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 #include "main/context.h"
30 #include "st_context.h"
31 #include "st_atom.h"
32 #include "pipe/p_context.h"
33 #include "cso_cache/cso_context.h"
34
35 /**
36 * Update the viewport transformation matrix. Depends on:
37 * - viewport pos/size
38 * - depthrange
39 * - window pos/size or FBO size
40 */
41 static void
update_viewport(struct st_context * st)42 update_viewport( struct st_context *st )
43 {
44 struct gl_context *ctx = st->ctx;
45 GLfloat yScale, yBias;
46
47 /* _NEW_BUFFERS
48 */
49 if (st_fb_orientation(ctx->DrawBuffer) == Y_0_TOP) {
50 /* Drawing to a window. The corresponding gallium surface uses
51 * Y=0=TOP but OpenGL is Y=0=BOTTOM. So we need to invert the viewport.
52 */
53 yScale = -1;
54 yBias = (GLfloat)ctx->DrawBuffer->Height;
55 }
56 else {
57 /* Drawing to an FBO where Y=0=BOTTOM, like OpenGL - don't invert */
58 yScale = 1.0;
59 yBias = 0.0;
60 }
61
62 /* _NEW_VIEWPORT
63 */
64 {
65 GLfloat x = (GLfloat)ctx->Viewport.X;
66 GLfloat y = (GLfloat)ctx->Viewport.Y;
67 GLfloat z = ctx->Viewport.Near;
68 GLfloat half_width = (GLfloat)ctx->Viewport.Width * 0.5f;
69 GLfloat half_height = (GLfloat)ctx->Viewport.Height * 0.5f;
70 GLfloat half_depth = (GLfloat)(ctx->Viewport.Far - ctx->Viewport.Near) * 0.5f;
71
72 st->state.viewport.scale[0] = half_width;
73 st->state.viewport.scale[1] = half_height * yScale;
74 st->state.viewport.scale[2] = half_depth;
75 st->state.viewport.scale[3] = 1.0;
76
77 st->state.viewport.translate[0] = half_width + x;
78 st->state.viewport.translate[1] = (half_height + y) * yScale + yBias;
79 st->state.viewport.translate[2] = half_depth + z;
80 st->state.viewport.translate[3] = 0.0;
81
82 cso_set_viewport(st->cso_context, &st->state.viewport);
83 }
84 }
85
86
87 const struct st_tracked_state st_update_viewport = {
88 "st_update_viewport", /* name */
89 { /* dirty */
90 _NEW_BUFFERS | _NEW_VIEWPORT, /* mesa */
91 0, /* st */
92 },
93 update_viewport /* update */
94 };
95