xref: /haiku/src/libs/agg/src/agg_trans_double_path.cpp (revision 450f71e21e9565fda09170e7ac53ea16d5c241f5)
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_math.h"
17 #include "agg_trans_double_path.h"
18 
19 namespace agg
20 {
21 
22     //------------------------------------------------------------------------
trans_double_path()23     trans_double_path::trans_double_path() :
24         m_base_length(0.0),
25         m_base_height(1.0),
26         m_kindex1(0.0),
27         m_kindex2(0.0),
28         m_status1(initial),
29         m_status2(initial),
30         m_preserve_x_scale(true)
31     {
32     }
33 
34 
35         //------------------------------------------------------------------------
reset()36     void trans_double_path::reset()
37     {
38         m_src_vertices1.remove_all();
39         m_src_vertices2.remove_all();
40         m_kindex1 = 0.0;
41         m_kindex2 = 0.0;
42         m_status1 = initial;
43         m_status2 = initial;
44     }
45 
46 
47     //------------------------------------------------------------------------
move_to1(double x,double y)48     void trans_double_path::move_to1(double x, double y)
49     {
50         if(m_status1 == initial)
51         {
52             m_src_vertices1.modify_last(vertex_dist(x, y));
53             m_status1 = making_path;
54         }
55         else
56         {
57             line_to1(x, y);
58         }
59     }
60 
61 
62     //------------------------------------------------------------------------
line_to1(double x,double y)63     void trans_double_path::line_to1(double x, double y)
64     {
65         if(m_status1 == making_path)
66         {
67             m_src_vertices1.add(vertex_dist(x, y));
68         }
69     }
70 
71 
72     //------------------------------------------------------------------------
move_to2(double x,double y)73     void trans_double_path::move_to2(double x, double y)
74     {
75         if(m_status2 == initial)
76         {
77             m_src_vertices2.modify_last(vertex_dist(x, y));
78             m_status2 = making_path;
79         }
80         else
81         {
82             line_to2(x, y);
83         }
84     }
85 
86 
87     //------------------------------------------------------------------------
line_to2(double x,double y)88     void trans_double_path::line_to2(double x, double y)
89     {
90         if(m_status2 == making_path)
91         {
92             m_src_vertices2.add(vertex_dist(x, y));
93         }
94     }
95 
96 
97     //------------------------------------------------------------------------
finalize_path(vertex_storage & vertices)98     double trans_double_path::finalize_path(vertex_storage& vertices)
99     {
100         unsigned i;
101         double dist;
102         double d;
103 
104         vertices.close(false);
105         if(vertices.size() > 2)
106         {
107             if(vertices[vertices.size() - 2].dist * 10.0 <
108                vertices[vertices.size() - 3].dist)
109             {
110                 d = vertices[vertices.size() - 3].dist +
111                     vertices[vertices.size() - 2].dist;
112 
113                 vertices[vertices.size() - 2] =
114                     vertices[vertices.size() - 1];
115 
116                 vertices.remove_last();
117                 vertices[vertices.size() - 2].dist = d;
118             }
119         }
120 
121         dist = 0;
122         for(i = 0; i < vertices.size(); i++)
123         {
124             vertex_dist& v = vertices[i];
125             d = v.dist;
126             v.dist = dist;
127             dist += d;
128         }
129 
130         return (vertices.size() - 1) / dist;
131     }
132 
133 
134     //------------------------------------------------------------------------
finalize_paths()135     void trans_double_path::finalize_paths()
136     {
137         if(m_status1 == making_path && m_src_vertices1.size() > 1 &&
138            m_status2 == making_path && m_src_vertices2.size() > 1)
139         {
140             m_kindex1 = finalize_path(m_src_vertices1);
141             m_kindex2 = finalize_path(m_src_vertices2);
142             m_status1 = ready;
143             m_status2 = ready;
144         }
145     }
146 
147 
148     //------------------------------------------------------------------------
total_length1() const149     double trans_double_path::total_length1() const
150     {
151         if(m_base_length >= 1e-10) return m_base_length;
152         return (m_status1 == ready) ?
153             m_src_vertices1[m_src_vertices1.size() - 1].dist :
154             0.0;
155     }
156 
157 
158     //------------------------------------------------------------------------
total_length2() const159     double trans_double_path::total_length2() const
160     {
161         if(m_base_length >= 1e-10) return m_base_length;
162         return (m_status2 == ready) ?
163             m_src_vertices2[m_src_vertices2.size() - 1].dist :
164             0.0;
165     }
166 
167 
168     //------------------------------------------------------------------------
transform1(const vertex_storage & vertices,double kindex,double kx,double * x,double * y) const169     void trans_double_path::transform1(const vertex_storage& vertices,
170                                        double kindex, double kx,
171                                        double *x, double* y) const
172     {
173         double x1 = 0.0;
174         double y1 = 0.0;
175         double dx = 1.0;
176         double dy = 1.0;
177         double d  = 0.0;
178         double dd = 1.0;
179         *x *= kx;
180         if(*x < 0.0)
181         {
182             // Extrapolation on the left
183             //--------------------------
184             x1 = vertices[0].x;
185             y1 = vertices[0].y;
186             dx = vertices[1].x - x1;
187             dy = vertices[1].y - y1;
188             dd = vertices[1].dist - vertices[0].dist;
189             d  = *x;
190         }
191         else
192         if(*x > vertices[vertices.size() - 1].dist)
193         {
194             // Extrapolation on the right
195             //--------------------------
196             unsigned i = vertices.size() - 2;
197             unsigned j = vertices.size() - 1;
198             x1 = vertices[j].x;
199             y1 = vertices[j].y;
200             dx = x1 - vertices[i].x;
201             dy = y1 - vertices[i].y;
202             dd = vertices[j].dist - vertices[i].dist;
203             d  = *x - vertices[j].dist;
204         }
205         else
206         {
207             // Interpolation
208             //--------------------------
209             unsigned i = 0;
210             unsigned j = vertices.size() - 1;
211             if(m_preserve_x_scale)
212             {
213                 unsigned k;
214                 for(i = 0; (j - i) > 1; )
215                 {
216                     if(*x < vertices[k = (i + j) >> 1].dist)
217                     {
218                         j = k;
219                     }
220                     else
221                     {
222                         i = k;
223                     }
224                 }
225                 d  = vertices[i].dist;
226                 dd = vertices[j].dist - d;
227                 d  = *x - d;
228             }
229             else
230             {
231                 i = unsigned(*x * kindex);
232                 j = i + 1;
233                 dd = vertices[j].dist - vertices[i].dist;
234                 d = ((*x * kindex) - i) * dd;
235             }
236             x1 = vertices[i].x;
237             y1 = vertices[i].y;
238             dx = vertices[j].x - x1;
239             dy = vertices[j].y - y1;
240         }
241         *x = x1 + dx * d / dd;
242         *y = y1 + dy * d / dd;
243     }
244 
245 
246     //------------------------------------------------------------------------
transform(double * x,double * y) const247     void trans_double_path::transform(double *x, double *y) const
248     {
249         if(m_status1 == ready && m_status2 == ready)
250         {
251             if(m_base_length > 1e-10)
252             {
253                 *x *= m_src_vertices1[m_src_vertices1.size() - 1].dist /
254                       m_base_length;
255             }
256 
257             double x1 = *x;
258             double y1 = *y;
259             double x2 = *x;
260             double y2 = *y;
261             double dd = m_src_vertices2[m_src_vertices2.size() - 1].dist /
262                         m_src_vertices1[m_src_vertices1.size() - 1].dist;
263 
264             transform1(m_src_vertices1, m_kindex1, 1.0, &x1, &y1);
265             transform1(m_src_vertices2, m_kindex2, dd,  &x2, &y2);
266 
267             *x = x1 + *y * (x2 - x1) / m_base_height;
268             *y = y1 + *y * (y2 - y1) / m_base_height;
269         }
270     }
271 
272 }
273 
274