src/gallium/auxiliary/draw/draw_pt_util.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   * Authors:
  30   *   Keith Whitwell <keith@tungstengraphics.com>
  31   */
  32
  33 #include "draw/draw_context.h"
  34 #include "draw/draw_private.h"
  35 #include "draw/draw_pt.h"
  36
  37 void draw_pt_split_prim(unsigned prim, unsigned *first, unsigned *incr)
  38 {
  39    switch (prim) {
  40    case PIPE_PRIM_POINTS:
  41       *first = 1;
  42       *incr = 1;
  43       break;
  44    case PIPE_PRIM_LINES:
  45       *first = 2;
  46       *incr = 2;
  47       break;
  48    case PIPE_PRIM_LINE_STRIP:
  49    case PIPE_PRIM_LINE_LOOP:
  50       *first = 2;
  51       *incr = 1;
  52       break;
  53    case PIPE_PRIM_TRIANGLES:
  54       *first = 3;
  55       *incr = 3;
  56       break;
  57    case PIPE_PRIM_TRIANGLE_STRIP:
  58    case PIPE_PRIM_TRIANGLE_FAN:
  59    case PIPE_PRIM_POLYGON:
  60       *first = 3;
  61       *incr = 1;
  62       break;
  63    case PIPE_PRIM_QUADS:
  64       *first = 4;
  65       *incr = 4;
  66       break;
  67    case PIPE_PRIM_QUAD_STRIP:
  68       *first = 4;
  69       *incr = 2;
  70       break;
  71    default:
  72       assert(0);
  73       *first = 0;
  74       *incr = 1;                /* set to one so that count % incr works */
  75       break;
  76    }
  77 }