st_atom_viewport.c revision 6393cda6766b707ef01e925d378239a66d143ae0 
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 "context.h"
30#include "colormac.h"
31#include "st_context.h"
32#include "softpipe/sp_context.h"
33#include "st_atom.h"
34
35
36
37
38
39/**
40 * Update the viewport transformation matrix.  Depends on:
41 *  - viewport pos/size
42 *  - depthrange
43 *  - window pos/size or FBO size
44 */
45static void update_viewport( struct st_context *st )
46{
47   GLcontext *ctx = st->ctx;
48   const GLframebuffer *DrawBuffer = ctx->DrawBuffer;
49   GLfloat yScale = 1.0;
50   GLfloat yBias = 0.0;
51
52   /* _NEW_BUFFERS
53    */
54   if (DrawBuffer) {
55
56#if 0
57      if (DrawBuffer->Name) {
58	 /* User created FBO */
59	 struct st_renderbuffer *irb
60	    = st_renderbuffer(DrawBuffer->_ColorDrawBuffers[0][0]);
61	 if (irb && !irb->RenderToTexture) {
62	    /* y=0=top */
63	    yScale = -1.0;
64	    yBias = irb->Base.Height;
65	 }
66	 else {
67	    /* y=0=bottom */
68	    yScale = 1.0;
69	    yBias = 0.0;
70	 }
71      }
72      else
73      {
74	 /* window buffer, y=0=top */
75	 yScale = -1.0;
76	 yBias = DrawBuffer->Height;
77      }
78#endif
79   }
80
81   {
82      /* _NEW_VIEWPORT
83       */
84      GLfloat x = ctx->Viewport.X;
85      GLfloat y = ctx->Viewport.Y;
86      GLfloat z = ctx->Viewport.Near;
87      GLfloat half_width = ctx->Viewport.Width / 2.0;
88      GLfloat half_height = ctx->Viewport.Height / 2.0;
89      GLfloat half_depth = (ctx->Viewport.Far - ctx->Viewport.Near) / 2.0;
90
91      struct softpipe_viewport vp;
92
93      vp.scale[0] = half_width;
94      vp.scale[1] = half_height * yScale;
95      vp.scale[2] = half_depth;
96      vp.scale[3] = 1.0;
97
98      vp.translate[0] = (half_width + x);
99      vp.translate[1] = (half_height + y) * yScale + yBias;
100      vp.translate[2] = (half_depth + z);
101      vp.translate[3] = 0.0;
102
103      if (memcmp(&vp, &st->state.viewport, sizeof(vp)) != 0) {
104	 st->state.viewport = vp;
105	 st->softpipe->set_viewport(st->softpipe, &vp);
106      }
107   }
108}
109
110
111const struct st_tracked_state st_update_viewport = {
112   .dirty = {
113      .mesa = _NEW_BUFFERS | _NEW_VIEWPORT,
114      .st = 0,
115   },
116   .update = update_viewport
117};
118