color_space.inl

 
 
namespace glm
{
    template<typename T, qualifier Q>
    GLM_FUNC_QUALIFIER vec<3, T, Q> rgbColor(const vec<3, T, Q>& hsvColor)
    {
        vec<3, T, Q> hsv = hsvColor;
        vec<3, T, Q> rgbColor;
 
        if(hsv.y == static_cast<T>(0))
            // achromatic (grey)
            rgbColor = vec<3, T, Q>(hsv.z);
        else
        {
            T sector = floor(hsv.x * (T(1) / T(60)));
            T frac = (hsv.x * (T(1) / T(60))) - sector;
            // factorial part of h
            T o = hsv.z * (T(1) - hsv.y);
            T p = hsv.z * (T(1) - hsv.y * frac);
            T q = hsv.z * (T(1) - hsv.y * (T(1) - frac));
 
            switch(int(sector))
            {
            default:
            case 0:
                rgbColor.r = hsv.z;
                rgbColor.g = q;
                rgbColor.b = o;
                break;
            case 1:
                rgbColor.r = p;
                rgbColor.g = hsv.z;
                rgbColor.b = o;
                break;
            case 2:
                rgbColor.r = o;
                rgbColor.g = hsv.z;
                rgbColor.b = q;
                break;
            case 3:
                rgbColor.r = o;
                rgbColor.g = p;
                rgbColor.b = hsv.z;
                break;
            case 4:
                rgbColor.r = q;
                rgbColor.g = o;
                rgbColor.b = hsv.z;
                break;
            case 5:
                rgbColor.r = hsv.z;
                rgbColor.g = o;
                rgbColor.b = p;
                break;
            }
        }
 
        return rgbColor;
    }
 
    template<typename T, qualifier Q>
    GLM_FUNC_QUALIFIER vec<3, T, Q> hsvColor(const vec<3, T, Q>& rgbColor)
    {
        vec<3, T, Q> hsv = rgbColor;
        float Min   = min(min(rgbColor.r, rgbColor.g), rgbColor.b);
        float Max   = max(max(rgbColor.r, rgbColor.g), rgbColor.b);
        float Delta = Max - Min;
 
        hsv.z = Max;
 
        if(Max != static_cast<T>(0))
        {
            hsv.y = Delta / hsv.z;
            T h = static_cast<T>(0);
 
            if(rgbColor.r == Max)
                // between yellow & magenta
                h = static_cast<T>(0) + T(60) * (rgbColor.g - rgbColor.b) / Delta;
            else if(rgbColor.g == Max)
                // between cyan & yellow
                h = static_cast<T>(120) + T(60) * (rgbColor.b - rgbColor.r) / Delta;
            else
                // between magenta & cyan
                h = static_cast<T>(240) + T(60) * (rgbColor.r - rgbColor.g) / Delta;
 
            if(h < T(0))
                hsv.x = h + T(360);
            else
                hsv.x = h;
        }
        else
        {
            // If r = g = b = 0 then s = 0, h is undefined
            hsv.y = static_cast<T>(0);
            hsv.x = static_cast<T>(0);
        }
 
        return hsv;
    }
 
    template<typename T>
    GLM_FUNC_QUALIFIER mat<4, 4, T, defaultp> saturation(T const s)
    {
        vec<3, T, defaultp> rgbw = vec<3, T, defaultp>(T(0.2126), T(0.7152), T(0.0722));
 
        vec<3, T, defaultp> const col((T(1) - s) * rgbw);
 
        mat<4, 4, T, defaultp> result(T(1));
        result[0][0] = col.x + s;
        result[0][1] = col.x;
        result[0][2] = col.x;
        result[1][0] = col.y;
        result[1][1] = col.y + s;
        result[1][2] = col.y;
        result[2][0] = col.z;
        result[2][1] = col.z;
        result[2][2] = col.z + s;
 
        return result;
    }
 
    template<typename T, qualifier Q>
    GLM_FUNC_QUALIFIER vec<3, T, Q> saturation(const T s, const vec<3, T, Q>& color)
    {
        return vec<3, T, Q>(saturation(s) * vec<4, T, Q>(color, T(0)));
    }
 
    template<typename T, qualifier Q>
    GLM_FUNC_QUALIFIER vec<4, T, Q> saturation(const T s, const vec<4, T, Q>& color)
    {
        return saturation(s) * color;
    }
 
    template<typename T, qualifier Q>
    GLM_FUNC_QUALIFIER T luminosity(const vec<3, T, Q>& color)
    {
        const vec<3, T, Q> tmp = vec<3, T, Q>(0.33, 0.59, 0.11);
        return dot(color, tmp);
    }
}//namespace glm