src/gallium/drivers/softpipe/sp_quad_stipple.c

   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  */
  16 static void
  17 stipple_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
  58 static void stipple_begin(struct quad_stage *qs)
  59 {
  60    qs->next->begin(qs->next);
  61 }
  62
  63
  64 static void stipple_destroy(struct quad_stage *qs)
  65 {
  66    FREE( qs );
  67 }
  68
  69
  70 struct quad_stage *
  71 sp_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 }