1/**************************************************************************
2 *
3 * Copyright 2009 VMware, Inc.  All Rights Reserved.
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the
7 * "Software"), to deal in the Software without restriction, including
8 * without limitation the rights to use, copy, modify, merge, publish,
9 * distribute, sub license, and/or sell copies of the Software, and to
10 * permit persons to whom the Software is furnished to do so, subject to
11 * the following conditions:
12 *
13 * The above copyright notice and this permission notice (including the
14 * next paragraph) shall be included in all copies or substantial portions
15 * of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
19 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
20 * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
21 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
22 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
23 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
24 *
25 **************************************************************************/
26
27#ifndef BEZIER_H
28#define BEZIER_H
29
30struct polygon;
31struct matrix;
32
33struct bezier {
34    float x1, y1;
35    float x2, y2;
36    float x3, y3;
37    float x4, y4;
38};
39
40
41#define BEZIER_DEFAULT_ERROR 0.01
42
43/* kappa as being l of a circle with r = 1, we can emulate any
44 * circle of radius r by using the formula
45 * l = r . kappa
46 * More at:
47 * http://www.whizkidtech.redprince.net/bezier/circle/ */
48#define KAPPA 0.5522847498
49
50void bezier_init(struct bezier *bez,
51                 float x1, float y1,
52                 float x2, float y2,
53                 float x3, float y3,
54                 float x4, float y4);
55
56struct polygon *bezier_to_polygon(struct bezier *bez);
57void bezier_add_to_polygon(const struct bezier *bez,
58                           struct polygon *poly);
59float bezier_length(struct bezier *bez, float error);
60void bezier_transform(struct bezier *bez,
61                      struct matrix *mat);
62
63int bezier_translate_by_normal(struct bezier *b,
64                               struct bezier *curves,
65                               int max_curves,
66                               float normal_len,
67                               float threshold);
68void bezier_bounds(const struct bezier *bez,
69                   float *bounds/*x/y/width/height*/);
70void bezier_exact_bounds(const struct bezier *bez,
71                         float *bounds/*x/y/width/height*/);
72
73void bezier_start_tangent(const struct bezier *bez,
74                          float *tangent);
75
76void bezier_point_at_length(struct bezier *bez, float length,
77                            float *point, float *normal);
78void bezier_point_at_t(struct bezier *bez, float t,
79                       float *point, float *normal);
80
81#endif
82