src/gallium/auxiliary/draw/draw_pt_util.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2007 VMware, Inc.
   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 VMWARE 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 <keithw@vmware.com>
  31   */
  32
  33 #include "draw/draw_context.h"
  34 #include "draw/draw_private.h"
  35 #include "draw/draw_pt.h"
  36 #include "util/u_debug.h"
  37
  38 void draw_pt_split_prim(unsigned prim, unsigned *first, unsigned *incr)
  39 {
  40    switch (prim) {
  41    case PIPE_PRIM_POINTS:
  42       *first = 1;
  43       *incr = 1;
  44       break;
  45    case PIPE_PRIM_LINES:
  46       *first = 2;
  47       *incr = 2;
  48       break;
  49    case PIPE_PRIM_LINE_STRIP:
  50    case PIPE_PRIM_LINE_LOOP:
  51       *first = 2;
  52       *incr = 1;
  53       break;
  54    case PIPE_PRIM_LINES_ADJACENCY:
  55       *first = 4;
  56       *incr = 4;
  57       break;
  58    case PIPE_PRIM_LINE_STRIP_ADJACENCY:
  59       *first = 4;
  60       *incr = 1;
  61       break;
  62    case PIPE_PRIM_TRIANGLES:
  63       *first = 3;
  64       *incr = 3;
  65       break;
  66    case PIPE_PRIM_TRIANGLES_ADJACENCY:
  67       *first = 6;
  68       *incr = 6;
  69       break;
  70    case PIPE_PRIM_TRIANGLE_STRIP:
  71    case PIPE_PRIM_TRIANGLE_FAN:
  72    case PIPE_PRIM_POLYGON:
  73       *first = 3;
  74       *incr = 1;
  75       break;
  76    case PIPE_PRIM_TRIANGLE_STRIP_ADJACENCY:
  77       *first = 6;
  78       *incr = 2;
  79       break;
  80    case PIPE_PRIM_QUADS:
  81       *first = 4;
  82       *incr = 4;
  83       break;
  84    case PIPE_PRIM_QUAD_STRIP:
  85       *first = 4;
  86       *incr = 2;
  87       break;
  88    default:
  89       assert(0);
  90       *first = 0;
  91       *incr = 1;                /* set to one so that count % incr works */
  92       break;
  93    }
  94 }
  95
  96 unsigned draw_pt_trim_count(unsigned count, unsigned first, unsigned incr)
  97 {
  98    if (count < first)
  99       return 0;
 100    return count - (count - first) % incr;
 101 }