drawtile.cpp

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/*
    ParaGUI - crossplatform widgetset
    drawtile - draw tiles onto surfaces
 
    Copyright (C) 2000,2001,2002  Alexander Pipelka
 
    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 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
    Library General Public License for more details.
 
    You should have received a copy of the GNU Library General Public
    License along with this library; if not, write to the Free
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 
    Alexander Pipelka
    pipelka@teleweb.at
 
    Last Update:      $Author: mbickel $
    Update Date:      $Date: 2007-04-13 16:16:00 $
    Source File:      $Source: /home/cvspsrv/cvsroot/games/asc/source/libs/paragui/src/draw/drawtile.cpp,v $
    CVS/RCS Revision: $Revision: 1.2 $
    Status:           $State: Exp $
*/

#include "pgdraw.h"
#include <cmath>

void PG_Draw::DrawTile(SDL_Surface* surface, const PG_Rect& ref, const PG_Rect& drawrect, SDL_Surface* tilemap) {
        PG_Point index1;
        PG_Point index2;
        PG_Rect oldclip;

        if (!surface || !tilemap) {
                return;
        }

        if (!tilemap->w || !tilemap->h || !surface->w || !surface->h) {
                return;
        }

        int dx = (int)std::abs((double)(drawrect.x - ref.x));
        int dy = (int)std::abs((double)(drawrect.y - ref.y));

        index1.x = dx / tilemap->w;
        index1.y = dy / tilemap->h;

        index2.x = (dx + drawrect.w + tilemap->w - 1) / tilemap->w;
        index2.y = (dy + drawrect.h + tilemap->h - 1) / tilemap->h;

        SDL_GetClipRect(surface, const_cast<PG_Rect*>(&oldclip));
        SDL_SetClipRect(surface, const_cast<PG_Rect*>(&drawrect));

        PG_Rect src(0,0, tilemap->w, tilemap->h);
        PG_Rect dst = src;

        for(int y = index1.y; y < index2.y; y++) {
                for(int x = index1.x; x < index2.x; x++) {

                        dst.x = ref.x + x * tilemap->w;
                        dst.y = ref.y + y * tilemap->h;

                        PG_Draw::BlitSurface(tilemap, src, surface, dst);
                }
        }

        SDL_SetClipRect(surface, const_cast<PG_Rect*>(&oldclip));
}

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