mapnik/include/graphics.hpp

/*****************************************************************************
 * 
 * This file is part of Mapnik (c++ mapping toolkit)
 *
 * Copyright (C) 2006 Artem Pavlenko
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 *****************************************************************************/

//$Id: graphics.hpp 39 2005-04-10 20:39:53Z pavlenko $

#ifndef GRAPHICS_HPP
#define GRAPHICS_HPP

#include <cmath>
#include <string>
#include <cassert>
#include "color.hpp"
#include "gamma.hpp"
#include "image_data.hpp"
#include "envelope.hpp"

namespace mapnik
{
    class MAPNIK_DECL Image32
    {
    private:
        unsigned width_;
        unsigned height_;
        Color background_;
        ImageData32 data_;
    public:
        Image32(int width,int height);
        Image32(const Image32& rhs);
        ~Image32();
        void setBackground(const Color& background);
        const Color& getBackground() const;     
        const ImageData32& data() const;
        
        inline ImageData32& data() 
        {
            return data_;
        }
        
        inline const unsigned char* raw_data() const
        {
            return data_.getBytes();
        }
	
        inline unsigned char* raw_data()
        {
            return data_.getBytes();
        }
	
        void saveToFile(const std::string& file,const std::string& format="auto"); 
    private:

        inline bool checkBounds(unsigned x, unsigned y) const
        {
            return (x < width_ && y < height_);
        }

    public:
        inline void setPixel(int x,int y,unsigned int rgba)
        {
            if (checkBounds(x,y))
            {
                data_(x,y)=rgba;
            }
        }
        inline void blendPixel(int x,int y,unsigned int rgba1,int t)
        {
            if (checkBounds(x,y))
            {
                unsigned rgba0 = data_(x,y);	
                unsigned a1 = t;//(rgba1 >> 24) & 0xff;
                if (a1 == 0) return;
                unsigned r1 = rgba1 & 0xff;
                unsigned g1 = (rgba1 >> 8 ) & 0xff;
                unsigned b1 = (rgba1 >> 16) & 0xff;
		
                unsigned a0 = (rgba0 >> 24) & 0xff;
                unsigned r0 = (rgba0 & 0xff) * a0;
                unsigned g0 = ((rgba0 >> 8 ) & 0xff) * a0;
                unsigned b0 = ((rgba0 >> 16) & 0xff) * a0;
		
		
                a0 = ((a1 + a0) << 8) - a0*a1;
		
                r0 = ((((r1 << 8) - r0) * a1 + (r0 << 8)) / a0);
                g0 = ((((g1 << 8) - g0) * a1 + (g0 << 8)) / a0);
                b0 = ((((b1 << 8) - b0) * a1 + (b0 << 8)) / a0);
                a0 = a0 >> 8;
                data_(x,y)= (a0 << 24)| (b0 << 16) |  (g0 << 8) | (r0) ;
            }
        }

        inline unsigned width() const
        {
            return width_;
        }
	
        inline unsigned height() const
        {
            return height_;
        }

        inline void set_rectangle(int x0,int y0,ImageData32 const& data)
        {
            Envelope<int> ext0(0,0,width_,height_);   
            Envelope<int> ext1(x0,y0,x0+data.width(),y0+data.height());
	    
            if (ext0.intersects(ext1))
            {	
                Envelope<int> box = ext0.intersect(ext1);
                for (int y = box.miny(); y < box.maxy(); ++y)
                {
                    for (int x = box.minx(); x < box.maxx(); ++x)
                    {
                        if ((data(x-x0,y-y0) & 0xff000000)) 
                        {
                            data_(x,y)=data(x-x0,y-y0);
                        }
                    }
                }   
            }
        }
	
        inline void set_rectangle_alpha(int x0,int y0,const ImageData32& data)
        {
            Envelope<int> ext0(0,0,width_,height_);   
            Envelope<int> ext1(x0,y0,x0 + data.width(),y0 + data.height());
	    
            if (ext0.intersects(ext1))
            {	                		
                Envelope<int> box = ext0.intersect(ext1);		
                for (int y = box.miny(); y < box.maxy(); ++y)
                {
                    for (int x = box.minx(); x < box.maxx(); ++x)
                    {
                        unsigned rgba0 = data_(x,y);
                        unsigned rgba1 = data(x-x0,y-y0);
		    
                        unsigned a1 = (rgba1 >> 24) & 0xff;
                        if (a1 == 0) continue;
                        unsigned r1 = rgba1 & 0xff;
                        unsigned g1 = (rgba1 >> 8 ) & 0xff;
                        unsigned b1 = (rgba1 >> 16) & 0xff;
		    
                        unsigned a0 = (rgba0 >> 24) & 0xff;
                        unsigned r0 = (rgba0 & 0xff) * a0;
                        unsigned g0 = ((rgba0 >> 8 ) & 0xff) * a0;
                        unsigned b0 = ((rgba0 >> 16) & 0xff) * a0;
		    
		    
                        a0 = ((a1 + a0) << 8) - a0*a1;
		    
                        r0 = ((((r1 << 8) - r0) * a1 + (r0 << 8)) / a0);
                        g0 = ((((g1 << 8) - g0) * a1 + (g0 << 8)) / a0);
                        b0 = ((((b1 << 8) - b0) * a1 + (b0 << 8)) / a0);
                        a0 = a0 >> 8;
                        data_(x,y)= (a0 << 24)| (b0 << 16) |  (g0 << 8) | (r0) ;
                    }
                }
            }
        }
    };
}
#endif //GRAPHICS_HPP