VGColor.h

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#ifndef VGColor_H
#define VGColor_H

/*
  GUIDO Library
  Copyright (C) 2006    Grame

  This Source Code Form is subject to the terms of the Mozilla Public
  License, v. 2.0. If a copy of the MPL was not distributed with this
  file, You can obtain one at http://mozilla.org/MPL/2.0/.

  Grame Research Laboratory, 11, cours de Verdun Gensoul 69002 Lyon - France
  research@grame.fr

*/

#include <iostream>

// define int constants to bound alpha values
#define ALPHA_TRANSPARENT   0
#define ALPHA_OPAQUE        255


// --------------------------------------------------------------
//      VGColor class
// --------------------------------------------------------------
class VGColor
{
    public:     
                    VGColor( unsigned char gray  = 0 ) 
                        : mRed( gray ), mGreen( gray ), mBlue( gray ), mAlpha( ALPHA_OPAQUE ) { }
                    VGColor( const VGColor & in ) 
                        { Set( in ); }
                    VGColor( unsigned char r, unsigned char g, 
                             unsigned char b, unsigned char a = ALPHA_OPAQUE ) 
                        : mRed( r ), mGreen( g ), mBlue ( b ), mAlpha( a ) { }

        explicit    VGColor( const unsigned char col [4] ) 
                        { if( col ) Set( col[0], col[1], col[2], col[3] ); else Set( 0 ); }

        void        Set( unsigned char r, unsigned char g, 
                         unsigned char b, unsigned char a = ALPHA_OPAQUE )
                        { mRed = r; mGreen = g; mBlue = b, mAlpha = a; }
        void        Set( const VGColor & in )
                        { mRed = in.mRed; mGreen = in.mGreen; mBlue = in.mBlue, mAlpha = in.mAlpha; }

                
        bool        operator == ( const VGColor & col ) const
                        { return (( col.mRed == mRed ) && ( col.mGreen == mGreen ) 
                          && ( col.mBlue == mBlue ) && ( col.mAlpha == mAlpha )); }
        
        bool        operator != ( const VGColor & col ) const
                        { return (( col.mRed != mRed ) || ( col.mGreen != mGreen ) 
                          || ( col.mBlue != mBlue ) || ( col.mAlpha != mAlpha )); }
                
        VGColor &   operator += ( short v );

        //modifications of this method must be applied also in the action parser.
        //This fonction displays color as html does.  ex : #45fc0a[ff]
        std::ostream& print(std::ostream& out) const
        {
            out << "#";
            char prev = out.fill ('0');
            out.width(2);out << std::hex << int(mRed);
            out.width(2);out << std::hex << int(mGreen);
            out.width(2);out << std::hex << int(mBlue);
            out.width(1);out << "[";
            out.width(2);out << std::hex << int(mAlpha) << std::dec;
            out.width(1);out << "]";
            out.fill(prev);

            return out;
        }
            
        unsigned char mRed;
        unsigned char mGreen;
        unsigned char mBlue;
        unsigned char mAlpha; // 0 = invisible, 255 = opaque. 
};

                
inline VGColor & VGColor::operator += ( short v ) 
{ 
    int sred = mRed + v; 
    mRed   = (unsigned char)((sred > 255) ? 255 : sred);
    int sgreen = mGreen + v;
    mGreen = (unsigned char)((sgreen > 255) ? 255 : sgreen);
    int sblue = mBlue + v;
    mBlue  = (unsigned char)((sblue > 255) ? 255 : sblue);
    return *this;
}

inline std::ostream& operator << (std::ostream& out, const VGColor& c)
{
    return (&c)->print(out);
}


#endif /* VGColor */