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 */
52 static void
invert_stipple(GLuint dest[32],const GLuint src[32],GLuint winHeight)53 invert_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
64 static void
update_stipple(struct st_context * st)65 update_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 */
86 const 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