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+//----------------------------------------------------------------------------
+// Anti-Grain Geometry - Version 2.3
+// 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
+//----------------------------------------------------------------------------
+//
+// class ellipse
+//
+//----------------------------------------------------------------------------
+
+#ifndef AGG_ELLIPSE_INCLUDED
+#define AGG_ELLIPSE_INCLUDED
+
+#include "agg_basics.h"
+#include <math.h>
+
+namespace agg
+{
+
+ //----------------------------------------------------------------ellipse
+ class ellipse
+ {
+ public:
+ ellipse() : m_x(0.0), m_y(0.0), m_rx(1.0), m_ry(1.0), m_num(4), m_step(0) {}
+ ellipse(double x, double y, double rx, double ry, unsigned num_steps)
+ : m_x(x), m_y(y), m_rx(rx), m_ry(ry), m_num(num_steps), m_step(0) {}
+
+ void init(double x, double y, double rx, double ry, unsigned num_steps);
+ void approximation_scale(double scale);
+ void rewind(unsigned id);
+ unsigned vertex(double* x, double* y);
+
+ private:
+ double m_x;
+ double m_y;
+ double m_rx;
+ double m_ry;
+ unsigned m_num;
+ unsigned m_step;
+ };
+
+
+ //------------------------------------------------------------------------
+ inline void ellipse::init(double x, double y, double rx, double ry, unsigned num_steps)
+ {
+ m_x = x;
+ m_y = y;
+ m_rx = rx;
+ m_ry = ry;
+ m_num = num_steps;
+ m_step = 0;
+ }
+
+ //------------------------------------------------------------------------
+ inline void ellipse::approximation_scale(double scale)
+ {
+ m_num = unsigned((fabs(m_rx) + fabs(m_ry) + 6.0) * scale);
+ if(m_num < 6) m_num = 6;
+ }
+
+ //------------------------------------------------------------------------
+ inline void ellipse::rewind(unsigned)
+ {
+ m_step = 0;
+ }
+
+ //------------------------------------------------------------------------
+ inline unsigned ellipse::vertex(double* x, double* y)
+ {
+ if(m_step == m_num)
+ {
+ ++m_step;
+ return path_cmd_end_poly | path_flags_close | path_flags_ccw;
+ }
+ if(m_step > m_num) return path_cmd_stop;
+ double angle = double(m_step) / double(m_num) * 2.0 * pi;
+ *x = m_x + cos(angle) * m_rx;
+ *y = m_y + sin(angle) * m_ry;
+ m_step++;
+ return ((m_step == 1) ? path_cmd_move_to : path_cmd_line_to);
+ }
+
+}
+
+
+
+#endif
+
+