.
delimthe delimiter string that separates tokens.
saveptrpointer to a char *, used for ongoing state.
Returns
A pointer to the next token, or NULL if no tokens remain.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_strtol()

long SDL_strtol ( const char * str,
char ** endp,
int base )
extern

Parse a long from a string.

If str starts with whitespace, then those whitespace characters are skipped before attempting to parse the number.

If the parsed number does not fit inside a long, the result is clamped to the minimum and maximum representable long values.

Parameters
strThe null-terminated string to read. Must not be NULL.
endpIf not NULL, the address of the first invalid character (i.e. the next character after the parsed number) will be written to this pointer.
baseThe base of the integer to read. Supported values are 0 and 2 to 36 inclusive. If 0, the base will be inferred from the number's prefix (0x for hexadecimal, 0 for octal, decimal otherwise).
Returns
the parsed long, or 0 if no number could be parsed.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_atoi
SDL_atof
SDL_strtoul
SDL_strtoll
SDL_strtoull
SDL_strtod
SDL_ltoa
SDL_wcstol

◆ SDL_strtoll()

long long SDL_strtoll ( const char * str,
char ** endp,
int base )
extern

Parse a long long from a string.

If str starts with whitespace, then those whitespace characters are skipped before attempting to parse the number.

If the parsed number does not fit inside a long long, the result is clamped to the minimum and maximum representable long long values.

Parameters
strThe null-terminated string to read. Must not be NULL.
endpIf not NULL, the address of the first invalid character (i.e. the next character after the parsed number) will be written to this pointer.
baseThe base of the integer to read. Supported values are 0 and 2 to 36 inclusive. If 0, the base will be inferred from the number's prefix (0x for hexadecimal, 0 for octal, decimal otherwise).
Returns
the parsed long long, or 0 if no number could be parsed.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_atoi
SDL_atof
SDL_strtol
SDL_strtoul
SDL_strtoull
SDL_strtod
SDL_lltoa

◆ SDL_strtoul()

unsigned long SDL_strtoul ( const char * str,
char ** endp,
int base )
extern

Parse an unsigned long from a string.

If str starts with whitespace, then those whitespace characters are skipped before attempting to parse the number.

If the parsed number does not fit inside an unsigned long, the result is clamped to the maximum representable unsigned long value.

Parameters
strThe null-terminated string to read. Must not be NULL.
endpIf not NULL, the address of the first invalid character (i.e. the next character after the parsed number) will be written to this pointer.
baseThe base of the integer to read. Supported values are 0 and 2 to 36 inclusive. If 0, the base will be inferred from the number's prefix (0x for hexadecimal, 0 for octal, decimal otherwise).
Returns
the parsed unsigned long, or 0 if no number could be parsed.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_atoi
SDL_atof
SDL_strtol
SDL_strtoll
SDL_strtoull
SDL_strtod
SDL_ultoa

◆ SDL_strtoull()

unsigned long long SDL_strtoull ( const char * str,
char ** endp,
int base )
extern

Parse an unsigned long long from a string.

If str starts with whitespace, then those whitespace characters are skipped before attempting to parse the number.

If the parsed number does not fit inside an unsigned long long, the result is clamped to the maximum representable unsigned long long value.

Parameters
strThe null-terminated string to read. Must not be NULL.
endpIf not NULL, the address of the first invalid character (i.e. the next character after the parsed number) will be written to this pointer.
baseThe base of the integer to read. Supported values are 0 and 2 to 36 inclusive. If 0, the base will be inferred from the number's prefix (0x for hexadecimal, 0 for octal, decimal otherwise).
Returns
the parsed unsigned long long, or 0 if no number could be parsed.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_atoi
SDL_atof
SDL_strtol
SDL_strtoll
SDL_strtoul
SDL_strtod
SDL_ulltoa

◆ SDL_strupr()

char * SDL_strupr ( char * str)
extern

Convert a string to uppercase.

WARNING: Regardless of system locale, this will only convert ASCII values 'A' through 'Z' to uppercase.

This function operates on a null-terminated string of bytes–even if it is malformed UTF-8!–and converts ASCII characters 'a' through 'z' to their uppercase equivalents in-place, returning the original str pointer.

Parameters
strthe string to convert in-place. Can not be NULL.
Returns
the str pointer passed into this function.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_strlwr

◆ SDL_swprintf()

int SDL_swprintf ( SDL_OUT_Z_CAP(maxlen) wchar_t * text,
size_t maxlen,
SDL_PRINTF_FORMAT_STRING const wchar_t * fmt,
... )
extern

This works exactly like swprintf() but doesn't require access to a C runtime.

Format a wide string of up to maxlen-1 wchar_t values, converting each '' item with values provided through variable arguments.

While some C runtimes differ on how to deal with too-large strings, this function null-terminates the output, by treating the null-terminator as part of the maxlen count. Note that if maxlen is zero, however, no wide characters will be written at all.

This function returns the number of wide characters (not codepoints) that should be written, excluding the null-terminator character. If this returns a number >= maxlen, it means the output string was truncated. A negative return value means an error occurred.

Referencing the output string's pointer with a format item is undefined behavior.

Parameters
textthe buffer to write the wide string into. Must not be NULL.
maxlenthe maximum wchar_t values to write, including the null-terminator.
fmta printf-style format string. Must not be NULL.
...a list of values to be used with the format string.
Returns
the number of wide characters that should be written, not counting the null-terminator char, or a negative value on error.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_tan()

double SDL_tan ( double x)
extern

Compute the tangent of x.

Domain: -INF <= x <= INF

Range: -INF <= y <= INF

This function operates on double-precision floating point values, use SDL_tanf for single-precision floats.

This function may use a different approximation across different versions, platforms and configurations. i.e, it can return a different value given the same input on different machines or operating systems, or if SDL is updated.

Parameters
xfloating point value, in radians.
Returns
tangent of x.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_tanf
SDL_sin
SDL_cos
SDL_atan
SDL_atan2

◆ SDL_tanf()

float SDL_tanf ( float x)
extern

Compute the tangent of x.

Domain: -INF <= x <= INF

Range: -INF <= y <= INF

This function operates on single-precision floating point values, use SDL_tan for double-precision floats.

This function may use a different approximation across different versions, platforms and configurations. i.e, it can return a different value given the same input on different machines or operating systems, or if SDL is updated.

Parameters
xfloating point value, in radians.
Returns
tangent of x.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_tan
SDL_sinf
SDL_cosf
SDL_atanf
SDL_atan2f

◆ SDL_tolower()

int SDL_tolower ( int x)
extern

Convert low-ASCII English letters to lowercase.

WARNING: Regardless of system locale, this will only convert ASCII values 'A' through 'Z' to lowercase.

This function returns the lowercase equivalent of x. If a character cannot be converted, or is already lowercase, this function returns x.

Parameters
xcharacter value to check.
Returns
lowercase version of x, or x if no conversion available.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_toupper()

int SDL_toupper ( int x)
extern

Convert low-ASCII English letters to uppercase.

WARNING: Regardless of system locale, this will only convert ASCII values 'a' through 'z' to uppercase.

This function returns the uppercase equivalent of x. If a character cannot be converted, or is already uppercase, this function returns x.

Parameters
xcharacter value to check.
Returns
capitalized version of x, or x if no conversion available.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_trunc()

double SDL_trunc ( double x)
extern

Truncate x to an integer.

Rounds x to the next closest integer to 0. This is equivalent to removing the fractional part of x, leaving only the integer part.

Domain: -INF <= x <= INF

Range: -INF <= y <= INF, y integer

This function operates on double-precision floating point values, use SDL_truncf for single-precision floats.

Parameters
xfloating point value.
Returns
x truncated to an integer.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_truncf
SDL_fmod
SDL_ceil
SDL_floor
SDL_round
SDL_lround

◆ SDL_truncf()

float SDL_truncf ( float x)
extern

Truncate x to an integer.

Rounds x to the next closest integer to 0. This is equivalent to removing the fractional part of x, leaving only the integer part.

Domain: -INF <= x <= INF

Range: -INF <= y <= INF, y integer

This function operates on single-precision floating point values, use SDL_trunc for double-precision floats.

Parameters
xfloating point value.
Returns
x truncated to an integer.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_trunc
SDL_fmodf
SDL_ceilf
SDL_floorf
SDL_roundf
SDL_lroundf

◆ SDL_UCS4ToUTF8()

char * SDL_UCS4ToUTF8 ( Uint32 codepoint,
char * dst )
extern

Convert a single Unicode codepoint to UTF-8.

The buffer pointed to by dst must be at least 4 bytes long, as this function may generate between 1 and 4 bytes of output.

This function returns the first byte after the newly-written UTF-8 sequence, which is useful for encoding multiple codepoints in a loop, or knowing where to write a NULL-terminator character to end the string (in either case, plan to have a buffer of more than 4 bytes!).

If codepoint is an invalid value (outside the Unicode range, or a UTF-16 surrogate value, etc), this will use U+FFFD (REPLACEMENT CHARACTER) for the codepoint instead, and not set an error.

If dst is NULL, this returns NULL immediately without writing to the pointer and without setting an error.

Parameters
codepointa Unicode codepoint to convert to UTF-8.
dstthe location to write the encoded UTF-8. Must point to at least 4 bytes!
Returns
the first byte past the newly-written UTF-8 sequence.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_uitoa()

char * SDL_uitoa ( unsigned int value,
char * str,
int radix )
extern

Convert an unsigned integer into a string.

This requires a radix to specified for string format. Specifying 10 produces a decimal number, 16 hexidecimal, etc. Must be in the range of 2 to 36.

Note that this function will overflow a buffer if str is not large enough to hold the output! It may be safer to use SDL_snprintf to clamp output, or SDL_asprintf to allocate a buffer. Otherwise, it doesn't hurt to allocate much more space than you expect to use (and don't forget null terminator bytes, etc).

Parameters
valuethe unsigned integer to convert.
strthe buffer to write the string into.
radixthe radix to use for string generation.
Returns
str.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_itoa
SDL_ultoa
SDL_ulltoa

◆ SDL_ulltoa()

char * SDL_ulltoa ( unsigned long long value,
char * str,
int radix )
extern

Convert an unsigned long long integer into a string.

This requires a radix to specified for string format. Specifying 10 produces a decimal number, 16 hexidecimal, etc. Must be in the range of 2 to 36.

Note that this function will overflow a buffer if str is not large enough to hold the output! It may be safer to use SDL_snprintf to clamp output, or SDL_asprintf to allocate a buffer. Otherwise, it doesn't hurt to allocate much more space than you expect to use (and don't forget null terminator bytes, etc).

Parameters
valuethe unsigned long long integer to convert.
strthe buffer to write the string into.
radixthe radix to use for string generation.
Returns
str.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_lltoa
SDL_uitoa
SDL_ultoa

◆ SDL_ultoa()

char * SDL_ultoa ( unsigned long value,
char * str,
int radix )
extern

Convert an unsigned long integer into a string.

This requires a radix to specified for string format. Specifying 10 produces a decimal number, 16 hexidecimal, etc. Must be in the range of 2 to 36.

Note that this function will overflow a buffer if str is not large enough to hold the output! It may be safer to use SDL_snprintf to clamp output, or SDL_asprintf to allocate a buffer. Otherwise, it doesn't hurt to allocate much more space than you expect to use (and don't forget null terminator bytes, etc).

Parameters
valuethe unsigned long integer to convert.
strthe buffer to write the string into.
radixthe radix to use for string generation.
Returns
str.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_ltoa
SDL_uitoa
SDL_ulltoa

◆ SDL_unsetenv_unsafe()

int SDL_unsetenv_unsafe ( const char * name)
extern

Clear a variable from the environment.

Parameters
namethe name of the variable to unset.
Returns
0 on success, -1 on error.

\threadsafety This function is not thread safe, consider using SDL_UnsetEnvironmentVariable() instead.

Since
This function is available since SDL 3.2.0.
See also
SDL_UnsetEnvironmentVariable

◆ SDL_UnsetEnvironmentVariable()

bool SDL_UnsetEnvironmentVariable ( SDL_Environment * env,
const char * name )
extern

Clear a variable from the environment.

Parameters
envthe environment to modify.
namethe name of the variable to unset.
Returns
true on success or false on failure; call SDL_GetError() for more information.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_GetEnvironment
SDL_CreateEnvironment
SDL_GetEnvironmentVariable
SDL_GetEnvironmentVariables
SDL_SetEnvironmentVariable
SDL_UnsetEnvironmentVariable

◆ SDL_utf8strlcpy()

size_t SDL_utf8strlcpy ( SDL_OUT_Z_CAP(dst_bytes) char * dst,
const char * src,
size_t dst_bytes )
extern

Copy an UTF-8 string.

This function copies up to dst_bytes - 1 bytes from src to dst while also ensuring that the string written to dst does not end in a truncated multi-byte sequence. Finally, it appends a null terminator.

src and dst must not overlap.

Note that unlike SDL_strlcpy(), this function returns the number of bytes written, not the length of src.

Parameters
dstThe destination buffer. Must not be NULL, and must not overlap with src.
srcThe null-terminated UTF-8 string to copy. Must not be NULL, and must not overlap with dst.
dst_bytesThe length (in bytes) of the destination buffer. Must not be 0.
Returns
the number of bytes written, excluding the null terminator.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_strlcpy

◆ SDL_utf8strlen()

size_t SDL_utf8strlen ( const char * str)
extern

Count the number of codepoints in a UTF-8 string.

Counts the codepoints, not bytes, in str, excluding the null terminator.

If you need to count the bytes in a string instead, consider using SDL_strlen().

Since this handles Unicode, it expects the strings to be well-formed UTF-8 and not a null-terminated string of arbitrary bytes. Bytes that are not valid UTF-8 are treated as Unicode character U+FFFD (REPLACEMENT CHARACTER), so a malformed or incomplete UTF-8 sequence might increase the count by several replacement characters.

Parameters
strThe null-terminated UTF-8 string to read. Must not be NULL.
Returns
The length (in codepoints, excluding the null terminator) of src.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_utf8strnlen
SDL_strlen

◆ SDL_utf8strnlen()

size_t SDL_utf8strnlen ( const char * str,
size_t bytes )
extern

Count the number of codepoints in a UTF-8 string, up to n bytes.

Counts the codepoints, not bytes, in str, excluding the null terminator.

If you need to count the bytes in a string instead, consider using SDL_strnlen().

The counting stops at bytes bytes (not codepoints!). This seems counterintuitive, but makes it easy to express the total size of the string's buffer.

Since this handles Unicode, it expects the strings to be well-formed UTF-8 and not a null-terminated string of arbitrary bytes. Bytes that are not valid UTF-8 are treated as Unicode character U+FFFD (REPLACEMENT CHARACTER), so a malformed or incomplete UTF-8 sequence might increase the count by several replacement characters.

Parameters
strThe null-terminated UTF-8 string to read. Must not be NULL.
bytesThe maximum amount of bytes to count.
Returns
The length (in codepoints, excluding the null terminator) of src but never more than maxlen.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_utf8strlen
SDL_strnlen

◆ SDL_vasprintf()

int SDL_vasprintf ( char ** strp,
SDL_PRINTF_FORMAT_STRING const char * fmt,
va_list ap )
extern

This works exactly like vasprintf() but doesn't require access to a C runtime.

Functions identically to SDL_asprintf(), except it takes a va_list instead of using ... variable arguments.

Parameters
strpon output, is set to the new string. Must not be NULL.
fmta printf-style format string. Must not be NULL.
apa va_list values to be used with the format string.
Returns
the number of bytes in the newly-allocated string, not counting the null-terminator char, or a negative value on error.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_vsnprintf()

int SDL_vsnprintf ( SDL_OUT_Z_CAP(maxlen) char * text,
size_t maxlen,
SDL_PRINTF_FORMAT_STRING const char * fmt,
va_list ap )
extern

This works exactly like vsnprintf() but doesn't require access to a C runtime.

Functions identically to SDL_snprintf(), except it takes a va_list instead of using ... variable arguments.

Parameters
textthe buffer to write the string into. Must not be NULL.
maxlenthe maximum bytes to write, including the null-terminator.
fmta printf-style format string. Must not be NULL.
apa va_list values to be used with the format string.
Returns
the number of bytes that should be written, not counting the null-terminator char, or a negative value on error.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_vsscanf()

int SDL_vsscanf ( const char * text,
SDL_SCANF_FORMAT_STRING const char * fmt,
va_list ap )
extern

This works exactly like vsscanf() but doesn't require access to a C runtime.

Functions identically to SDL_sscanf(), except it takes a va_list instead of using ... variable arguments.

Parameters
textthe string to scan. Must not be NULL.
fmta printf-style format string. Must not be NULL.
apa va_list of pointers to values to be filled in with scanned items.
Returns
the number of items that matched the format string.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_vswprintf()

int SDL_vswprintf ( SDL_OUT_Z_CAP(maxlen) wchar_t * text,
size_t maxlen,
SDL_PRINTF_FORMAT_STRING const wchar_t * fmt,
va_list ap )
extern

This works exactly like vswprintf() but doesn't require access to a C runtime.

Functions identically to SDL_swprintf(), except it takes a va_list instead of using ... variable arguments.

Parameters
textthe buffer to write the string into. Must not be NULL.
maxlenthe maximum wide characters to write, including the null-terminator.
fmta printf-style format wide string. Must not be NULL.
apa va_list values to be used with the format string.
Returns
the number of wide characters that should be written, not counting the null-terminator char, or a negative value on error.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_wcscasecmp()

int SDL_wcscasecmp ( const wchar_t * str1,
const wchar_t * str2 )
extern

Compare two null-terminated wide strings, case-insensitively.

This will work with Unicode strings, using a technique called "case-folding" to handle the vast majority of case-sensitive human languages regardless of system locale. It can deal with expanding values: a German Eszett character can compare against two ASCII 's' chars and be considered a match, for example. A notable exception: it does not handle the Turkish 'i' character; human language is complicated!

Depending on your platform, "wchar_t" might be 2 bytes, and expected to be UTF-16 encoded (like Windows), or 4 bytes in UTF-32 format. Since this handles Unicode, it expects the string to be well-formed and not a null-terminated string of arbitrary bytes. Characters that are not valid UTF-16 (or UTF-32) are treated as Unicode character U+FFFD (REPLACEMENT CHARACTER), which is to say two strings of random bits may turn out to match if they convert to the same amount of replacement characters.

Parameters
str1the first string to compare. NULL is not permitted!
str2the second string to compare. NULL is not permitted!
Returns
less than zero if str1 is "less than" str2, greater than zero if str1 is "greater than" str2, and zero if the strings match exactly.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_wcscmp()

int SDL_wcscmp ( const wchar_t * str1,
const wchar_t * str2 )
extern

Compare two null-terminated wide strings.

This only compares wchar_t values until it hits a null-terminating character; it does not care if the string is well-formed UTF-16 (or UTF-32, depending on your platform's wchar_t size), or uses valid Unicode values.

Parameters
str1the first string to compare. NULL is not permitted!
str2the second string to compare. NULL is not permitted!
Returns
less than zero if str1 is "less than" str2, greater than zero if str1 is "greater than" str2, and zero if the strings match exactly.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_wcsdup()

wchar_t * SDL_wcsdup ( const wchar_t * wstr)
extern

Allocate a copy of a wide string.

This allocates enough space for a null-terminated copy of wstr, using SDL_malloc, and then makes a copy of the string into this space.

The returned string is owned by the caller, and should be passed to SDL_free when no longer needed.

Parameters
wstrthe string to copy.
Returns
a pointer to the newly-allocated wide string.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_wcslcat()

size_t SDL_wcslcat ( SDL_INOUT_Z_CAP(maxlen) wchar_t * dst,
const wchar_t * src,
size_t maxlen )
extern

Concatenate wide strings.

This function appends up to maxlen - SDL_wcslen(dst) - 1 wide characters from src to the end of the wide string in dst, then appends a null terminator.

src and dst must not overlap.

If maxlen - SDL_wcslen(dst) - 1 is less than or equal to 0, then dst is unmodified.

Parameters
dstThe destination buffer already containing the first null-terminated wide string. Must not be NULL and must not overlap with src.
srcThe second null-terminated wide string. Must not be NULL, and must not overlap with dst.
maxlenThe length (in wide characters) of the destination buffer.
Returns
the length (in wide characters, excluding the null terminator) of the string in dst plus the length of src.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_wcslcpy

◆ SDL_wcslcpy()

size_t SDL_wcslcpy ( SDL_OUT_Z_CAP(maxlen) wchar_t * dst,
const wchar_t * src,
size_t maxlen )
extern

Copy a wide string.

This function copies maxlen - 1 wide characters from src to dst, then appends a null terminator.

src and dst must not overlap.

If maxlen is 0, no wide characters are copied and no null terminator is written.

Parameters
dstThe destination buffer. Must not be NULL, and must not overlap with src.
srcThe null-terminated wide string to copy. Must not be NULL, and must not overlap with dst.
maxlenThe length (in wide characters) of the destination buffer.
Returns
the length (in wide characters, excluding the null terminator) of src.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_wcslcat

◆ SDL_wcslen()

size_t SDL_wcslen ( const wchar_t * wstr)
extern

This works exactly like wcslen() but doesn't require access to a C runtime.

Counts the number of wchar_t values in wstr, excluding the null terminator.

Like SDL_strlen only counts bytes and not codepoints in a UTF-8 string, this counts wchar_t values in a string, even if the string's encoding is of variable width, like UTF-16.

Also be aware that wchar_t is different sizes on different platforms (4 bytes on Linux, 2 on Windows, etc).

Parameters
wstrThe null-terminated wide string to read. Must not be NULL.
Returns
the length (in wchar_t values, excluding the null terminator) of wstr.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_wcsnlen
SDL_utf8strlen
SDL_utf8strnlen

◆ SDL_wcsncasecmp()

int SDL_wcsncasecmp ( const wchar_t * str1,
const wchar_t * str2,
size_t maxlen )
extern

Compare two wide strings, case-insensitively, up to a number of wchar_t.

This will work with Unicode strings, using a technique called "case-folding" to handle the vast majority of case-sensitive human languages regardless of system locale. It can deal with expanding values: a German Eszett character can compare against two ASCII 's' chars and be considered a match, for example. A notable exception: it does not handle the Turkish 'i' character; human language is complicated!

Depending on your platform, "wchar_t" might be 2 bytes, and expected to be UTF-16 encoded (like Windows), or 4 bytes in UTF-32 format. Since this handles Unicode, it expects the string to be well-formed and not a null-terminated string of arbitrary bytes. Characters that are not valid UTF-16 (or UTF-32) are treated as Unicode character U+FFFD (REPLACEMENT CHARACTER), which is to say two strings of random bits may turn out to match if they convert to the same amount of replacement characters.

Note that while this function might deal with variable-sized characters, maxlen specifies a wchar limit! If the limit lands in the middle of a multi-byte UTF-16 sequence, it may convert a portion of the final character to one or more Unicode character U+FFFD (REPLACEMENT CHARACTER) so as not to overflow a buffer.

maxlen specifies a maximum number of wchar_t values to compare; if the strings match to this number of wchar_t (or both have matched to a null-terminator character before this number of bytes), they will be considered equal.

Parameters
str1the first string to compare. NULL is not permitted!
str2the second string to compare. NULL is not permitted!
maxlenthe maximum number of wchar_t values to compare.
Returns
less than zero if str1 is "less than" str2, greater than zero if str1 is "greater than" str2, and zero if the strings match exactly.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_wcsncmp()

int SDL_wcsncmp ( const wchar_t * str1,
const wchar_t * str2,
size_t maxlen )
extern

Compare two wide strings up to a number of wchar_t values.

This only compares wchar_t values; it does not care if the string is well-formed UTF-16 (or UTF-32, depending on your platform's wchar_t size), or uses valid Unicode values.

Note that while this function is intended to be used with UTF-16 (or UTF-32, depending on your platform's definition of wchar_t), it is comparing raw wchar_t values and not Unicode codepoints: maxlen specifies a wchar_t limit! If the limit lands in the middle of a multi-wchar UTF-16 sequence, it will only compare a portion of the final character.

maxlen specifies a maximum number of wchar_t to compare; if the strings match to this number of wide chars (or both have matched to a null-terminator character before this count), they will be considered equal.

Parameters
str1the first string to compare. NULL is not permitted!
str2the second string to compare. NULL is not permitted!
maxlenthe maximum number of wchar_t to compare.
Returns
less than zero if str1 is "less than" str2, greater than zero if str1 is "greater than" str2, and zero if the strings match exactly.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_wcsnlen()

size_t SDL_wcsnlen ( const wchar_t * wstr,
size_t maxlen )
extern

This works exactly like wcsnlen() but doesn't require access to a C runtime.

Counts up to a maximum of maxlen wchar_t values in wstr, excluding the null terminator.

Like SDL_strnlen only counts bytes and not codepoints in a UTF-8 string, this counts wchar_t values in a string, even if the string's encoding is of variable width, like UTF-16.

Also be aware that wchar_t is different sizes on different platforms (4 bytes on Linux, 2 on Windows, etc).

Also, maxlen is a count of wide characters, not bytes!

Parameters
wstrThe null-terminated wide string to read. Must not be NULL.
maxlenThe maximum amount of wide characters to count.
Returns
the length (in wide characters, excluding the null terminator) of wstr but never more than maxlen.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_wcslen
SDL_utf8strlen
SDL_utf8strnlen

◆ SDL_wcsnstr()

wchar_t * SDL_wcsnstr ( const wchar_t * haystack,
const wchar_t * needle,
size_t maxlen )
extern

Search a wide string, up to n wide chars, for the first instance of a specific substring.

The search ends once it finds the requested substring, or a null terminator value to end the string, or maxlen wide character have been examined. It is possible to use this function on a wide string without a null terminator.

Note that this looks for strings of wide characters, not codepoints, so it's legal to search for malformed and incomplete UTF-16 sequences.

Parameters
haystackthe wide string to search. Must not be NULL.
needlethe wide string to search for. Must not be NULL.
maxlenthe maximum number of wide characters to search in haystack.
Returns
a pointer to the first instance of needle in the string, or NULL if not found.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_wcsstr()

wchar_t * SDL_wcsstr ( const wchar_t * haystack,
const wchar_t * needle )
extern

Search a wide string for the first instance of a specific substring.

The search ends once it finds the requested substring, or a null terminator byte to end the string.

Note that this looks for strings of wide characters, not codepoints, so it's legal to search for malformed and incomplete UTF-16 sequences.

Parameters
haystackthe wide string to search. Must not be NULL.
needlethe wide string to search for. Must not be NULL.
Returns
a pointer to the first instance of needle in the string, or NULL if not found.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.

◆ SDL_wcstol()

long SDL_wcstol ( const wchar_t * str,
wchar_t ** endp,
int base )
extern

Parse a long from a wide string.

If str starts with whitespace, then those whitespace characters are skipped before attempting to parse the number.

If the parsed number does not fit inside a long, the result is clamped to the minimum and maximum representable long values.

Parameters
strThe null-terminated wide string to read. Must not be NULL.
endpIf not NULL, the address of the first invalid wide character (i.e. the next character after the parsed number) will be written to this pointer.
baseThe base of the integer to read. Supported values are 0 and 2 to 36 inclusive. If 0, the base will be inferred from the number's prefix (0x for hexadecimal, 0 for octal, decimal otherwise).
Returns
the parsed long, or 0 if no number could be parsed.

\threadsafety It is safe to call this function from any thread.

Since
This function is available since SDL 3.2.0.
See also
SDL_strtol

Variable Documentation

◆ size

size_t size

Definition at line 1338 of file SDL_stdinc.h.