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 #include "core/fxcrt/fx_basic.h" 25 26 namespace agg 27 { 28 const FX_FLOAT curve_collinearity_epsilon = 1e-30f; 29 enum curve_recursion_limit_e { curve_recursion_limit = 16 }; 30 void curve4_div::init(FX_FLOAT x1, FX_FLOAT y1, 31 FX_FLOAT x2, FX_FLOAT y2, 32 FX_FLOAT x3, FX_FLOAT y3, 33 FX_FLOAT x4, FX_FLOAT y4) 34 { 35 m_points.remove_all(); 36 m_distance_tolerance_square = 1.0f / 4; 37 m_distance_tolerance_manhattan = 1.0f * 4; 38 bezier(x1, y1, x2, y2, x3, y3, x4, y4); 39 m_count = 0; 40 } 41 void curve4_div::recursive_bezier(FX_FLOAT x1, FX_FLOAT y1, 42 FX_FLOAT x2, FX_FLOAT y2, 43 FX_FLOAT x3, FX_FLOAT y3, 44 FX_FLOAT x4, FX_FLOAT y4, 45 unsigned level) 46 { 47 if(level > curve_recursion_limit) { 48 return; 49 } 50 FX_FLOAT x12 = (x1 + x2) / 2; 51 FX_FLOAT y12 = (y1 + y2) / 2; 52 FX_FLOAT x23 = (x2 + x3) / 2; 53 FX_FLOAT y23 = (y2 + y3) / 2; 54 FX_FLOAT x34 = (x3 + x4) / 2; 55 FX_FLOAT y34 = (y3 + y4) / 2; 56 FX_FLOAT x123 = (x12 + x23) / 2; 57 FX_FLOAT y123 = (y12 + y23) / 2; 58 FX_FLOAT x234 = (x23 + x34) / 2; 59 FX_FLOAT y234 = (y23 + y34) / 2; 60 FX_FLOAT x1234 = (x123 + x234) / 2; 61 FX_FLOAT y1234 = (y123 + y234) / 2; 62 FX_FLOAT dx = x4 - x1; 63 FX_FLOAT dy = y4 - y1; 64 FX_FLOAT d2 = FXSYS_fabs(((x2 - x4) * dy) - ((y2 - y4) * dx)); 65 FX_FLOAT d3 = FXSYS_fabs(((x3 - x4) * dy) - ((y3 - y4) * dx)); 66 switch((int(d2 > curve_collinearity_epsilon) << 1) + 67 int(d3 > curve_collinearity_epsilon)) { 68 case 0: 69 if(FXSYS_fabs(x1 + x3 - x2 - x2) + 70 FXSYS_fabs(y1 + y3 - y2 - y2) + 71 FXSYS_fabs(x2 + x4 - x3 - x3) + 72 FXSYS_fabs(y2 + y4 - y3 - y3) <= m_distance_tolerance_manhattan) { 73 m_points.add(point_type(x1234, y1234, path_flags_jr)); 74 return; 75 } 76 break; 77 case 1: 78 if ((d3 * d3) <= 79 (m_distance_tolerance_square * ((dx * dx) + (dy * dy)))) { 80 m_points.add(point_type(x23, y23, path_flags_jr)); 81 return; 82 } 83 break; 84 case 2: 85 if ((d2 * d2) <= 86 (m_distance_tolerance_square * ((dx * dx) + (dy * dy)))) { 87 m_points.add(point_type(x23, y23, path_flags_jr)); 88 return; 89 } 90 break; 91 case 3: 92 if (((d2 + d3) * (d2 + d3)) <= 93 (m_distance_tolerance_square * ((dx * dx) + (dy * dy)))) { 94 m_points.add(point_type(x23, y23, path_flags_jr)); 95 return; 96 } 97 break; 98 } 99 recursive_bezier(x1, y1, x12, y12, x123, y123, x1234, y1234, level + 1); 100 recursive_bezier(x1234, y1234, x234, y234, x34, y34, x4, y4, level + 1); 101 } 102 void curve4_div::bezier(FX_FLOAT x1, FX_FLOAT y1, 103 FX_FLOAT x2, FX_FLOAT y2, 104 FX_FLOAT x3, FX_FLOAT y3, 105 FX_FLOAT x4, FX_FLOAT y4) 106 { 107 m_points.add(point_type(x1, y1)); 108 recursive_bezier(x1, y1, x2, y2, x3, y3, x4, y4, 0); 109 m_points.add(point_type(x4, y4)); 110 } 111 } 112
