123 lines
3.2 KiB
C++
123 lines
3.2 KiB
C++
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/* This file is part of Mapnik (c++ mapping toolkit)
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* Copyright (C) 2005 Artem Pavlenko
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*
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* Mapnik is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*/
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//$Id: ctrans.hpp 39 2005-04-10 20:39:53Z pavlenko $
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#ifndef CTRANS_HPP
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#define CTRANS_HPP
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#include "envelope.hpp"
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#include "coord_array.hpp"
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namespace mapnik
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{
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typedef coord_array<coord2d> CoordinateArray;
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class CoordTransform
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{
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private:
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int width;
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int height;
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double scale_;
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Envelope<double> extent;
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coord2d center_;
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public:
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CoordTransform(int width,int height,const Envelope<double>& extent)
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:width(width),height(height),extent(extent),center_(extent.center())
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{
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double sx=((double)width)/extent.width();
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double sy=((double)height)/extent.height();
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scale_=std::min(sx,sy);
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}
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inline double scale() const
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{
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return scale_;
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}
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double forward_x(double x) const
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{
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return (x-center_.x)*scale_+0.5*width;
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}
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double forward_y(double y) const
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{
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return -(y-center_.y)*scale_+0.5*height;
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}
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inline coord2d& forward(coord2d& c) const
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{
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c.x=(c.x-center_.x)*scale_+0.5*width;
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c.y=-(c.y-center_.y)*scale_+0.5*height;
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return c;
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}
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inline coord2d& backward(coord2d& c) const
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{
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c.x=(c.x-0.5*width)/scale_+center_.x;
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c.y=-(c.y-0.5*height)/scale_+center_.y;
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return c;
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}
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inline Envelope<double> forward(const Envelope<double>& e) const
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{
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double x0=(e.minx()-center_.x)*scale_+0.5*width;
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double x1=(e.maxx()-center_.x)*scale_+0.5*width;
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double y0=-(e.miny()-center_.y)*scale_+0.5*height;
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double y1=-(e.maxy()-center_.y)*scale_+0.5*height;
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return Envelope<double>(x0,y0,x1,y1);
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}
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inline Envelope<double> backward(const Envelope<double>& e) const
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{
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double x0=(e.minx()-0.5*width)/scale_+center_.x;
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double x1=(e.maxx()-0.5*width)/scale_+center_.x;
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double y0=-(e.miny()-0.5*height)/scale_+center_.y;
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double y1=-(e.maxy()-0.5*height)/scale_+center_.y;
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return Envelope<double>(x0,y0,x1,y1);
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}
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inline CoordinateArray& forward(CoordinateArray& coords) const
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{
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for (unsigned i=0;i<coords.size();++i)
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{
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coords[i].x=(coords[i].x-center_.x)*scale_+0.5*width;
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coords[i].y=-(coords[i].y-center_.y)*scale_+0.5*height;
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}
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return coords;
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}
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inline CoordinateArray& backward(CoordinateArray& coords) const
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{
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for (unsigned i=0;i<coords.size();++i)
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{
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coords[i].x=(coords[i].x-0.5*width)/scale_+center_.x;
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coords[i].y=-(coords[i].y-0.5*height)/scale_+center_.y;
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}
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return coords;
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}
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};
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}
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#endif //CTRANS_HPP
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