source: trunk/third/mozilla/other-licenses/libart_lgpl/art_rect_uta.c @ 22325

Revision 22325, 3.8 KB checked in by rbasch, 19 years ago (diff)
This commit was generated by cvs2svn to compensate for changes in r22324, which included commits to RCS files with non-trunk default branches.
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1/* Libart_LGPL - library of basic graphic primitives
2 * Copyright (C) 1998 Raph Levien
3 *
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Library General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
8 *
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12 * Library General Public License for more details.
13 *
14 * You should have received a copy of the GNU Library General Public
15 * License along with this library; if not, write to the
16 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17 * Boston, MA 02111-1307, USA.
18 */
19
20#include "config.h"
21#include "art_rect_uta.h"
22
23/* Functions to decompose a microtile array into a list of rectangles. */
24
25/**
26 * art_rect_list_from_uta: Decompose uta into list of rectangles.
27 * @uta: The source uta.
28 * @max_width: The maximum width of the resulting rectangles.
29 * @max_height: The maximum height of the resulting rectangles.
30 * @p_nrects: Where to store the number of returned rectangles.
31 *
32 * Allocates a new list of rectangles, sets *@p_nrects to the number
33 * in the list. This list should be freed with art_free().
34 *
35 * Each rectangle bounded in size by (@max_width, @max_height).
36 * However, these bounds must be at least the size of one tile.
37 *
38 * This routine provides a precise implementation, i.e. the rectangles
39 * cover exactly the same area as the uta. It is thus appropriate in
40 * cases where the overhead per rectangle is small compared with the
41 * cost of filling in extra pixels.
42 *
43 * Return value: An array containing the resulting rectangles.
44 **/
45ArtIRect *
46art_rect_list_from_uta (ArtUta *uta, int max_width, int max_height,
47                        int *p_nrects)
48{
49  ArtIRect *rects;
50  int n_rects, n_rects_max;
51  int x, y;
52  int width, height;
53  int ix;
54  int left_ix;
55  ArtUtaBbox *utiles;
56  ArtUtaBbox bb;
57  int x0, y0, x1, y1;
58  int *glom;
59  int glom_rect;
60
61  n_rects = 0;
62  n_rects_max = 1;
63  rects = art_new (ArtIRect, n_rects_max);
64
65  width = uta->width;
66  height = uta->height;
67  utiles = uta->utiles;
68
69  glom = art_new (int, width * height);
70  for (ix = 0; ix < width * height; ix++)
71    glom[ix] = -1;
72
73  ix = 0;
74  for (y = 0; y < height; y++)
75    for (x = 0; x < width; x++)
76      {
77        bb = utiles[ix];
78        if (bb)
79          {
80            x0 = ((uta->x0 + x) << ART_UTILE_SHIFT) + ART_UTA_BBOX_X0(bb);
81            y0 = ((uta->y0 + y) << ART_UTILE_SHIFT) + ART_UTA_BBOX_Y0(bb);
82            y1 = ((uta->y0 + y) << ART_UTILE_SHIFT) + ART_UTA_BBOX_Y1(bb);
83
84            left_ix = ix;
85            /* now try to extend to the right */
86            while (x != width - 1 &&
87                   ART_UTA_BBOX_X1(bb) == ART_UTILE_SIZE &&
88                   (((bb & 0xffffff) ^ utiles[ix + 1]) & 0xffff00ff) == 0 &&
89                   (((uta->x0 + x + 1) << ART_UTILE_SHIFT) +
90                    ART_UTA_BBOX_X1(utiles[ix + 1]) -
91                    x0) <= max_width)
92              {
93                bb = utiles[ix + 1];
94                ix++;
95                x++;
96              }
97            x1 = ((uta->x0 + x) << ART_UTILE_SHIFT) + ART_UTA_BBOX_X1(bb);
98
99
100            /* if rectangle nonempty */
101            if ((x1 ^ x0) | (y1 ^ y0))
102              {
103                /* try to glom onto an existing rectangle */
104                glom_rect = glom[left_ix];
105                if (glom_rect != -1 &&
106                    x0 == rects[glom_rect].x0 &&
107                    x1 == rects[glom_rect].x1 &&
108                    y0 == rects[glom_rect].y1 &&
109                    y1 - rects[glom_rect].y0 <= max_height)
110                  {
111                    rects[glom_rect].y1 = y1;
112                  }
113                else
114                  {
115                    if (n_rects == n_rects_max)
116                      art_expand (rects, ArtIRect, n_rects_max);
117                    rects[n_rects].x0 = x0;
118                    rects[n_rects].y0 = y0;
119                    rects[n_rects].x1 = x1;
120                    rects[n_rects].y1 = y1;
121                    glom_rect = n_rects;
122                    n_rects++;
123                  }
124                if (y != height - 1)
125                  glom[left_ix + width] = glom_rect;
126              }
127          }
128        ix++;
129      }
130
131  art_free (glom);
132  *p_nrects = n_rects;
133  return rects;
134}
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