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  * \brief polygon stipple state
30  *
31  * Authors:
32  *   Brian Paul
33  */
34
35
36#include <assert.h>
37
38#include "st_context.h"
39#include "st_atom.h"
40#include "pipe/p_context.h"
41#include "pipe/p_defines.h"
42
43
44/**
45 * OpenGL's polygon stipple is indexed with window coordinates in which
46 * the origin (0,0) is the lower-left corner of the window.
47 * With Gallium, the origin is the upper-left corner of the window.
48 * To convert GL's polygon stipple to what gallium expects we need to
49 * invert the pattern vertically and rotate the stipple rows according
50 * to the window height.
51 */
52static void
53invert_stipple(GLuint dest[32], const GLuint src[32], GLuint winHeight)
54{
55   GLuint i;
56
57   for (i = 0; i < 32; i++) {
58      dest[i] = src[(winHeight - 1 - i) & 0x1f];
59   }
60}
61
62
63
64static void
65update_stipple( struct st_context *st )
66{
67   const struct gl_context *ctx = st->ctx;
68   const GLuint sz = sizeof(st->state.poly_stipple);
69   assert(sz == sizeof(ctx->PolygonStipple));
70
71   if (memcmp(st->state.poly_stipple, ctx->PolygonStipple, sz)) {
72      /* state has changed */
73      struct pipe_poly_stipple newStipple;
74
75      memcpy(st->state.poly_stipple, ctx->PolygonStipple, sz);
76
77      invert_stipple(newStipple.stipple, ctx->PolygonStipple,
78                     ctx->DrawBuffer->Height);
79
80      st->pipe->set_polygon_stipple(st->pipe, &newStipple);
81   }
82}
83
84
85/** Update the stipple when the pattern or window height changes */
86const struct st_tracked_state st_update_polygon_stipple = {
87   "st_update_polygon_stipple",				/* name */
88   {							/* dirty */
89      (_NEW_POLYGONSTIPPLE |
90       _NEW_BUFFERS),					/* mesa */
91      0,						/* st */
92   },
93   update_stipple					/* update */
94};
95