libs/agg/agg_math.h

38                                     double x2, double y2,
41         return (x - x2) * (y2 - y1) - (y - y2) * (x2 - x1);
46                                       double x2, double y2,
50         bool cp1 = cross_product(x1, y1, x2, y2, x, y) < 0.0;
51         bool cp2 = cross_product(x2, y2, x3, y3, x, y) < 0.0;
57     AGG_INLINE double calc_distance(double x1, double y1, double x2, double y2)
60         double dy = y2-y1;
65     AGG_INLINE double calc_sq_distance(double x1, double y1, double x2, double y2)
68         double dy = y2-y1;
74                                                double x2, double y2,
78         double dy = y2-y1;
84         return ((x - x2) * dy - (y - y2) * dx) / d;
89                                            double x2, double y2,
93         double dy = y2 - y1;
108                                                      double x2, double y2,
119 	        return calc_sq_distance(x, y, x2, y2);
121         return calc_sq_distance(x, y, x1 + u * (x2 - x1), y1 + u * (y2 - y1));
126                                                      double x2, double y2,
131                 x1, y1, x2, y2, x, y,
132                 calc_segment_point_u(x1, y1, x2, y2, x, y));
150     AGG_INLINE bool intersection_exists(double x1, double y1, double x2, double y2,
156         double dy1 = y2 - y1;
159         return ((x3 - x2) * dy1 - (y3 - y2) * dx1 < 0.0) !=
160                ((x4 - x2) * dy1 - (y4 - y2) * dx1 < 0.0) &&
162                ((x2 - x4) * dy2 - (y2 - y4) * dx2 < 0.0);
167         //double den  = (x2-x1) * (y4-y3) - (y2-y1) * (x4-x3);
170         //double nom2 = (x2-x1) * (y1-y3) - (y2-y1) * (x1-x3);
179                                     double x2, double y2,
183         double dy = y2 - y1;
191                                     double x2, double y2,
202         double loc = cross_product(x1, y1, x2, y2, x3, y3);
205             if(cross_product(x1, y1, x2, y2, x3, y3) > 0.0)
209             calc_orthogonal(d, x1, y1, x2, y2, &dx1, &dy1);
210             calc_orthogonal(d, x2, y2, x3, y3, &dx2, &dy2);
214         *x++ = x2 + dx1;  *y++ = y2 + dy1;
215         *x++ = x2 + dx2;  *y++ = y2 + dy2;
223                                          double x2, double y2,
226         return (x1*y2 - x2*y1 + x2*y3 - x3*y2 + x3*y1 - x1*y3) * 0.5;