viewport.c revision f9995b30756140724f41daf963fa06167912be7f 
1/*
2 * Mesa 3-D graphics library
3 * Version:  7.5
4 *
5 * Copyright (C) 2009  VMware, Inc.  All Rights Reserved.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a
8 * copy of this software and associated documentation files (the "Software"),
9 * to deal in the Software without restriction, including without limitation
10 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
11 * and/or sell copies of the Software, and to permit persons to whom the
12 * Software is furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included
15 * in all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
20 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
21 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
22 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
23 */
24
25
26/**
27 * \file viewport.c
28 * glViewport and glDepthRange functions.
29 */
30
31
32#include "context.h"
33#include "macros.h"
34#include "viewport.h"
35
36
37/**
38 * Set the viewport.
39 * \sa Called via glViewport() or display list execution.
40 *
41 * Flushes the vertices and calls _mesa_set_viewport() with the given
42 * parameters.
43 */
44void GLAPIENTRY
45_mesa_Viewport(GLint x, GLint y, GLsizei width, GLsizei height)
46{
47   GET_CURRENT_CONTEXT(ctx);
48   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
49   _mesa_set_viewport(ctx, x, y, width, height);
50}
51
52
53/**
54 * Set new viewport parameters and update derived state (the _WindowMap
55 * matrix).  Usually called from _mesa_Viewport().
56 *
57 * \param ctx GL context.
58 * \param x, y coordinates of the lower left corner of the viewport rectangle.
59 * \param width width of the viewport rectangle.
60 * \param height height of the viewport rectangle.
61 */
62void
63_mesa_set_viewport(struct gl_context *ctx, GLint x, GLint y,
64                    GLsizei width, GLsizei height)
65{
66   if (MESA_VERBOSE & VERBOSE_API)
67      _mesa_debug(ctx, "glViewport %d %d %d %d\n", x, y, width, height);
68
69   if (width < 0 || height < 0) {
70      _mesa_error(ctx,  GL_INVALID_VALUE,
71                   "glViewport(%d, %d, %d, %d)", x, y, width, height);
72      return;
73   }
74
75   /* clamp width and height to the implementation dependent range */
76   width  = MIN2(width, (GLsizei) ctx->Const.MaxViewportWidth);
77   height = MIN2(height, (GLsizei) ctx->Const.MaxViewportHeight);
78
79   ctx->Viewport.X = x;
80   ctx->Viewport.Width = width;
81   ctx->Viewport.Y = y;
82   ctx->Viewport.Height = height;
83   ctx->NewState |= _NEW_VIEWPORT;
84
85#if 1
86   /* XXX remove this someday.  Currently the DRI drivers rely on
87    * the WindowMap matrix being up to date in the driver's Viewport
88    * and DepthRange functions.
89    */
90   _math_matrix_viewport(&ctx->Viewport._WindowMap,
91                         ctx->Viewport.X, ctx->Viewport.Y,
92                         ctx->Viewport.Width, ctx->Viewport.Height,
93                         ctx->Viewport.Near, ctx->Viewport.Far,
94                         ctx->DrawBuffer->_DepthMaxF);
95#endif
96
97   if (ctx->Driver.Viewport) {
98      /* Many drivers will use this call to check for window size changes
99       * and reallocate the z/stencil/accum/etc buffers if needed.
100       */
101      ctx->Driver.Viewport(ctx, x, y, width, height);
102   }
103}
104
105
106/**
107 * Called by glDepthRange
108 *
109 * \param nearval  specifies the Z buffer value which should correspond to
110 *                 the near clip plane
111 * \param farval  specifies the Z buffer value which should correspond to
112 *                the far clip plane
113 */
114void GLAPIENTRY
115_mesa_DepthRange(GLclampd nearval, GLclampd farval)
116{
117   GET_CURRENT_CONTEXT(ctx);
118   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
119
120   if (MESA_VERBOSE&VERBOSE_API)
121      _mesa_debug(ctx, "glDepthRange %f %f\n", nearval, farval);
122
123   if (ctx->Viewport.Near == nearval &&
124       ctx->Viewport.Far == farval)
125      return;
126
127   ctx->Viewport.Near = (GLfloat) CLAMP(nearval, 0.0, 1.0);
128   ctx->Viewport.Far = (GLfloat) CLAMP(farval, 0.0, 1.0);
129   ctx->NewState |= _NEW_VIEWPORT;
130
131#if 1
132   /* XXX remove this someday.  Currently the DRI drivers rely on
133    * the WindowMap matrix being up to date in the driver's Viewport
134    * and DepthRange functions.
135    */
136   _math_matrix_viewport(&ctx->Viewport._WindowMap,
137                         ctx->Viewport.X, ctx->Viewport.Y,
138                         ctx->Viewport.Width, ctx->Viewport.Height,
139                         ctx->Viewport.Near, ctx->Viewport.Far,
140                         ctx->DrawBuffer->_DepthMaxF);
141#endif
142
143   if (ctx->Driver.DepthRange) {
144      ctx->Driver.DepthRange(ctx, nearval, farval);
145   }
146}
147
148
149
150/**
151 * Initialize the context viewport attribute group.
152 * \param ctx  the GL context.
153 */
154void _mesa_init_viewport(struct gl_context *ctx)
155{
156   GLfloat depthMax = 65535.0F; /* sorf of arbitrary */
157
158   /* Viewport group */
159   ctx->Viewport.X = 0;
160   ctx->Viewport.Y = 0;
161   ctx->Viewport.Width = 0;
162   ctx->Viewport.Height = 0;
163   ctx->Viewport.Near = 0.0;
164   ctx->Viewport.Far = 1.0;
165   _math_matrix_ctr(&ctx->Viewport._WindowMap);
166
167   _math_matrix_viewport(&ctx->Viewport._WindowMap, 0, 0, 0, 0,
168                         0.0F, 1.0F, depthMax);
169}
170
171
172/**
173 * Free the context viewport attribute group data.
174 * \param ctx  the GL context.
175 */
176void _mesa_free_viewport_data(struct gl_context *ctx)
177{
178   _math_matrix_dtr(&ctx->Viewport._WindowMap);
179}
180
181