src/mesa/pipe/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
  22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  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 "main/glheader.h"
  36 #include "main/macros.h"
  37 #include "pipe/p_defines.h"
  38 #include "sp_context.h"
  39 #include "sp_headers.h"
  40 #include "sp_quad.h"
  41
  42
  43 /**
  44  * Multiply quad's alpha values by the fragment coverage.
  45  */
  46 static void
  47 coverage_quad(struct quad_stage *qs, struct quad_header *quad)
  48 {
  49    struct softpipe_context *softpipe = qs->softpipe;
  50
  51    if ((softpipe->setup.poly_smooth && quad->prim == PRIM_TRI) ||
  52        (softpipe->setup.line_smooth && quad->prim == PRIM_LINE) ||
  53        (softpipe->setup.point_smooth && quad->prim == PRIM_POINT)) {
  54       GLuint j;
  55       for (j = 0; j < QUAD_SIZE; j++) {
  56          assert(quad->coverage[j] >= 0.0);
  57          assert(quad->coverage[j] <= 1.0);
  58          quad->outputs.color[3][j] *= quad->coverage[j];
  59       }
  60    }
  61
  62    qs->next->run(qs->next, quad);
  63 }
  64
  65
  66 struct quad_stage *sp_quad_coverage_stage( struct softpipe_context *softpipe )
  67 {
  68    struct quad_stage *stage = CALLOC_STRUCT(quad_stage);
  69
  70    stage->softpipe = softpipe;
  71    stage->run = coverage_quad;
  72
  73    return stage;
  74 }