1 // 2 // Copyright (c) 2002-2010 The ANGLE Project Authors. All rights reserved. 3 // Use of this source code is governed by a BSD-style license that can be 4 // found in the LICENSE file. 5 // 6 7 // mathutil.h: Math and bit manipulation functions. 8 9 #ifndef LIBGLESV2_MATHUTIL_H_ 10 #define LIBGLESV2_MATHUTIL_H_ 11 12 #include <math.h> 13 14 namespace gl 15 { isPow2(int x)16inline bool isPow2(int x) 17 { 18 return (x & (x - 1)) == 0 && (x != 0); 19 } 20 log2(int x)21inline int log2(int x) 22 { 23 int r = 0; 24 while ((x >> r) > 1) r++; 25 return r; 26 } 27 ceilPow2(unsigned int x)28inline unsigned int ceilPow2(unsigned int x) 29 { 30 if (x != 0) x--; 31 x |= x >> 1; 32 x |= x >> 2; 33 x |= x >> 4; 34 x |= x >> 8; 35 x |= x >> 16; 36 x++; 37 38 return x; 39 } 40 clamp01(float x)41inline float clamp01(float x) 42 { 43 return x < 0 ? 0 : (x > 1 ? 1 : x); 44 } 45 46 template<const int n> unorm(float x)47inline unsigned int unorm(float x) 48 { 49 const unsigned int max = 0xFFFFFFFF >> (32 - n); 50 51 if (x > 1) 52 { 53 return max; 54 } 55 else if (x < 0) 56 { 57 return 0; 58 } 59 else 60 { 61 return (unsigned int)(max * x + 0.5f); 62 } 63 } 64 } 65 66 #endif // LIBGLESV2_MATHUTIL_H_ 67