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//----------------------------------------------------------------------------
// Anti-Grain Geometry - Version 2.4
// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
//
// Permission to copy, use, modify, sell and distribute this software
// is granted provided this copyright notice appears in all copies.
// This software is provided "as is" without express or implied
// warranty, and with no claim as to its suitability for any purpose.
//
//----------------------------------------------------------------------------
// Contact: mcseem@antigrain.com
// mcseemagg@yahoo.com
// http://www.antigrain.com
//----------------------------------------------------------------------------
//
// Arc generator. Produces at most 4 consecutive cubic bezier curves, i.e.,
// 4, 7, 10, or 13 vertices.
//
//----------------------------------------------------------------------------
#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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