From 6aaedb813fa11ba0679c3051bc2eb28646b9506c Mon Sep 17 00:00:00 2001 From: 3gg <3gg@shellblade.net> Date: Sat, 30 Aug 2025 16:53:58 -0700 Subject: Update to SDL3 --- src/contrib/SDL-3.2.20/include/SDL3/SDL_bits.h | 147 +++++++++++++++++++++++++ 1 file changed, 147 insertions(+) create mode 100644 src/contrib/SDL-3.2.20/include/SDL3/SDL_bits.h (limited to 'src/contrib/SDL-3.2.20/include/SDL3/SDL_bits.h') diff --git a/src/contrib/SDL-3.2.20/include/SDL3/SDL_bits.h b/src/contrib/SDL-3.2.20/include/SDL3/SDL_bits.h new file mode 100644 index 0000000..7435ce6 --- /dev/null +++ b/src/contrib/SDL-3.2.20/include/SDL3/SDL_bits.h @@ -0,0 +1,147 @@ +/* + Simple DirectMedia Layer + Copyright (C) 1997-2025 Sam Lantinga + + This software is provided 'as-is', without any express or implied + warranty. In no event will the authors be held liable for any damages + arising from the use of this software. + + Permission is granted to anyone to use this software for any purpose, + including commercial applications, and to alter it and redistribute it + freely, subject to the following restrictions: + + 1. The origin of this software must not be misrepresented; you must not + claim that you wrote the original software. If you use this software + in a product, an acknowledgment in the product documentation would be + appreciated but is not required. + 2. Altered source versions must be plainly marked as such, and must not be + misrepresented as being the original software. + 3. This notice may not be removed or altered from any source distribution. +*/ + +/** + * # CategoryBits + * + * Functions for fiddling with bits and bitmasks. + */ + +#ifndef SDL_bits_h_ +#define SDL_bits_h_ + +#include + +#include +/* Set up for C function definitions, even when using C++ */ +#ifdef __cplusplus +extern "C" { +#endif + +#if defined(__WATCOMC__) && defined(__386__) +extern __inline int _SDL_bsr_watcom(Uint32); +#pragma aux _SDL_bsr_watcom = \ + "bsr eax, eax" \ + parm [eax] nomemory \ + value [eax] \ + modify exact [eax] nomemory; +#endif + +/** + * Get the index of the most significant (set) bit in a 32-bit number. + * + * Result is undefined when called with 0. This operation can also be stated + * as "count leading zeroes" and "log base 2". + * + * Note that this is a forced-inline function in a header, and not a public + * API function available in the SDL library (which is to say, the code is + * embedded in the calling program and the linker and dynamic loader will not + * be able to find this function inside SDL itself). + * + * \param x the 32-bit value to examine. + * \returns the index of the most significant bit, or -1 if the value is 0. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + */ +SDL_FORCE_INLINE int SDL_MostSignificantBitIndex32(Uint32 x) +{ +#if defined(__GNUC__) && (__GNUC__ >= 4 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)) + /* Count Leading Zeroes builtin in GCC. + * http://gcc.gnu.org/onlinedocs/gcc-4.3.4/gcc/Other-Builtins.html + */ + if (x == 0) { + return -1; + } + return 31 - __builtin_clz(x); +#elif defined(__WATCOMC__) && defined(__386__) + if (x == 0) { + return -1; + } + return _SDL_bsr_watcom(x); +#elif defined(_MSC_VER) && _MSC_VER >= 1400 + unsigned long index; + if (_BitScanReverse(&index, x)) { + return (int)index; + } + return -1; +#else + /* Based off of Bit Twiddling Hacks by Sean Eron Anderson + * , released in the public domain. + * http://graphics.stanford.edu/~seander/bithacks.html#IntegerLog + */ + const Uint32 b[] = {0x2, 0xC, 0xF0, 0xFF00, 0xFFFF0000}; + const int S[] = {1, 2, 4, 8, 16}; + + int msbIndex = 0; + int i; + + if (x == 0) { + return -1; + } + + for (i = 4; i >= 0; i--) + { + if (x & b[i]) + { + x >>= S[i]; + msbIndex |= S[i]; + } + } + + return msbIndex; +#endif +} + +/** + * Determine if a unsigned 32-bit value has exactly one bit set. + * + * If there are no bits set (`x` is zero), or more than one bit set, this + * returns false. If any one bit is exclusively set, this returns true. + * + * Note that this is a forced-inline function in a header, and not a public + * API function available in the SDL library (which is to say, the code is + * embedded in the calling program and the linker and dynamic loader will not + * be able to find this function inside SDL itself). + * + * \param x the 32-bit value to examine. + * \returns true if exactly one bit is set in `x`, false otherwise. + * + * \threadsafety It is safe to call this function from any thread. + * + * \since This function is available since SDL 3.2.0. + */ +SDL_FORCE_INLINE bool SDL_HasExactlyOneBitSet32(Uint32 x) +{ + if (x && !(x & (x - 1))) { + return true; + } + return false; +} + +/* Ends C function definitions when using C++ */ +#ifdef __cplusplus +} +#endif +#include + +#endif /* SDL_bits_h_ */ -- cgit v1.2.3