1 files changed, 158 insertions, 0 deletions
diff --git a/agg/inc/agg_bezier_arc.h b/agg/inc/agg_bezier_arc.h
new file mode 100755
index 000000000000..f437ab0a00bd
--- /dev/null
+++ b/agg/inc/agg_bezier_arc.h
@@ -0,0 +1,158 @@
+//----------------------------------------------------------------------------
+// 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
+//----------------------------------------------------------------------------
+//
+// 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) {}
+        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 : path_cmd_curve4;
+        }
+
+        // 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];
+    };
+
+
+
+    //==========================================================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