st_atom_viewport.c revision f9995b30756140724f41daf963fa06167912be7f 
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 */
41static void
42update_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      yScale = -1;
51      yBias = (GLfloat)ctx->DrawBuffer->Height;
52   }
53   else {
54      yScale = 1.0;
55      yBias = 0.0;
56   }
57
58   /* _NEW_VIEWPORT
59    */
60   {
61      GLfloat x = (GLfloat)ctx->Viewport.X;
62      GLfloat y = (GLfloat)ctx->Viewport.Y;
63      GLfloat z = ctx->Viewport.Near;
64      GLfloat half_width = (GLfloat)ctx->Viewport.Width * 0.5f;
65      GLfloat half_height = (GLfloat)ctx->Viewport.Height * 0.5f;
66      GLfloat half_depth = (GLfloat)(ctx->Viewport.Far - ctx->Viewport.Near) * 0.5f;
67
68      st->state.viewport.scale[0] = half_width;
69      st->state.viewport.scale[1] = half_height * yScale;
70      st->state.viewport.scale[2] = half_depth;
71      st->state.viewport.scale[3] = 1.0;
72
73      st->state.viewport.translate[0] = half_width + x;
74      st->state.viewport.translate[1] = (half_height + y) * yScale + yBias;
75      st->state.viewport.translate[2] = half_depth + z;
76      st->state.viewport.translate[3] = 0.0;
77
78      cso_set_viewport(st->cso_context, &st->state.viewport);
79   }
80}
81
82
83const struct st_tracked_state st_update_viewport = {
84   "st_update_viewport",				/* name */
85   {							/* dirty */
86      _NEW_BUFFERS | _NEW_VIEWPORT,			/* mesa */
87      0,						/* st */
88   },
89   update_viewport					/* update */
90};
91