1 /////////////////////////////////////////////////////////////////////////////////////////////////// 2 // OpenGL Mathematics Copyright (c) 2005 - 2014 G-Truc Creation (www.g-truc.net) 3 /////////////////////////////////////////////////////////////////////////////////////////////////// 4 // Created : 2009-03-06 5 // Updated : 2013-04-09 6 // Licence : This source is under MIT License 7 // File : glm/gtx/gradient_paint.inl 8 /////////////////////////////////////////////////////////////////////////////////////////////////// 9 10 namespace glm 11 { 12 template <typename T, precision P> 13 GLM_FUNC_QUALIFIER T radialGradient 14 ( 15 detail::tvec2<T, P> const & Center, 16 T const & Radius, 17 detail::tvec2<T, P> const & Focal, 18 detail::tvec2<T, P> const & Position 19 ) 20 { 21 detail::tvec2<T, P> F = Focal - Center; 22 detail::tvec2<T, P> D = Position - Focal; 23 T Radius2 = pow2(Radius); 24 T Fx2 = pow2(F.x); 25 T Fy2 = pow2(F.y); 26 27 T Numerator = (D.x * F.x + D.y * F.y) + sqrt(Radius2 * (pow2(D.x) + pow2(D.y)) - pow2(D.x * F.y - D.y * F.x)); 28 T Denominator = Radius2 - (Fx2 + Fy2); 29 return Numerator / Denominator; 30 } 31 32 template <typename T, precision P> 33 GLM_FUNC_QUALIFIER T linearGradient 34 ( 35 detail::tvec2<T, P> const & Point0, 36 detail::tvec2<T, P> const & Point1, 37 detail::tvec2<T, P> const & Position 38 ) 39 { 40 detail::tvec2<T, P> Dist = Point1 - Point0; 41 return (Dist.x * (Position.x - Point0.x) + Dist.y * (Position.y - Point0.y)) / glm::dot(Dist, Dist); 42 } 43 }//namespace glm 44
