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+/// @ref gtx_integer
+/// @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);
+ }
+}//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 <typename genType>
+ GLM_FUNC_QUALIFIER genType factorial(genType const & x)
+ {
+ genType Temp = x;
+ genType Result;
+ for(Result = 1; Temp > 1; --Temp)
+ Result *= Temp;
+ return Result;
+ }
+
+ template <typename T, precision P>
+ GLM_FUNC_QUALIFIER tvec2<T, P> factorial(
+ tvec2<T, P> const & x)
+ {
+ return tvec2<T, P>(
+ factorial(x.x),
+ factorial(x.y));
+ }
+
+ template <typename T, precision P>
+ GLM_FUNC_QUALIFIER tvec3<T, P> factorial(
+ tvec3<T, P> const & x)
+ {
+ return tvec3<T, P>(
+ factorial(x.x),
+ factorial(x.y),
+ factorial(x.z));
+ }
+
+ template <typename T, precision P>
+ GLM_FUNC_QUALIFIER tvec4<T, P> factorial(
+ tvec4<T, P> const & x)
+ {
+ return tvec4<T, P>(
+ 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