1
2/**
3 * quad polygon stipple stage
4 */
5
6#include "sp_context.h"
7#include "sp_quad.h"
8#include "sp_quad_pipe.h"
9#include "pipe/p_defines.h"
10#include "util/u_memory.h"
11
12
13/**
14 * Apply polygon stipple to quads produced by triangle rasterization
15 */
16static void
17stipple_quad(struct quad_stage *qs, struct quad_header *quads[], unsigned nr)
18{
19   static const uint bit31 = 1 << 31;
20   static const uint bit30 = 1 << 30;
21   unsigned pass = nr;
22
23   struct softpipe_context *softpipe = qs->softpipe;
24   unsigned q;
25
26   pass = 0;
27
28   for (q = 0; q < nr; q++)  {
29      struct quad_header *quad = quads[q];
30
31      const int col0 = quad->input.x0 % 32;
32      const int y0 = quad->input.y0;
33      const int y1 = y0 + 1;
34      const uint stipple0 = softpipe->poly_stipple.stipple[y0 % 32];
35      const uint stipple1 = softpipe->poly_stipple.stipple[y1 % 32];
36
37      /* turn off quad mask bits that fail the stipple test */
38      if ((stipple0 & (bit31 >> col0)) == 0)
39         quad->inout.mask &= ~MASK_TOP_LEFT;
40
41      if ((stipple0 & (bit30 >> col0)) == 0)
42         quad->inout.mask &= ~MASK_TOP_RIGHT;
43
44      if ((stipple1 & (bit31 >> col0)) == 0)
45         quad->inout.mask &= ~MASK_BOTTOM_LEFT;
46
47      if ((stipple1 & (bit30 >> col0)) == 0)
48         quad->inout.mask &= ~MASK_BOTTOM_RIGHT;
49
50      if (quad->inout.mask)
51         quads[pass++] = quad;
52   }
53
54   qs->next->run(qs->next, quads, pass);
55}
56
57
58static void stipple_begin(struct quad_stage *qs)
59{
60   qs->next->begin(qs->next);
61}
62
63
64static void stipple_destroy(struct quad_stage *qs)
65{
66   FREE( qs );
67}
68
69
70struct quad_stage *
71sp_quad_polygon_stipple_stage( struct softpipe_context *softpipe )
72{
73   struct quad_stage *stage = CALLOC_STRUCT(quad_stage);
74
75   stage->softpipe = softpipe;
76   stage->begin = stipple_begin;
77   stage->run = stipple_quad;
78   stage->destroy = stipple_destroy;
79
80   return stage;
81}
82