diff options
Diffstat (limited to 'src/glm/gtx/fast_square_root.inl')
| -rw-r--r-- | src/glm/gtx/fast_square_root.inl | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/src/glm/gtx/fast_square_root.inl b/src/glm/gtx/fast_square_root.inl new file mode 100644 index 0000000..76d0e15 --- /dev/null +++ b/src/glm/gtx/fast_square_root.inl @@ -0,0 +1,237 @@ +///////////////////////////////////////////////////////////////////////////////////////////////////
+// OpenGL Mathematics Copyright (c) 2005 - 2011 G-Truc Creation (www.g-truc.net)
+///////////////////////////////////////////////////////////////////////////////////////////////////
+// Created : 2006-01-04
+// Updated : 2008-10-07
+// Licence : This source is under MIT License
+// File : glm/gtx/fast_square_root.inl
+///////////////////////////////////////////////////////////////////////////////////////////////////
+
+namespace glm{
+namespace gtx{
+namespace fast_square_root{
+
+// fastSqrt
+template <typename genType>
+GLM_FUNC_QUALIFIER genType fastSqrt
+(
+ genType const & x
+)
+{
+ return genType(1) / fastInverseSqrt(x);
+}
+
+template <typename valType>
+GLM_FUNC_QUALIFIER detail::tvec2<valType> fastSqrt
+(
+ detail::tvec2<valType> const & x
+)
+{
+ return detail::tvec2<valType>(
+ fastSqrt(x.x),
+ fastSqrt(x.y));
+}
+
+template <typename valType>
+GLM_FUNC_QUALIFIER detail::tvec3<valType> fastSqrt
+(
+ detail::tvec3<valType> const & x
+)
+{
+ return detail::tvec3<valType>(
+ fastSqrt(x.x),
+ fastSqrt(x.y),
+ fastSqrt(x.z));
+}
+
+template <typename valType>
+GLM_FUNC_QUALIFIER detail::tvec4<valType> fastSqrt
+(
+ detail::tvec4<valType> const & x
+)
+{
+ return detail::tvec4<valType>(
+ fastSqrt(x.x),
+ fastSqrt(x.y),
+ fastSqrt(x.z),
+ fastSqrt(x.w));
+}
+
+// fastInversesqrt
+template <typename genType>
+GLM_FUNC_QUALIFIER genType fastInverseSqrt
+(
+ genType const & x
+)
+{
+ genType tmp = x;
+ float xhalf = 0.5f * float(tmp);
+ uint i = *(uint*)&x;
+ i = 0x5f375a86 - (i >> 1);
+ //x = *(float*)&i;
+ //x = *((float*)(char*)&i);
+ tmp = detail::uif(i).f;
+ tmp = tmp * (1.5f - xhalf * tmp * tmp);
+ return genType(tmp);
+}
+
+template <typename valType>
+GLM_FUNC_QUALIFIER detail::tvec2<valType> fastInverseSqrt
+(
+ detail::tvec2<valType> const & x
+)
+{
+ return detail::tvec2<valType>(
+ fastInverseSqrt(x.x),
+ fastInverseSqrt(x.y));
+}
+
+template <typename valType>
+GLM_FUNC_QUALIFIER detail::tvec3<valType> fastInverseSqrt
+(
+ detail::tvec3<valType> const & x
+)
+{
+ return detail::tvec3<valType>(
+ fastInverseSqrt(x.x),
+ fastInverseSqrt(x.y),
+ fastInverseSqrt(x.z));
+}
+
+template <typename valType>
+GLM_FUNC_QUALIFIER detail::tvec4<valType> fastInverseSqrt
+(
+ detail::tvec4<valType> const & x
+)
+{
+ return detail::tvec4<valType>(
+ fastInverseSqrt(x.x),
+ fastInverseSqrt(x.y),
+ fastInverseSqrt(x.z),
+ fastInverseSqrt(x.w));
+}
+
+// fastLength
+template <typename genType>
+GLM_FUNC_QUALIFIER genType fastLength
+(
+ genType const & x
+)
+{
+ return abs(x);
+}
+
+template <typename valType>
+GLM_FUNC_QUALIFIER valType fastLength
+(
+ detail::tvec2<valType> const & x
+)
+{
+ valType sqr = x.x * x.x + x.y * x.y;
+ return fastSqrt(sqr);
+}
+
+template <typename valType>
+GLM_FUNC_QUALIFIER valType fastLength
+(
+ detail::tvec3<valType> const & x
+)
+{
+ valType sqr = x.x * x.x + x.y * x.y + x.z * x.z;
+ return fastSqrt(sqr);
+}
+
+template <typename valType>
+GLM_FUNC_QUALIFIER valType fastLength
+(
+ detail::tvec4<valType> const & x
+)
+{
+ valType sqr = x.x * x.x + x.y * x.y + x.z * x.z + x.w * x.w;
+ return fastSqrt(sqr);
+}
+
+// fastDistance
+template <typename genType>
+GLM_FUNC_QUALIFIER genType fastDistance
+(
+ genType const & x,
+ genType const & y
+)
+{
+ return fastLength(y - x);
+}
+
+template <typename valType>
+GLM_FUNC_QUALIFIER valType fastDistance
+(
+ detail::tvec2<valType> const & x,
+ detail::tvec2<valType> const & y
+)
+{
+ return fastLength(y - x);
+}
+
+template <typename valType>
+GLM_FUNC_QUALIFIER valType fastDistance
+(
+ detail::tvec3<valType> const & x,
+ detail::tvec3<valType> const & y
+)
+{
+ return fastLength(y - x);
+}
+
+template <typename valType>
+GLM_FUNC_QUALIFIER valType fastDistance
+(
+ detail::tvec4<valType> const & x,
+ detail::tvec4<valType> const & y
+)
+{
+ return fastLength(y - x);
+}
+
+// fastNormalize
+template <typename genType>
+GLM_FUNC_QUALIFIER genType fastNormalize
+(
+ genType const & x
+)
+{
+ return x > genType(0) ? genType(1) : -genType(1);
+}
+
+template <typename valType>
+GLM_FUNC_QUALIFIER detail::tvec2<valType> fastNormalize
+(
+ detail::tvec2<valType> const & x
+)
+{
+ valType sqr = x.x * x.x + x.y * x.y;
+ return x * fastInverseSqrt(sqr);
+}
+
+template <typename valType>
+GLM_FUNC_QUALIFIER detail::tvec3<valType> fastNormalize
+(
+ detail::tvec3<valType> const & x
+)
+{
+ valType sqr = x.x * x.x + x.y * x.y + x.z * x.z;
+ return x * fastInverseSqrt(sqr);
+}
+
+template <typename valType>
+GLM_FUNC_QUALIFIER detail::tvec4<valType> fastNormalize
+(
+ detail::tvec4<valType> const & x
+)
+{
+ valType sqr = x.x * x.x + x.y * x.y + x.z * x.z + x.w * x.w;
+ return x * fastInverseSqrt(sqr);
+}
+
+}//namespace fast_square_root
+}//namespace gtx
+}//namespace glm
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