1/// @ref gtc_color_space 2/// @file glm/gtc/color_space.inl 3 4namespace glm{ 5namespace detail 6{ 7 template<length_t L, typename T, qualifier Q> 8 struct compute_rgbToSrgb 9 { 10 GLM_FUNC_QUALIFIER static vec<L, T, Q> call(vec<L, T, Q> const& ColorRGB, T GammaCorrection) 11 { 12 vec<L, T, Q> const ClampedColor(clamp(ColorRGB, static_cast<T>(0), static_cast<T>(1))); 13 14 return mix( 15 pow(ClampedColor, vec<L, T, Q>(GammaCorrection)) * static_cast<T>(1.055) - static_cast<T>(0.055), 16 ClampedColor * static_cast<T>(12.92), 17 lessThan(ClampedColor, vec<L, T, Q>(static_cast<T>(0.0031308)))); 18 } 19 }; 20 21 template<typename T, qualifier Q> 22 struct compute_rgbToSrgb<4, T, Q> 23 { 24 GLM_FUNC_QUALIFIER static vec<4, T, Q> call(vec<4, T, Q> const& ColorRGB, T GammaCorrection) 25 { 26 return vec<4, T, Q>(compute_rgbToSrgb<3, T, Q>::call(vec<3, T, Q>(ColorRGB), GammaCorrection), ColorRGB.w); 27 } 28 }; 29 30 template<length_t L, typename T, qualifier Q> 31 struct compute_srgbToRgb 32 { 33 GLM_FUNC_QUALIFIER static vec<L, T, Q> call(vec<L, T, Q> const& ColorSRGB, T Gamma) 34 { 35 return mix( 36 pow((ColorSRGB + static_cast<T>(0.055)) * static_cast<T>(0.94786729857819905213270142180095), vec<L, T, Q>(Gamma)), 37 ColorSRGB * static_cast<T>(0.07739938080495356037151702786378), 38 lessThanEqual(ColorSRGB, vec<L, T, Q>(static_cast<T>(0.04045)))); 39 } 40 }; 41 42 template<typename T, qualifier Q> 43 struct compute_srgbToRgb<4, T, Q> 44 { 45 GLM_FUNC_QUALIFIER static vec<4, T, Q> call(vec<4, T, Q> const& ColorSRGB, T Gamma) 46 { 47 return vec<4, T, Q>(compute_srgbToRgb<3, T, Q>::call(vec<3, T, Q>(ColorSRGB), Gamma), ColorSRGB.w); 48 } 49 }; 50}//namespace detail 51 52 template<length_t L, typename T, qualifier Q> 53 GLM_FUNC_QUALIFIER vec<L, T, Q> convertLinearToSRGB(vec<L, T, Q> const& ColorLinear) 54 { 55 return detail::compute_rgbToSrgb<L, T, Q>::call(ColorLinear, static_cast<T>(0.41666)); 56 } 57 58 // Based on Ian Taylor http://chilliant.blogspot.fr/2012/08/srgb-approximations-for-hlsl.html 59 template<> 60 GLM_FUNC_QUALIFIER vec<3, float, lowp> convertLinearToSRGB(vec<3, float, lowp> const& ColorLinear) 61 { 62 vec<3, float, lowp> S1 = sqrt(ColorLinear); 63 vec<3, float, lowp> S2 = sqrt(S1); 64 vec<3, float, lowp> S3 = sqrt(S2); 65 return 0.662002687f * S1 + 0.684122060f * S2 - 0.323583601f * S3 - 0.0225411470f * ColorLinear; 66 } 67 68 template<length_t L, typename T, qualifier Q> 69 GLM_FUNC_QUALIFIER vec<L, T, Q> convertLinearToSRGB(vec<L, T, Q> const& ColorLinear, T Gamma) 70 { 71 return detail::compute_rgbToSrgb<L, T, Q>::call(ColorLinear, static_cast<T>(1) / Gamma); 72 } 73 74 template<length_t L, typename T, qualifier Q> 75 GLM_FUNC_QUALIFIER vec<L, T, Q> convertSRGBToLinear(vec<L, T, Q> const& ColorSRGB) 76 { 77 return detail::compute_srgbToRgb<L, T, Q>::call(ColorSRGB, static_cast<T>(2.4)); 78 } 79 80 template<length_t L, typename T, qualifier Q> 81 GLM_FUNC_QUALIFIER vec<L, T, Q> convertSRGBToLinear(vec<L, T, Q> const& ColorSRGB, T Gamma) 82 { 83 return detail::compute_srgbToRgb<L, T, Q>::call(ColorSRGB, Gamma); 84 } 85}//namespace glm 86