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/*
CLAW - a C++ Library Absolutely Wonderful
CLAW is a free library without any particular aim but being useful to
anyone.
Copyright (C) 2005-2011 Julien Jorge
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
contact: julien.jorge@gamned.org
*/
/**
* \file
* \brief Example program for the Bzier curves of Claw.
* \author Julien Jorge
*/
#include <claw/curve.hpp>
#include <claw/png.hpp>
#include <claw/string_algorithm.hpp>
#include <fstream>
#include <iostream>
typedef claw::math::coordinate_2d<double> coordinate_type;
typedef claw::math::curve<coordinate_type> curve_type;
/**
* \brief Read the points of a curve from a stream.
*
* The stream must describe the points in the following format:
* x y in_x in_y out_x out_y
*
* Where (x, y) is the coordinate of the control point, (in_x, in_y) is the
* coordinate of the direction of the curve when entering the point and
* (out_x, out_y) is the direction of the curve when leaving the point.
*
* If the in and out points are not set, they are set to (x, y) by default.
*
* \param c The curve to which the points are added.
* \param is The stream from which the curve is read.
*/
claw::math::coordinate_2d<std::size_t>
read_curve( curve_type& c, std::istream& is )
{
claw::math::coordinate_2d<std::size_t> max(0, 0);
std::string line;
while ( claw::text::getline( is, line ) )
{
std::istringstream iss(line);
coordinate_type position;
if ( iss >> position.x >> position.y )
{
max.x = std::max( (std::size_t)position.x, max.x );
max.y = std::max( (std::size_t)position.y, max.y );
coordinate_type in, out;
if ( iss >> in.x >> in.y >> out.x >> out.y )
c.push_back( curve_type::control_point(position, in, out) );
else
c.push_back( curve_type::control_point(position) );
}
}
return max;
} // read_curve()
/**
* \brief Draw the curve with a given precision.
* \param result The image in which the curve is drawn.
* \param c The curve to draw.
* \param step The step between two points of the curve.
*/
void draw_curve
( claw::graphic::image& result, const curve_type& c, double step )
{
for ( curve_type::const_iterator it=c.begin(); it!=c.end(); ++it )
{
const curve_type::section s( c.get_section(it) );
for ( double t(0); t<=1; t+=step )
{
const claw::math::coordinate_2d<int> p( s.get_point_at(t) );
if ( ( (0 <= p.x) && (p.x < (int)result.width()) )
&& ( (0 <= p.y) && (p.y < (int)result.height()) ) )
result[ p.y ][ p.x ] = claw::graphic::black_pixel;
}
}
} // draw_curve()
/**
* \brief Draw a curve in an image.
*/
int main( int argc, char* argv[] )
{
if ( argc != 2 )
{
std::cerr << "usage:\n"
<< '\t' << argv[0] << " step\n\n"
<< "The program reads the coordinates of the curve on stdin.\n"
<< "Each line represents a point in the following format:\n"
<< "\tx y input_x input_y output_x output_y\n"
<< "The curve is drawn in an image saved as output.png with a"
<< " detail of step.\n\n"
<< "example:\n"
<< "\tcat example | " << argv[0] << "0.001\n\n"
<< "where the content of example is:\n"
<< "0 0 0 0 75 25\n"
<< "50 75 75 75 25 75\n"
<< "100 0 25 25 100 0";
std::cerr << std::endl;
return 1;
}
double step(1);
std::istringstream iss(argv[1]);
iss >> step;
curve_type c;
claw::math::coordinate_2d<std::size_t> bounds = read_curve( c, std::cin );
claw::graphic::png result( bounds.x, bounds.y );
std::fill( result.begin(), result.end(), claw::graphic::white_pixel );
draw_curve( result, c, step );
std::ofstream f("output.png");
result.save( f );
return 0;
} // main()
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