1 2 //---------------------------------------------------------------------------- 3 // XYQ: 2006-01-22 Copied from AGG project. 4 // TODO: This file uses intensive floating point operations, so it's NOT suitable 5 // for platforms like Symbian OS. We need to change to FIX format. 6 //---------------------------------------------------------------------------- 7 //---------------------------------------------------------------------------- 8 // Anti-Grain Geometry - Version 2.3 9 // Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com) 10 // 11 // Permission to copy, use, modify, sell and distribute this software 12 // is granted provided this copyright notice appears in all copies. 13 // This software is provided "as is" without express or implied 14 // warranty, and with no claim as to its suitability for any purpose. 15 // 16 //---------------------------------------------------------------------------- 17 // Contact: mcseem (at) antigrain.com 18 // mcseemagg (at) yahoo.com 19 // http://www.antigrain.com 20 //---------------------------------------------------------------------------- 21 22 #include "agg_curves.h" 23 #include "agg_math.h" 24 25 namespace agg 26 { 27 const float curve_collinearity_epsilon = 1e-30f; 28 enum curve_recursion_limit_e { curve_recursion_limit = 16 }; 29 void curve4_div::init(float x1, float y1, 30 float x2, float y2, 31 float x3, float y3, 32 float x4, float y4) 33 { 34 m_points.remove_all(); 35 m_distance_tolerance_square = 1.0f / 4; 36 m_distance_tolerance_manhattan = 1.0f * 4; 37 bezier(x1, y1, x2, y2, x3, y3, x4, y4); 38 m_count = 0; 39 } 40 void curve4_div::recursive_bezier(float x1, float y1, 41 float x2, float y2, 42 float x3, float y3, 43 float x4, float y4, 44 unsigned level) 45 { 46 if(level > curve_recursion_limit) { 47 return; 48 } 49 float x12 = (x1 + x2) / 2; 50 float y12 = (y1 + y2) / 2; 51 float x23 = (x2 + x3) / 2; 52 float y23 = (y2 + y3) / 2; 53 float x34 = (x3 + x4) / 2; 54 float y34 = (y3 + y4) / 2; 55 float x123 = (x12 + x23) / 2; 56 float y123 = (y12 + y23) / 2; 57 float x234 = (x23 + x34) / 2; 58 float y234 = (y23 + y34) / 2; 59 float x1234 = (x123 + x234) / 2; 60 float y1234 = (y123 + y234) / 2; 61 float dx = x4 - x1; 62 float dy = y4 - y1; 63 float d2 = fabs(((x2 - x4) * dy) - ((y2 - y4) * dx)); 64 float d3 = fabs(((x3 - x4) * dy) - ((y3 - y4) * dx)); 65 switch((int(d2 > curve_collinearity_epsilon) << 1) + 66 int(d3 > curve_collinearity_epsilon)) { 67 case 0: 68 if (fabs(x1 + x3 - x2 - x2) + fabs(y1 + y3 - y2 - y2) + 69 fabs(x2 + x4 - x3 - x3) + fabs(y2 + y4 - y3 - y3) <= 70 m_distance_tolerance_manhattan) { 71 m_points.add(point_type(x1234, y1234, path_flags_jr)); 72 return; 73 } 74 break; 75 case 1: 76 if ((d3 * d3) <= 77 (m_distance_tolerance_square * ((dx * dx) + (dy * dy)))) { 78 m_points.add(point_type(x23, y23, path_flags_jr)); 79 return; 80 } 81 break; 82 case 2: 83 if ((d2 * d2) <= 84 (m_distance_tolerance_square * ((dx * dx) + (dy * dy)))) { 85 m_points.add(point_type(x23, y23, path_flags_jr)); 86 return; 87 } 88 break; 89 case 3: 90 if (((d2 + d3) * (d2 + d3)) <= 91 (m_distance_tolerance_square * ((dx * dx) + (dy * dy)))) { 92 m_points.add(point_type(x23, y23, path_flags_jr)); 93 return; 94 } 95 break; 96 } 97 recursive_bezier(x1, y1, x12, y12, x123, y123, x1234, y1234, level + 1); 98 recursive_bezier(x1234, y1234, x234, y234, x34, y34, x4, y4, level + 1); 99 } 100 void curve4_div::bezier(float x1, float y1, 101 float x2, float y2, 102 float x3, float y3, 103 float x4, float y4) 104 { 105 m_points.add(point_type(x1, y1)); 106 recursive_bezier(x1, y1, x2, y2, x3, y3, x4, y4, 0); 107 m_points.add(point_type(x4, y4)); 108 } 109 } 110
