michael@0: //
michael@0: // Copyright (c) 2002-2012 The ANGLE Project Authors. All rights reserved.
michael@0: // Use of this source code is governed by a BSD-style license that can be
michael@0: // found in the LICENSE file.
michael@0: //
michael@0: 
michael@0: // mathutil.h: Math and bit manipulation functions.
michael@0: 
michael@0: #ifndef LIBGLESV2_MATHUTIL_H_
michael@0: #define LIBGLESV2_MATHUTIL_H_
michael@0: 
michael@0: #include <intrin.h>
michael@0: 
michael@0: #include "common/system.h"
michael@0: #include "common/debug.h"
michael@0: 
michael@0: namespace gl
michael@0: {
michael@0: struct Vector4
michael@0: {
michael@0:     Vector4() {}
michael@0:     Vector4(float x, float y, float z, float w) : x(x), y(y), z(z), w(w) {}
michael@0: 
michael@0:     float x;
michael@0:     float y;
michael@0:     float z;
michael@0:     float w;
michael@0: };
michael@0: 
michael@0: inline bool isPow2(int x)
michael@0: {
michael@0:     return (x & (x - 1)) == 0 && (x != 0);
michael@0: }
michael@0: 
michael@0: inline int log2(int x)
michael@0: {
michael@0:     int r = 0;
michael@0:     while ((x >> r) > 1) r++;
michael@0:     return r;
michael@0: }
michael@0: 
michael@0: inline unsigned int ceilPow2(unsigned int x)
michael@0: {
michael@0:     if (x != 0) x--;
michael@0:     x |= x >> 1;
michael@0:     x |= x >> 2;
michael@0:     x |= x >> 4;
michael@0:     x |= x >> 8;
michael@0:     x |= x >> 16;
michael@0:     x++;
michael@0: 
michael@0:     return x;
michael@0: }
michael@0: 
michael@0: template<typename T, typename MIN, typename MAX>
michael@0: inline T clamp(T x, MIN min, MAX max)
michael@0: {
michael@0:     // Since NaNs fail all comparison tests, a NaN value will default to min
michael@0:     return x > min ? (x > max ? max : x) : min;
michael@0: }
michael@0: 
michael@0: inline float clamp01(float x)
michael@0: {
michael@0:     return clamp(x, 0.0f, 1.0f);
michael@0: }
michael@0: 
michael@0: template<const int n>
michael@0: inline unsigned int unorm(float x)
michael@0: {
michael@0:     const unsigned int max = 0xFFFFFFFF >> (32 - n);
michael@0: 
michael@0:     if (x > 1)
michael@0:     {
michael@0:         return max;
michael@0:     }
michael@0:     else if (x < 0)
michael@0:     {
michael@0:         return 0;
michael@0:     }
michael@0:     else
michael@0:     {
michael@0:         return (unsigned int)(max * x + 0.5f);
michael@0:     }
michael@0: }
michael@0: 
michael@0: inline bool supportsSSE2()
michael@0: {
michael@0:     static bool checked = false;
michael@0:     static bool supports = false;
michael@0: 
michael@0:     if (checked)
michael@0:     {
michael@0:         return supports;
michael@0:     }
michael@0: 
michael@0:     int info[4];
michael@0:     __cpuid(info, 0);
michael@0:     
michael@0:     if (info[0] >= 1)
michael@0:     {
michael@0:         __cpuid(info, 1);
michael@0: 
michael@0:         supports = (info[3] >> 26) & 1;
michael@0:     }
michael@0: 
michael@0:     checked = true;
michael@0: 
michael@0:     return supports;
michael@0: }
michael@0: 
michael@0: inline unsigned short float32ToFloat16(float fp32)
michael@0: {
michael@0:     unsigned int fp32i = (unsigned int&)fp32;
michael@0:     unsigned int sign = (fp32i & 0x80000000) >> 16;
michael@0:     unsigned int abs = fp32i & 0x7FFFFFFF;
michael@0: 
michael@0:     if(abs > 0x47FFEFFF)   // Infinity
michael@0:     {
michael@0:         return sign | 0x7FFF;
michael@0:     }
michael@0:     else if(abs < 0x38800000)   // Denormal
michael@0:     {
michael@0:         unsigned int mantissa = (abs & 0x007FFFFF) | 0x00800000;   
michael@0:         int e = 113 - (abs >> 23);
michael@0: 
michael@0:         if(e < 24)
michael@0:         {
michael@0:             abs = mantissa >> e;
michael@0:         }
michael@0:         else
michael@0:         {
michael@0:             abs = 0;
michael@0:         }
michael@0: 
michael@0:         return sign | (abs + 0x00000FFF + ((abs >> 13) & 1)) >> 13;
michael@0:     }
michael@0:     else
michael@0:     {
michael@0:         return sign | (abs + 0xC8000000 + 0x00000FFF + ((abs >> 13) & 1)) >> 13;
michael@0:     }
michael@0: }
michael@0: 
michael@0: float float16ToFloat32(unsigned short h);
michael@0: 
michael@0: }
michael@0: 
michael@0: namespace rx
michael@0: {
michael@0: 
michael@0: struct Range
michael@0: {
michael@0:     Range() {}
michael@0:     Range(int lo, int hi) : start(lo), end(hi) { ASSERT(lo <= hi); }
michael@0: 
michael@0:     int start;
michael@0:     int end;
michael@0: };
michael@0: 
michael@0: }
michael@0: 
michael@0: #endif   // LIBGLESV2_MATHUTIL_H_