AOO410/main/slideshow/source/inc/hslcolor.hxx

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#ifndef INCLUDED_SLIDESHOW_HSLCOLOR_HXX
#define INCLUDED_SLIDESHOW_HSLCOLOR_HXX

#include <cppcanvas/color.hxx>


/* Definition of HSLColor class */

namespace slideshow
{
    namespace internal
    {
        class RGBColor;

        /** HSL color space class.        
         */
        class HSLColor
        {
        public:
            HSLColor();
            explicit HSLColor( ::cppcanvas::Color::IntSRGBA nRGBColor );
            HSLColor( double nHue, double nSaturation, double nLuminance );
            explicit HSLColor( const RGBColor& rColor );

            /** Hue of the color.
                
            	@return hue, is in the range [0,360]
             */
            double getHue() const;

            /** Saturation of the color.
                
            	@return saturation, is in the range [0,1]
             */
            double getSaturation() const;

            /** Luminance of the color.
                
            	@return luminance, is in the range [0,1]
             */
            double getLuminance() const;

            /** Get the RGB red value.
             */
            double getRed() const;

            /** Get the RGB green value.
             */
            double getGreen() const;

            /** Get the RGB blue value.
             */
            double getBlue() const;

            /** Create an RGB color object.
             */
            RGBColor getRGBColor() const;

            struct HSLTriple
            {
                HSLTriple();
                HSLTriple( double nHue, double nSaturation, double nLuminance );

                double mnHue;
                double mnSaturation;
                double mnLuminance;
            };

        private:
            // default copy/assignment are okay
            // HSLColor(const HSLColor&);            
            // HSLColor& operator=( const HSLColor& );

            HSLTriple	maHSLTriple;

            /// Pre-calculated value, needed for conversion back to RGB
            double 		mnMagicValue;
        };        

        HSLColor operator+( const HSLColor& rLHS, const HSLColor& rRHS );
        HSLColor operator*( const HSLColor& rLHS, const HSLColor& rRHS );
        HSLColor operator*( double nFactor, const HSLColor& rRHS );

        /** HSL color linear interpolator.
            
            @param t
            As usual, t must be in the [0,1] range

            @param bCCW
            When true, hue interpolation happens counter-clockwise
        */
        HSLColor interpolate( const HSLColor& rFrom, const HSLColor& rTo, double t, bool bCCW=true );
    }
}

#endif /* INCLUDED_SLIDESHOW_HSLCOLOR_HXX */