mirror of
https://github.com/libretro/scummvm.git
synced 2024-12-24 18:56:33 +00:00
26a9b528da
This should have no effect on common/math.h as scummsys is included at the top anyway, but this will fix compilation on some toolchains when strict ANSI language compliance is enabled i.e. -std=c++11, rather than -std=gnu11. This causes an issue as a side effect is to set a guard which disables various non-standard defines in the system headers i.e. the M_PI and M_SQRT1_2 constant definitions in the MinGW x86_64 toolchain on buildbot. By moving this into scummsys.h after the point of system math.h inclusion, we can ensure that M_PI etc. are always present.
121 lines
3.6 KiB
C++
121 lines
3.6 KiB
C++
/* ScummVM - Graphic Adventure Engine
|
|
*
|
|
* ScummVM is the legal property of its developers, whose names
|
|
* are too numerous to list here. Please refer to the COPYRIGHT
|
|
* file distributed with this source distribution.
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version 2
|
|
* of the License, or (at your option) any later version.
|
|
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
|
|
*
|
|
*/
|
|
|
|
// Based on eos' math code
|
|
|
|
#ifndef COMMON_MATH_H
|
|
#define COMMON_MATH_H
|
|
|
|
#include "common/scummsys.h"
|
|
#ifdef _MSC_VER
|
|
// HACK:
|
|
// intrin.h on MSVC includes setjmp.h, which will fail compiling due to our
|
|
// forbidden symbol colde. Since we also can not assure that defining
|
|
// FORBIDDEN_SYMBOL_EXCEPTION_setjmp and FORBIDDEN_SYMBOL_EXCEPTION_longjmp
|
|
// will actually allow the symbols, since forbidden.h might be included
|
|
// earlier already we need to undefine them here...
|
|
#undef setjmp
|
|
#undef longjmp
|
|
#include <intrin.h>
|
|
// ...and redefine them here so no code can actually use it.
|
|
// This could be resolved by including intrin.h on MSVC in scummsys.h before
|
|
// the forbidden.h include. This might make sense, in case we use MSVC
|
|
// extensions like _BitScanReverse in more places. But for now this hack should
|
|
// be ok...
|
|
#ifndef FORBIDDEN_SYMBOL_EXCEPTION_setjmp
|
|
#undef setjmp
|
|
#define setjmp(a) FORBIDDEN_SYMBOL_REPLACEMENT
|
|
#endif
|
|
|
|
#ifndef FORBIDDEN_SYMBOL_EXCEPTION_longjmp
|
|
#undef longjmp
|
|
#define longjmp(a,b) FORBIDDEN_SYMBOL_REPLACEMENT
|
|
#endif
|
|
#endif
|
|
|
|
#ifndef FLT_MIN
|
|
#define FLT_MIN 1E-37
|
|
#endif
|
|
|
|
#ifndef FLT_MAX
|
|
#define FLT_MAX 1E+37
|
|
#endif
|
|
|
|
namespace Common {
|
|
|
|
/** A complex number. */
|
|
struct Complex {
|
|
float re, im;
|
|
};
|
|
|
|
#if GCC_ATLEAST(3, 4)
|
|
inline int intLog2(uint32 v) {
|
|
// This is a slightly optimized implementation of log2 for natural numbers
|
|
// targeting gcc. It also saves some binary size over our fallback
|
|
// implementation, since it does not need any table.
|
|
if (v == 0)
|
|
return -1;
|
|
else
|
|
// This is really "sizeof(unsigned int) * CHAR_BIT - 1" but using 8
|
|
// instead of CHAR_BIT is sane enough and it saves us from including
|
|
// limits.h
|
|
return (sizeof(unsigned int) * 8 - 1) - __builtin_clz(v);
|
|
}
|
|
#elif defined(_MSC_VER)
|
|
inline int intLog2(uint32 v) {
|
|
unsigned long result = 0;
|
|
unsigned char nonZero = _BitScanReverse(&result, v);
|
|
// _BitScanReverse stores the position of the MSB set in case its result
|
|
// is non zero, thus we can just return it as is.
|
|
return nonZero ? result : -1;
|
|
}
|
|
#else
|
|
// See http://graphics.stanford.edu/~seander/bithacks.html#IntegerLogLookup
|
|
static const char LogTable256[256] = {
|
|
#define LT(n) n, n, n, n, n, n, n, n, n, n, n, n, n, n, n, n
|
|
-1, 0, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3,
|
|
LT(4), LT(5), LT(5), LT(6), LT(6), LT(6), LT(6),
|
|
LT(7), LT(7), LT(7), LT(7), LT(7), LT(7), LT(7), LT(7)
|
|
};
|
|
|
|
inline int intLog2(uint32 v) {
|
|
register uint32 t, tt;
|
|
|
|
if ((tt = v >> 16))
|
|
return (t = tt >> 8) ? 24 + LogTable256[t] : 16 + LogTable256[tt];
|
|
else
|
|
return (t = v >> 8) ? 8 + LogTable256[t] : LogTable256[v];
|
|
}
|
|
#endif
|
|
|
|
inline float rad2deg(float rad) {
|
|
return rad * 180.0 / M_PI;
|
|
}
|
|
|
|
inline float deg2rad(float deg) {
|
|
return deg * M_PI / 180.0;
|
|
}
|
|
|
|
} // End of namespace Common
|
|
|
|
#endif // COMMON_MATH_H
|