1 /*
2 * Copyright (C) 2020 Collabora, Ltd.
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21 * SOFTWARE.
22 *
23 */
24
25 #include "util/ralloc.h"
26 #include "pan_partial_update.h"
27
28 static struct pan_rect
pan_make_rect(unsigned minx,unsigned miny,unsigned maxx,unsigned maxy)29 pan_make_rect(unsigned minx, unsigned miny, unsigned maxx, unsigned maxy)
30 {
31 struct pan_rect r = {
32 .minx = minx,
33 .miny = miny,
34 .maxx = maxx,
35 .maxy = maxy
36 };
37
38 return r;
39 }
40
41 static struct pan_rect
pan_from_pipe(const struct pipe_box * p)42 pan_from_pipe(const struct pipe_box *p)
43 {
44 return pan_make_rect(p->x, p->y, p->x + p->width, p->y + p->height);
45 }
46
47 /* Helper to clip a rect inside another box */
48
49 static struct pan_rect
pan_clip_rect(const struct pan_rect * r,const struct pan_rect * clip)50 pan_clip_rect(
51 const struct pan_rect *r,
52 const struct pan_rect *clip)
53 {
54 unsigned minx = MAX2(r->minx, clip->minx);
55 unsigned miny = MAX2(r->miny, clip->miny);
56 unsigned maxx = MAX2(MIN2(r->maxx, clip->maxx), minx);
57 unsigned maxy = MAX2(MIN2(r->maxy, clip->maxy), miny);
58
59 return pan_make_rect(minx, miny, maxx, maxy);
60 }
61
62 /* Subtract d from r, yielding four (possibly degenerate) rectangles for each
63 * bounding region */
64
65 static void
pan_subtract_from_rect(struct pan_rect * out,const struct pan_rect * r,const struct pan_rect * d)66 pan_subtract_from_rect(
67 struct pan_rect *out,
68 const struct pan_rect *r,
69 const struct pan_rect *d)
70 {
71 struct pan_rect dc = pan_clip_rect(r, d);
72
73 out[0] = pan_make_rect(r->minx, r->miny, dc.minx, r->maxy);
74 out[1] = pan_make_rect(dc.minx, r->miny, dc.maxx, dc.miny);
75 out[2] = pan_make_rect(dc.maxx, r->miny, r->maxx, r->maxy);
76 out[3] = pan_make_rect(dc.minx, dc.maxy, dc.maxx, r->maxy);
77 }
78
79 /* Subtract d from the set of rects R, returning the number of
80 * (non-degenerate) rectangles returned.
81 *
82 * out must be at least sizeof(struct pan_rect) * R_len * 4 bytes
83 *
84 * Trivially satisfies: return value < (R_len * 4) */
85
86 static unsigned
pan_subtract_from_rects(struct pan_rect * out,const struct pan_rect * R,unsigned R_len,const struct pan_rect * d)87 pan_subtract_from_rects(
88 struct pan_rect *out,
89 const struct pan_rect *R,
90 unsigned R_len,
91 const struct pan_rect *d)
92 {
93 unsigned count = 0;
94 struct pan_rect temp[4];
95
96 for (unsigned r = 0; r < R_len; ++r) {
97 pan_subtract_from_rect(temp, &R[r], d);
98
99 /* Copy the rectangles with nonzero area */
100 for (unsigned i = 0; i < 4; ++i) {
101 if (temp[i].maxx <= temp[i].minx) continue;
102 if (temp[i].maxy <= temp[i].miny) continue;
103
104 out[count++] = temp[i];
105 }
106 }
107
108 return count;
109 }
110
111 struct pan_rect *
pan_subtract_damage(void * memctx,unsigned initial_w,unsigned initial_h,unsigned nrects,const struct pipe_box * rects,unsigned * out_len)112 pan_subtract_damage(
113 void *memctx,
114 unsigned initial_w, unsigned initial_h,
115 unsigned nrects,
116 const struct pipe_box *rects,
117 unsigned *out_len)
118 {
119 struct pan_rect *R = ralloc(memctx, struct pan_rect);
120 *R = pan_make_rect(0, 0, initial_w, initial_h);
121 unsigned R_len = 1;
122
123 for (unsigned d = 0; d < nrects; ++d) {
124 const struct pan_rect D = pan_from_pipe(&rects[d]);
125 struct pan_rect *out = rzalloc_array(memctx, struct pan_rect,
126 R_len * 4);
127
128 R_len = pan_subtract_from_rects(out, R, R_len, &D);
129 ralloc_free(R);
130 R = out;
131 }
132
133 *out_len = R_len;
134 return R;
135 }
136