1/*
2 * Permission is hereby granted, free of charge, to any person obtaining a
3 * copy of this software and associated documentation files (the "Software"),
4 * to deal in the Software without restriction, including without limitation
5 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
6 * and/or sell copies of the Software, and to permit persons to whom the
7 * Software is furnished to do so, subject to the following conditions:
8 *
9 * The above copyright notice and this permission notice (including the next
10 * paragraph) shall be included in all copies or substantial portions of the
11 * Software.
12 *
13 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
14 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
15 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
16 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
17 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
18 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
19 * IN THE SOFTWARE.
20 */
21
22#include "pipe/p_defines.h"
23#include "util/u_debug.h"
24#include "util/u_split_draw.h"
25
26bool
27u_split_draw(const struct pipe_draw_info *info, uint32_t max_verts,
28             uint32_t *count, uint32_t *step)
29{
30   if (*count <= max_verts) {
31      *step = *count;
32      return false;
33   }
34
35   switch (info->mode) {
36      case PIPE_PRIM_POINTS:
37         *count = *step = max_verts;
38         break;
39      case PIPE_PRIM_LINES:
40         *count = *step = max_verts - (max_verts % 2);
41         break;
42      case PIPE_PRIM_LINE_STRIP:
43         *count = max_verts;
44         *step = max_verts - 1;
45         break;
46      case PIPE_PRIM_LINE_LOOP:
47         *count = max_verts;
48         *step = max_verts - 1;
49         debug_warn_once("unhandled line loop "
50                         "looping behavior with "
51                         ">max vert count\n");
52         break;
53      case PIPE_PRIM_TRIANGLES:
54         *count = *step = max_verts - (max_verts % 3);
55         break;
56      case PIPE_PRIM_TRIANGLE_STRIP:
57         *count = max_verts;
58         *step = max_verts - 2;
59         break;
60      default:
61         debug_warn_once("unhandled primitive "
62                         "max vert count, truncating\n");
63         *count = *step = max_verts;
64   }
65
66   return true;
67}
68