| |
| //---------------------------------------------------------------------------- |
| // 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 |
| //---------------------------------------------------------------------------- |
| // Bessel function (besj) was adapted for use in AGG library by Andy Wilk |
| // Contact: castor.vulgaris@gmail.com |
| //---------------------------------------------------------------------------- |
| #ifndef AGG_MATH_INCLUDED |
| #define AGG_MATH_INCLUDED |
| #include "agg_basics.h" |
| namespace agg |
| { |
| const float intersection_epsilon = 1.0e-30f; |
| AGG_INLINE float calc_point_location(float x1, float y1, |
| float x2, float y2, |
| float x, float y) |
| { |
| return ((x - x2) * (y2 - y1)) - ((y - y2) * (x2 - x1)); |
| } |
| AGG_INLINE float calc_distance(float x1, float y1, float x2, float y2) |
| { |
| float dx = x2 - x1; |
| float dy = y2 - y1; |
| return FXSYS_sqrt2(dx, dy); |
| } |
| AGG_INLINE float calc_line_point_distance(float x1, float y1, |
| float x2, float y2, |
| float x, float y) |
| { |
| float dx = x2 - x1; |
| float dy = y2 - y1; |
| float d = FXSYS_sqrt2(dx, dy); |
| if(d < intersection_epsilon) { |
| return calc_distance(x1, y1, x, y); |
| } |
| return ((x - x2) * dy / d) - ((y - y2) * dx / d); |
| } |
| AGG_INLINE bool calc_intersection(float ax, float ay, float bx, float by, |
| float cx, float cy, float dx, float dy, |
| float* x, float* y) |
| { |
| float num = ((ay - cy) * (dx - cx)) - ((ax - cx) * (dy - cy)); |
| float den = ((bx - ax) * (dy - cy)) - ((by - ay) * (dx - cx)); |
| if (fabs(den) < intersection_epsilon) { |
| return false; |
| } |
| *x = ax + ((bx - ax) * num / den); |
| *y = ay + ((by - ay) * num / den); |
| return true; |
| } |
| } |
| #endif |
