xref: /haiku/src/libs/agg/src/agg_vpgen_clip_polyline.cpp (revision e39da397f5ff79f2db9f9a3ddf1852b6710578af)
1 //----------------------------------------------------------------------------
2 // Anti-Grain Geometry - Version 2.4
3 // Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
4 //
5 // Permission to copy, use, modify, sell and distribute this software
6 // is granted provided this copyright notice appears in all copies.
7 // This software is provided "as is" without express or implied
8 // warranty, and with no claim as to its suitability for any purpose.
9 //
10 //----------------------------------------------------------------------------
11 // Contact: mcseem@antigrain.com
12 //          mcseemagg@yahoo.com
13 //          http://www.antigrain.com
14 //----------------------------------------------------------------------------
15 
16 #include "agg_vpgen_clip_polyline.h"
17 #include "agg_clip_liang_barsky.h"
18 
19 namespace agg
20 {
21     //----------------------------------------------------------------------------
reset()22     void vpgen_clip_polyline::reset()
23     {
24         m_vertex = 0;
25         m_num_vertices = 0;
26         m_move_to = false;
27     }
28 
29     //----------------------------------------------------------------------------
move_to(double x,double y)30     void vpgen_clip_polyline::move_to(double x, double y)
31     {
32         m_vertex = 0;
33         m_num_vertices = 0;
34         m_x1 = x;
35         m_y1 = y;
36         m_move_to = true;
37     }
38 
39     //----------------------------------------------------------------------------
line_to(double x,double y)40     void vpgen_clip_polyline::line_to(double x, double y)
41     {
42         double x2 = x;
43         double y2 = y;
44         unsigned flags = clip_line_segment(&m_x1, &m_y1, &x2, &y2, m_clip_box);
45 
46         m_vertex = 0;
47         m_num_vertices = 0;
48         if((flags & 4) == 0)
49         {
50             if((flags & 1) != 0 || m_move_to)
51             {
52                 m_x[0] = m_x1;
53                 m_y[0] = m_y1;
54                 m_cmd[0] = path_cmd_move_to;
55                 m_num_vertices = 1;
56             }
57             m_x[m_num_vertices] = x2;
58             m_y[m_num_vertices] = y2;
59             m_cmd[m_num_vertices++] = path_cmd_line_to;
60             m_move_to = (flags & 2) != 0;
61         }
62         m_x1 = x;
63         m_y1 = y;
64     }
65 
66     //----------------------------------------------------------------------------
vertex(double * x,double * y)67     unsigned vpgen_clip_polyline::vertex(double* x, double* y)
68     {
69         if(m_vertex < m_num_vertices)
70         {
71             *x = m_x[m_vertex];
72             *y = m_y[m_vertex];
73             return m_cmd[m_vertex++];
74         }
75         return path_cmd_stop;
76     }
77 }
78