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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
+//----------------------------------------------------------------------------
+
+#include <math.h>
+#include "agg_line_aa_basics.h"
+
+namespace agg
+{
+ //-------------------------------------------------------------------------
+ // The number of the octant is determined as a 3-bit value as follows:
+ // bit 0 = vertical flag
+ // bit 1 = sx < 0
+ // bit 2 = sy < 0
+ //
+ // [N] shows the number of the orthogonal quadrant
+ // <M> shows the number of the diagonal quadrant
+ // <1>
+ // [1] | [0]
+ // . (3)011 | 001(1) .
+ // . | .
+ // . | .
+ // . | .
+ // (2)010 .|. 000(0)
+ // <2> ----------.+.----------- <0>
+ // (6)110 . | . 100(4)
+ // . | .
+ // . | .
+ // . | .
+ // (7)111 | 101(5)
+ // [2] | [3]
+ // <3>
+ // 0,1,2,3,4,5,6,7
+ int8u line_parameters::s_orthogonal_quadrant[8] = { 0,0,1,1,3,3,2,2 };
+ int8u line_parameters::s_diagonal_quadrant[8] = { 0,1,2,1,0,3,2,3 };
+
+
+
+ //-------------------------------------------------------------------------
+ void bisectrix(const line_parameters& l1,
+ const line_parameters& l2,
+ int* x, int* y)
+ {
+ double k = double(l2.len) / double(l1.len);
+ double tx = l2.x2 - (l2.x1 - l1.x1) * k;
+ double ty = l2.y2 - (l2.y1 - l1.y1) * k;
+
+ //All bisectrices must be on the right of the line
+ //If the next point is on the left (l1 => l2.2)
+ //then the bisectix should be rotated by 180 degrees.
+ if(double(l2.x2 - l2.x1) * double(l2.y1 - l1.y1) <
+ double(l2.y2 - l2.y1) * double(l2.x1 - l1.x1) + 100.0)
+ {
+ tx -= (tx - l2.x1) * 2.0;
+ ty -= (ty - l2.y1) * 2.0;
+ }
+
+ // Check if the bisectrix is too short
+ double dx = tx - l2.x1;
+ double dy = ty - l2.y1;
+ if((int)sqrt(dx * dx + dy * dy) < line_subpixel_size)
+ {
+ *x = (l2.x1 + l2.x1 + (l2.y1 - l1.y1) + (l2.y2 - l2.y1)) >> 1;
+ *y = (l2.y1 + l2.y1 - (l2.x1 - l1.x1) - (l2.x2 - l2.x1)) >> 1;
+ return;
+ }
+ *x = int(tx);
+ *y = int(ty);
+ }
+
+}