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/* 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"
#ifndef M_SQRT1_2
#define M_SQRT1_2 0.70710678118654752440 /* 1/sqrt(2) */
#endif
#ifndef M_PI
#define M_PI 3.14159265358979323846
#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 defined(__GNUC__) && (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 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);
}
#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
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