0.9.9/api/a00491_source.html

 #pragma once

 // Dependency:
 #include "../gtc/constants.hpp"

 #ifndef GLM_ENABLE_EXPERIMENTAL
 #   error "GLM: GLM_GTX_fast_trigonometry is an experimental extension and may change in the future. Use #define GLM_ENABLE_EXPERIMENTAL before including it, if you really want to use it."
 #endif

 #if GLM_MESSAGES == GLM_ENABLE && !defined(GLM_EXT_INCLUDED)
 #   pragma message("GLM: GLM_GTX_fast_trigonometry extension included")
 #endif

 namespace glm
 {

     template<typename T>
     GLM_FUNC_DECL T wrapAngle(T angle);

     template<typename T>
     GLM_FUNC_DECL T fastSin(T angle);

     template<typename T>
     GLM_FUNC_DECL T fastCos(T angle);

     template<typename T>
     GLM_FUNC_DECL T fastTan(T angle);

     template<typename T>
     GLM_FUNC_DECL T fastAsin(T angle);

     template<typename T>
     GLM_FUNC_DECL T fastAcos(T angle);

     template<typename T>
     GLM_FUNC_DECL T fastAtan(T y, T x);

     template<typename T>
     GLM_FUNC_DECL T fastAtan(T angle);

 }//namespace glm

 #include "fast_trigonometry.inl"
glm::fastAsin
GLM_FUNC_DECL T fastAsin(T angle)
Faster than the common asin function but less accurate.

glm::fastAtan
GLM_FUNC_DECL T fastAtan(T angle)
Faster than the common atan function but less accurate.

glm::fastTan
GLM_FUNC_DECL T fastTan(T angle)
Faster than the common tan function but less accurate.

glm::fastCos
GLM_FUNC_DECL T fastCos(T angle)
Faster than the common cos function but less accurate.

glm::wrapAngle
GLM_FUNC_DECL T wrapAngle(T angle)
Wrap an angle to [0 2pi[ From GLM_GTX_fast_trigonometry extension.

glm::fastAcos
GLM_FUNC_DECL T fastAcos(T angle)
Faster than the common acos function but less accurate.

glm::fastSin
GLM_FUNC_DECL T fastSin(T angle)
Faster than the common sin function but less accurate.

glm
Definition: common.hpp:20

glm::angle
GLM_FUNC_DECL T angle(qua< T, Q > const &x)
Returns the quaternion rotation angle.