src/gallium/drivers/panfrost/pan_partial_update.c

   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
  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
  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
  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
  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
  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 *
 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 }