/**
 * \file rasterize.h
 *
 * \brief Methoden um auf ein Canvas zu zeichnen
 *
 * Der rasterizer stellt Methoden zur verfügung um auf ein canvas zu
 * zeichnen. Darunter den Canvas zu leeren, Punkt, Linie, Polygon 
 * (gefüllt und ungefüllt) und Polyeder zeichnen und die Farbe
 * eines bestimmten Punktes im Zeichenpuffer ermitteln.
 * Diese Klasse ist abstrakt. Ein Rasterizer wird immer von einem
 * Canvas erzeugt werden, damit man einen zu diesem Canvas passenden
 * Rasteriser hat. Implementiert ist ein Software-Rasterizer zum zeichnen
 * auf ein X11 oder X11-shm Canvas.
 *
 * \author Georg Steffers <georg@steffers.org>
 *
 * \date 04.12.2003
 *
 * \version ..2002 (Georg Steffers): erste funktionierende Implementation
 * \version 04.12.2003 (Georg Steffers): beginn der Dokumentation via doxygen
 */ 

/* 
 * Copyright (C)2003 Georg Steffers
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * 
 * This program 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 General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#ifndef __rasterizer_h__
#define __rasterizer_h__

#include "canvas_imps/canvas_imp.h"
#include "geometry/polygon.h"
#include "geometry/polyeder.h"

class rasterizer {
    protected:
        unsigned x_size;
        unsigned y_size;

        canvas_imp* sinfo;

        vertex_list screen_p_vl;
        polygon screen_p;

        double** zbuf;

    public:
        rasterizer(unsigned = 0, unsigned = 0, canvas_imp* = NULL);

        virtual void clear_buffer(void) const=0;
        virtual void draw_point(unsigned x, unsigned y, 
                                unsigned long col) const=0;
        virtual void line(double, double, double, double, 
                          unsigned long) const=0;
        virtual void draw_polygon_flat(const polygon&, unsigned long) const=0;
        virtual void draw_polygon_wire(const polygon&, unsigned long) const=0;
        virtual void draw_polyeder_wire(const polyeder&, unsigned long) const=0;
        unsigned long get_color(unsigned red, unsigned green, unsigned blue) {
            return sinfo->ext_to_native(red, green, blue);
        }

        virtual unsigned get_x_size(void) const { return x_size; }
        virtual unsigned get_y_size(void) const { return y_size; }
};

class sw_rasterizer : public rasterizer {
    private:
        unsigned char* adr_of_point(unsigned, unsigned) const;
        void draw_point_at_paddress(unsigned char**, unsigned long) const;

    public:
        sw_rasterizer(unsigned xs, unsigned ys, canvas_imp* ci) :
            rasterizer(xs, ys, ci) {}

        void clear_buffer(void) const;
        void draw_point(unsigned x, unsigned y, unsigned long col) const;
        void line(double, double, double, double, unsigned long) const;
        void draw_polygon_flat(const polygon&, unsigned long) const;
        void draw_polygon_wire(const polygon&, unsigned long) const;
        void draw_polyeder_wire(const polyeder&, unsigned long) const;
};

#endif // __rasterize_h__