# JustRenderIt / Dependencies / Include / glm / gtx / integer.inl

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204``` ```/////////////////////////////////////////////////////////////////////////////////////////////////// // OpenGL Mathematics Copyright (c) 2005 - 2012 G-Truc Creation (www.g-truc.net) /////////////////////////////////////////////////////////////////////////////////////////////////// // Created : 2005-12-24 // Updated : 2011-10-13 // Licence : This source is under MIT License // File : glm/gtx/integer.inl /////////////////////////////////////////////////////////////////////////////////////////////////// namespace glm { // pow GLM_FUNC_QUALIFIER int pow(int x, int y) { if(y == 0) return 1; int result = x; for(int i = 1; i < y; ++i) result *= x; return result; } // sqrt: From Christopher J. Musial, An integer square root, Graphics Gems, 1990, page 387 GLM_FUNC_QUALIFIER int sqrt(int x) { if(x <= 1) return x; int NextTrial = x >> 1; int CurrentAnswer; do { CurrentAnswer = NextTrial; NextTrial = (NextTrial + x / NextTrial) >> 1; } while(NextTrial < CurrentAnswer); return CurrentAnswer; } // Henry Gordon Dietz: http://aggregate.org/MAGIC/ namespace _detail { GLM_FUNC_QUALIFIER unsigned int ones32(unsigned int x) { /* 32-bit recursive reduction using SWAR... but first step is mapping 2-bit values into sum of 2 1-bit values in sneaky way */ x -= ((x >> 1) & 0x55555555); x = (((x >> 2) & 0x33333333) + (x & 0x33333333)); x = (((x >> 4) + x) & 0x0f0f0f0f); x += (x >> 8); x += (x >> 16); return(x & 0x0000003f); } template <> struct _compute_log2 { template GLM_FUNC_QUALIFIER T operator() (T const & Value) const { #if(GLM_COMPILER & GLM_COMPILER_VC) return Value <= T(1) ? T(0) : T(32) - nlz(Value - T(1)); #elif(GLM_COMPILER & GLM_COMPILER_GCC) return Value <= T(1) ? T(0) : nlz(Value - T(1)) + 1; #else return T(32) - nlz(Value - T(1)); #endif } }; }//namespace _detail // Henry Gordon Dietz: http://aggregate.org/MAGIC/ GLM_FUNC_QUALIFIER unsigned int floor_log2(unsigned int x) { x |= (x >> 1); x |= (x >> 2); x |= (x >> 4); x |= (x >> 8); x |= (x >> 16); return(_detail::ones32(x) - 1); } // mod GLM_FUNC_QUALIFIER int mod(int x, int y) { return x - y * (x / y); } // factorial (!12 max, integer only) template GLM_FUNC_QUALIFIER genType factorial(genType const & x) { genType Temp = x; genType Result; for(Result = 1; Temp > 1; --Temp) Result *= Temp; return Result; } template GLM_FUNC_QUALIFIER detail::tvec2 factorial( detail::tvec2 const & x) { return detail::tvec2( factorial(x.x), factorial(x.y)); } template GLM_FUNC_QUALIFIER detail::tvec3 factorial( detail::tvec3 const & x) { return detail::tvec3( factorial(x.x), factorial(x.y), factorial(x.z)); } template GLM_FUNC_QUALIFIER detail::tvec4 factorial( detail::tvec4 const & x) { return detail::tvec4( factorial(x.x), factorial(x.y), factorial(x.z), factorial(x.w)); } GLM_FUNC_QUALIFIER uint pow(uint x, uint y) { uint result = x; for(uint i = 1; i < y; ++i) result *= x; return result; } GLM_FUNC_QUALIFIER uint sqrt(uint x) { if(x <= 1) return x; uint NextTrial = x >> 1; uint CurrentAnswer; do { CurrentAnswer = NextTrial; NextTrial = (NextTrial + x / NextTrial) >> 1; } while(NextTrial < CurrentAnswer); return CurrentAnswer; } GLM_FUNC_QUALIFIER uint mod(uint x, uint y) { return x - y * (x / y); } #if(GLM_COMPILER & (GLM_COMPILER_VC | GLM_COMPILER_GCC)) GLM_FUNC_QUALIFIER unsigned int nlz(unsigned int x) { return 31u - findMSB(x); } #else // Hackers Delight: http://www.hackersdelight.org/HDcode/nlz.c.txt GLM_FUNC_QUALIFIER unsigned int nlz(unsigned int x) { int y, m, n; y = -int(x >> 16); // If left half of x is 0, m = (y >> 16) & 16; // set n = 16. If left half n = 16 - m; // is nonzero, set n = 0 and x = x >> m; // shift x right 16. // Now x is of the form 0000xxxx. y = x - 0x100; // If positions 8-15 are 0, m = (y >> 16) & 8; // add 8 to n and shift x left 8. n = n + m; x = x << m; y = x - 0x1000; // If positions 12-15 are 0, m = (y >> 16) & 4; // add 4 to n and shift x left 4. n = n + m; x = x << m; y = x - 0x4000; // If positions 14-15 are 0, m = (y >> 16) & 2; // add 2 to n and shift x left 2. n = n + m; x = x << m; y = x >> 14; // Set y = 0, 1, 2, or 3. m = y & ~(y >> 1); // Set m = 0, 1, 2, or 2 resp. return unsigned(n + 2 - m); } #endif//(GLM_COMPILER) }//namespace glm ```