X-Git-Url: http://git.xonotic.org/?p=xonotic%2Fdarkplaces.git;a=blobdiff_plain;f=packages%2Fsdl2.nuget.2.0.22%2Fbuild%2Fnative%2Finclude%2FSDL_bits.h;fp=packages%2Fsdl2.nuget.2.0.22%2Fbuild%2Fnative%2Finclude%2FSDL_bits.h;h=22cb853140ddf45249fec2e541faaae608ac2f15;hp=0000000000000000000000000000000000000000;hb=8cb32a53667039bd9225005dc0f2d15460f1fd37;hpb=f129784b67308e149e458c9dfbdf245535ab2a8f diff --git a/packages/sdl2.nuget.2.0.22/build/native/include/SDL_bits.h b/packages/sdl2.nuget.2.0.22/build/native/include/SDL_bits.h new file mode 100644 index 00000000..22cb8531 --- /dev/null +++ b/packages/sdl2.nuget.2.0.22/build/native/include/SDL_bits.h @@ -0,0 +1,126 @@ +/* + Simple DirectMedia Layer + Copyright (C) 1997-2022 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. +*/ + +/** + * \file SDL_bits.h + * + * Functions for fiddling with bits and bitmasks. + */ + +#ifndef SDL_bits_h_ +#define SDL_bits_h_ + +#include "SDL_stdinc.h" + +#include "begin_code.h" +/* Set up for C function definitions, even when using C++ */ +#ifdef __cplusplus +extern "C" { +#endif + +/** + * \file SDL_bits.h + */ + +/** + * Get the index of the most significant bit. Result is undefined when called + * with 0. This operation can also be stated as "count leading zeroes" and + * "log base 2". + * + * \return the index of the most significant bit, or -1 if the value is 0. + */ +#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 + +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) + unsigned long index; + if (_BitScanReverse(&index, x)) { + return 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 +} + +SDL_FORCE_INLINE SDL_bool +SDL_HasExactlyOneBitSet32(Uint32 x) +{ + if (x && !(x & (x - 1))) { + return SDL_TRUE; + } + return SDL_FALSE; +} + +/* Ends C function definitions when using C++ */ +#ifdef __cplusplus +} +#endif +#include "close_code.h" + +#endif /* SDL_bits_h_ */ + +/* vi: set ts=4 sw=4 expandtab: */