src/gallium/drivers/softpipe/sp_quad_occlusion.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
   4  * All Rights Reserved.
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  11  * permit persons to whom the Software is furnished to do so, subject to
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  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
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  27
  28
  29 /**
  30  * \brief  Quad occlusion counter stage
  31  * \author  Brian Paul
  32  */
  33
  34
  35 #include "pipe/p_defines.h"
  36 #include "util/u_memory.h"
  37 #include "sp_context.h"
  38 #include "sp_headers.h"
  39 #include "sp_surface.h"
  40 #include "sp_quad.h"
  41
  42 static unsigned count_bits( unsigned val )
  43 {
  44    unsigned i;
  45
  46    for (i = 0; val ; val >>= 1)
  47       i += (val & 1);
  48
  49    return i;
  50 }
  51
  52 static void
  53 occlusion_count_quad(struct quad_stage *qs, struct quad_header *quad)
  54 {
  55    struct softpipe_context *softpipe = qs->softpipe;
  56
  57    softpipe->occlusion_count += count_bits(quad->mask);
  58
  59    qs->next->run(qs->next, quad);
  60 }
  61
  62
  63 static void occlusion_begin(struct quad_stage *qs)
  64 {
  65    qs->next->begin(qs->next);
  66 }
  67
  68
  69 static void occlusion_destroy(struct quad_stage *qs)
  70 {
  71    FREE( qs );
  72 }
  73
  74
  75 struct quad_stage *sp_quad_occlusion_stage( struct softpipe_context *softpipe )
  76 {
  77    struct quad_stage *stage = CALLOC_STRUCT(quad_stage);
  78
  79    stage->softpipe = softpipe;
  80    stage->begin = occlusion_begin;
  81    stage->run = occlusion_count_quad;
  82    stage->destroy = occlusion_destroy;
  83
  84    return stage;
  85 }