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#include "util/u_debug.h"
37
38void 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
96unsigned 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}
102