Anti-Grain Geometry Tutorial
agg_arrowhead.cpp
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 // Simple arrowhead/arrowtail generator
17 //
18 //----------------------------------------------------------------------------
19 
20 #include "agg_arrowhead.h"
21 
22 namespace agg
23 {
24 
25  //------------------------------------------------------------------------
26  arrowhead::arrowhead() :
27  m_head_d1(1.0),
28  m_head_d2(1.0),
29  m_head_d3(1.0),
30  m_head_d4(0.0),
31  m_tail_d1(1.0),
32  m_tail_d2(1.0),
33  m_tail_d3(1.0),
34  m_tail_d4(0.0),
35  m_head_flag(false),
36  m_tail_flag(false),
37  m_curr_id(0),
38  m_curr_coord(0)
39  {
40  }
41 
42 
43 
44  //------------------------------------------------------------------------
45  void arrowhead::rewind(unsigned path_id)
46  {
47  m_curr_id = path_id;
48  m_curr_coord = 0;
49  if(path_id == 0)
50  {
51  if(!m_tail_flag)
52  {
53  m_cmd[0] = path_cmd_stop;
54  return;
55  }
56  m_coord[0] = m_tail_d1; m_coord[1] = 0.0;
57  m_coord[2] = m_tail_d1 - m_tail_d4; m_coord[3] = m_tail_d3;
58  m_coord[4] = -m_tail_d2 - m_tail_d4; m_coord[5] = m_tail_d3;
59  m_coord[6] = -m_tail_d2; m_coord[7] = 0.0;
60  m_coord[8] = -m_tail_d2 - m_tail_d4; m_coord[9] = -m_tail_d3;
61  m_coord[10] = m_tail_d1 - m_tail_d4; m_coord[11] = -m_tail_d3;
62 
63  m_cmd[0] = path_cmd_move_to;
64  m_cmd[1] = path_cmd_line_to;
65  m_cmd[2] = path_cmd_line_to;
66  m_cmd[3] = path_cmd_line_to;
67  m_cmd[4] = path_cmd_line_to;
68  m_cmd[5] = path_cmd_line_to;
69  m_cmd[7] = path_cmd_end_poly | path_flags_close | path_flags_ccw;
70  m_cmd[6] = path_cmd_stop;
71  return;
72  }
73 
74  if(path_id == 1)
75  {
76  if(!m_head_flag)
77  {
78  m_cmd[0] = path_cmd_stop;
79  return;
80  }
81  m_coord[0] = -m_head_d1; m_coord[1] = 0.0;
82  m_coord[2] = m_head_d2 + m_head_d4; m_coord[3] = -m_head_d3;
83  m_coord[4] = m_head_d2; m_coord[5] = 0.0;
84  m_coord[6] = m_head_d2 + m_head_d4; m_coord[7] = m_head_d3;
85 
86  m_cmd[0] = path_cmd_move_to;
87  m_cmd[1] = path_cmd_line_to;
88  m_cmd[2] = path_cmd_line_to;
89  m_cmd[3] = path_cmd_line_to;
90  m_cmd[4] = path_cmd_end_poly | path_flags_close | path_flags_ccw;
91  m_cmd[5] = path_cmd_stop;
92  return;
93  }
94  }
95 
96 
97  //------------------------------------------------------------------------
98  unsigned arrowhead::vertex(double* x, double* y)
99  {
100  if(m_curr_id < 2)
101  {
102  unsigned curr_idx = m_curr_coord * 2;
103  *x = m_coord[curr_idx];
104  *y = m_coord[curr_idx + 1];
105  return m_cmd[m_curr_coord++];
106  }
107  return path_cmd_stop;
108  }
109 
110 }
agg
Definition: agg_arc.cpp:24