1
2 //----------------------------------------------------------------------------
3 // Anti-Grain Geometry - Version 2.3
4 // Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
5 //
6 // Permission to copy, use, modify, sell and distribute this software
7 // is granted provided this copyright notice appears in all copies.
8 // This software is provided "as is" without express or implied
9 // warranty, and with no claim as to its suitability for any purpose.
10 //
11 //----------------------------------------------------------------------------
12 // Contact: mcseem@antigrain.com
13 // mcseemagg@yahoo.com
14 // http://www.antigrain.com
15 //----------------------------------------------------------------------------
16 // Bessel function (besj) was adapted for use in AGG library by Andy Wilk
17 // Contact: castor.vulgaris@gmail.com
18 //----------------------------------------------------------------------------
19 #ifndef AGG_MATH_INCLUDED
20 #define AGG_MATH_INCLUDED
21 #include "agg_basics.h"
22 namespace agg
23 {
24 const float intersection_epsilon = 1.0e-30f;
calc_point_location(float x1,float y1,float x2,float y2,float x,float y)25 AGG_INLINE float calc_point_location(float x1, float y1,
26 float x2, float y2,
27 float x, float y)
28 {
29 return ((x - x2) * (y2 - y1)) - ((y - y2) * (x2 - x1));
30 }
calc_distance(float x1,float y1,float x2,float y2)31 AGG_INLINE float calc_distance(float x1, float y1, float x2, float y2)
32 {
33 float dx = x2 - x1;
34 float dy = y2 - y1;
35 return FXSYS_sqrt2(dx, dy);
36 }
calc_line_point_distance(float x1,float y1,float x2,float y2,float x,float y)37 AGG_INLINE float calc_line_point_distance(float x1, float y1,
38 float x2, float y2,
39 float x, float y)
40 {
41 float dx = x2 - x1;
42 float dy = y2 - y1;
43 float d = FXSYS_sqrt2(dx, dy);
44 if(d < intersection_epsilon) {
45 return calc_distance(x1, y1, x, y);
46 }
47 return ((x - x2) * dy / d) - ((y - y2) * dx / d);
48 }
calc_intersection(float ax,float ay,float bx,float by,float cx,float cy,float dx,float dy,float * x,float * y)49 AGG_INLINE bool calc_intersection(float ax, float ay, float bx, float by,
50 float cx, float cy, float dx, float dy,
51 float* x, float* y)
52 {
53 float num = ((ay - cy) * (dx - cx)) - ((ax - cx) * (dy - cy));
54 float den = ((bx - ax) * (dy - cy)) - ((by - ay) * (dx - cx));
55 if (fabs(den) < intersection_epsilon) {
56 return false;
57 }
58 *x = ax + ((bx - ax) * num / den);
59 *y = ay + ((by - ay) * num / den);
60 return true;
61 }
62 }
63 #endif
64