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"
22namespace agg
23{
24const FX_FLOAT intersection_epsilon = 1.0e-30f;
25AGG_INLINE FX_FLOAT calc_point_location(FX_FLOAT x1, FX_FLOAT y1,
26                                        FX_FLOAT x2, FX_FLOAT y2,
27                                        FX_FLOAT x,  FX_FLOAT y)
28{
29    return FXSYS_Mul(x - x2, y2 - y1) - FXSYS_Mul(y - y2, x2 - x1);
30}
31AGG_INLINE FX_FLOAT calc_distance(FX_FLOAT x1, FX_FLOAT y1, FX_FLOAT x2, FX_FLOAT y2)
32{
33    FX_FLOAT dx = x2 - x1;
34    FX_FLOAT dy = y2 - y1;
35    return FXSYS_sqrt2(dx, dy);
36}
37AGG_INLINE FX_FLOAT calc_line_point_distance(FX_FLOAT x1, FX_FLOAT y1,
38        FX_FLOAT x2, FX_FLOAT y2,
39        FX_FLOAT x,  FX_FLOAT y)
40{
41    FX_FLOAT dx = x2 - x1;
42    FX_FLOAT dy = y2 - y1;
43    FX_FLOAT d = FXSYS_sqrt2(dx, dy);
44    if(d < intersection_epsilon) {
45        return calc_distance(x1, y1, x, y);
46    }
47    return FXSYS_MulDiv(x - x2, dy, d) - FXSYS_MulDiv(y - y2, dx, d);
48}
49AGG_INLINE bool calc_intersection(FX_FLOAT ax, FX_FLOAT ay, FX_FLOAT bx, FX_FLOAT by,
50                                  FX_FLOAT cx, FX_FLOAT cy, FX_FLOAT dx, FX_FLOAT dy,
51                                  FX_FLOAT* x, FX_FLOAT* y)
52{
53    FX_FLOAT num = FXSYS_Mul(ay - cy, dx - cx) - FXSYS_Mul(ax - cx, dy - cy);
54    FX_FLOAT den = FXSYS_Mul(bx - ax, dy - cy) - FXSYS_Mul(by - ay, dx - cx);
55    if (FXSYS_fabs(den) < intersection_epsilon) {
56        return false;
57    }
58    *x = ax + FXSYS_MulDiv(bx - ax, num, den);
59    *y = ay + FXSYS_MulDiv(by - ay, num, den);
60    return true;
61}
62}
63#endif
64