src/gallium/drivers/softpipe/sp_quad_coverage.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  21  * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
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  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28
  29 /**
  30  * \brief  Apply AA coverage to quad alpha valus
  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_quad.h"
  40
  41
  42 /**
  43  * Multiply quad's alpha values by the fragment coverage.
  44  */
  45 static void
  46 coverage_quad(struct quad_stage *qs, struct quad_header *quad)
  47 {
  48    struct softpipe_context *softpipe = qs->softpipe;
  49
  50    if ((softpipe->rasterizer->poly_smooth && quad->input.prim == PRIM_TRI) ||
  51        (softpipe->rasterizer->line_smooth && quad->input.prim == PRIM_LINE) ||
  52        (softpipe->rasterizer->point_smooth && quad->input.prim == PRIM_POINT)) {
  53       uint cbuf;
  54
  55       /* loop over colorbuffer outputs */
  56       for (cbuf = 0; cbuf < softpipe->framebuffer.nr_cbufs; cbuf++) {
  57          float (*quadColor)[4] = quad->output.color[cbuf];
  58          unsigned j;
  59          for (j = 0; j < QUAD_SIZE; j++) {
  60             assert(quad->input.coverage[j] >= 0.0);
  61             assert(quad->input.coverage[j] <= 1.0);
  62          quadColor[3][j] *= quad->input.coverage[j];
  63          }
  64       }
  65    }
  66
  67    qs->next->run(qs->next, quad);
  68 }
  69
  70
  71 static void coverage_begin(struct quad_stage *qs)
  72 {
  73    qs->next->begin(qs->next);
  74 }
  75
  76
  77 static void coverage_destroy(struct quad_stage *qs)
  78 {
  79    FREE( qs );
  80 }
  81
  82
  83 struct quad_stage *sp_quad_coverage_stage( struct softpipe_context *softpipe )
  84 {
  85    struct quad_stage *stage = CALLOC_STRUCT(quad_stage);
  86
  87    stage->softpipe = softpipe;
  88    stage->begin = coverage_begin;
  89    stage->run = coverage_quad;
  90    stage->destroy = coverage_destroy;
  91
  92    return stage;
  93 }