1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
|
/*
* Copyright © 2002 University of Southern California
*
* Permission to use, copy, modify, distribute, and sell this software
* and its documentation for any purpose is hereby granted without
* fee, provided that the above copyright notice appear in all copies
* and that both that copyright notice and this permission notice
* appear in supporting documentation, and that the name of the
* University of Southern California not be used in advertising or
* publicity pertaining to distribution of the software without
* specific, written prior permission. The University of Southern
* California makes no representations about the suitability of this
* software for any purpose. It is provided "as is" without express
* or implied warranty.
*
* THE UNIVERSITY OF SOUTHERN CALIFORNIA DISCLAIMS ALL WARRANTIES WITH
* REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL THE UNIVERSITY OF
* SOUTHERN CALIFORNIA BE LIABLE FOR ANY SPECIAL, INDIRECT OR
* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
* OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
* NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* Author: Carl D. Worth <cworth@isi.edu>
*/
#include <stdlib.h>
#include "cairoint.h"
#define CAIRO_POLYGON_GROWTH_INC 10
/* private functions */
static cairo_status_t
_cairo_polygon_grow_by (cairo_polygon_t *polygon, int additional);
void
_cairo_polygon_init (cairo_polygon_t *polygon)
{
polygon->num_edges = 0;
polygon->edges_size = 0;
polygon->edges = NULL;
polygon->has_current_point = 0;
}
void
_cairo_polygon_fini (cairo_polygon_t *polygon)
{
if (polygon->edges_size) {
free (polygon->edges);
polygon->edges = NULL;
polygon->edges_size = 0;
polygon->num_edges = 0;
}
polygon->has_current_point = 0;
}
static cairo_status_t
_cairo_polygon_grow_by (cairo_polygon_t *polygon, int additional)
{
cairo_edge_t *new_edges;
int old_size = polygon->edges_size;
int new_size = polygon->num_edges + additional;
if (new_size <= polygon->edges_size) {
return CAIRO_STATUS_SUCCESS;
}
polygon->edges_size = new_size;
new_edges = realloc (polygon->edges, polygon->edges_size * sizeof (cairo_edge_t));
if (new_edges == NULL) {
polygon->edges_size = old_size;
return CAIRO_STATUS_NO_MEMORY;
}
polygon->edges = new_edges;
return CAIRO_STATUS_SUCCESS;
}
cairo_status_t
_cairo_polygon_add_edge (cairo_polygon_t *polygon, cairo_point_t *p1, cairo_point_t *p2)
{
cairo_status_t status;
cairo_edge_t *edge;
/* drop horizontal edges */
if (p1->y == p2->y) {
goto DONE;
}
if (polygon->num_edges >= polygon->edges_size) {
status = _cairo_polygon_grow_by (polygon, CAIRO_POLYGON_GROWTH_INC);
if (status) {
return status;
}
}
edge = &polygon->edges[polygon->num_edges];
if (p1->y < p2->y) {
edge->edge.p1 = *p1;
edge->edge.p2 = *p2;
edge->clockWise = 1;
} else {
edge->edge.p1 = *p2;
edge->edge.p2 = *p1;
edge->clockWise = 0;
}
polygon->num_edges++;
DONE:
_cairo_polygon_move_to (polygon, p2);
return CAIRO_STATUS_SUCCESS;
}
cairo_status_t
_cairo_polygon_move_to (cairo_polygon_t *polygon, cairo_point_t *point)
{
if (! polygon->has_current_point)
polygon->first_point = *point;
polygon->current_point = *point;
polygon->has_current_point = 1;
return CAIRO_STATUS_SUCCESS;
}
cairo_status_t
_cairo_polygon_line_to (cairo_polygon_t *polygon, cairo_point_t *point)
{
cairo_status_t status = CAIRO_STATUS_SUCCESS;
if (polygon->has_current_point) {
status = _cairo_polygon_add_edge (polygon, &polygon->current_point, point);
} else {
_cairo_polygon_move_to (polygon, point);
}
return status;
}
cairo_status_t
_cairo_polygon_close (cairo_polygon_t *polygon)
{
cairo_status_t status;
if (polygon->has_current_point) {
status = _cairo_polygon_add_edge (polygon,
&polygon->current_point,
&polygon->first_point);
if (status)
return status;
polygon->has_current_point = 0;
}
return CAIRO_STATUS_SUCCESS;
}
|
