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//----------------------------------------------------------------------------
// Anti-Grain Geometry (AGG) - Version 2.5
// A high quality rendering engine for C++
// Copyright (C) 2002-2006 Maxim Shemanarev
// Contact: mcseem@antigrain.com
// mcseemagg@yahoo.com
// http://antigrain.com
//
// AGG 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.
//
// AGG 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 AGG; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
// MA 02110-1301, USA.
//----------------------------------------------------------------------------
#ifndef AGG_BEZIER_ARC_INCLUDED
#define AGG_BEZIER_ARC_INCLUDED
#include "agg_conv_transform.h"
namespace agg
{
//-----------------------------------------------------------------------
void arc_to_bezier(double cx, double cy, double rx, double ry,
double start_angle, double sweep_angle,
double* curve);
//==============================================================bezier_arc
//
// See implemantaion agg_bezier_arc.cpp
//
class bezier_arc
{
public:
//--------------------------------------------------------------------
bezier_arc() : m_vertex(26), m_num_vertices(0), m_cmd(path_cmd_line_to) {}
bezier_arc(double x, double y,
double rx, double ry,
double start_angle,
double sweep_angle)
{
init(x, y, rx, ry, start_angle, sweep_angle);
}
//--------------------------------------------------------------------
void init(double x, double y,
double rx, double ry,
double start_angle,
double sweep_angle);
//--------------------------------------------------------------------
void rewind(unsigned)
{
m_vertex = 0;
}
//--------------------------------------------------------------------
unsigned vertex(double* x, double* y)
{
if(m_vertex >= m_num_vertices) return path_cmd_stop;
*x = m_vertices[m_vertex];
*y = m_vertices[m_vertex + 1];
m_vertex += 2;
return (m_vertex == 2) ? path_cmd_move_to : m_cmd;
}
// Supplemantary functions. num_vertices() actually returns doubled
// number of vertices. That is, for 1 vertex it returns 2.
//--------------------------------------------------------------------
unsigned num_vertices() const { return m_num_vertices; }
const double* vertices() const { return m_vertices; }
double* vertices() { return m_vertices; }
private:
unsigned m_vertex;
unsigned m_num_vertices;
double m_vertices[26];
unsigned m_cmd;
};
//==========================================================bezier_arc_svg
// Compute an SVG-style bezier arc.
//
// Computes an elliptical arc from (x1, y1) to (x2, y2). The size and
// orientation of the ellipse are defined by two radii (rx, ry)
// and an x-axis-rotation, which indicates how the ellipse as a whole
// is rotated relative to the current coordinate system. The center
// (cx, cy) of the ellipse is calculated automatically to satisfy the
// constraints imposed by the other parameters.
// large-arc-flag and sweep-flag contribute to the automatic calculations
// and help determine how the arc is drawn.
class bezier_arc_svg
{
public:
//--------------------------------------------------------------------
bezier_arc_svg() : m_arc(), m_radii_ok(false) {}
bezier_arc_svg(double x1, double y1,
double rx, double ry,
double angle,
bool large_arc_flag,
bool sweep_flag,
double x2, double y2) :
m_arc(), m_radii_ok(false)
{
init(x1, y1, rx, ry, angle, large_arc_flag, sweep_flag, x2, y2);
}
//--------------------------------------------------------------------
void init(double x1, double y1,
double rx, double ry,
double angle,
bool large_arc_flag,
bool sweep_flag,
double x2, double y2);
//--------------------------------------------------------------------
bool radii_ok() const { return m_radii_ok; }
//--------------------------------------------------------------------
void rewind(unsigned)
{
m_arc.rewind(0);
}
//--------------------------------------------------------------------
unsigned vertex(double* x, double* y)
{
return m_arc.vertex(x, y);
}
// Supplemantary functions. num_vertices() actually returns doubled
// number of vertices. That is, for 1 vertex it returns 2.
//--------------------------------------------------------------------
unsigned num_vertices() const { return m_arc.num_vertices(); }
const double* vertices() const { return m_arc.vertices(); }
double* vertices() { return m_arc.vertices(); }
private:
bezier_arc m_arc;
bool m_radii_ok;
};
}
#endif
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