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 "mtypes.h"
35#include "viewport.h"
36
37
38/**
39 * Set the viewport.
40 * \sa Called via glViewport() or display list execution.
41 *
42 * Flushes the vertices and calls _mesa_set_viewport() with the given
43 * parameters.
44 */
45void GLAPIENTRY
46_mesa_Viewport(GLint x, GLint y, GLsizei width, GLsizei height)
47{
48   GET_CURRENT_CONTEXT(ctx);
49   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
50   _mesa_set_viewport(ctx, x, y, width, height);
51}
52
53
54/**
55 * Set new viewport parameters and update derived state (the _WindowMap
56 * matrix).  Usually called from _mesa_Viewport().
57 *
58 * \param ctx GL context.
59 * \param x, y coordinates of the lower left corner of the viewport rectangle.
60 * \param width width of the viewport rectangle.
61 * \param height height of the viewport rectangle.
62 */
63void
64_mesa_set_viewport(struct gl_context *ctx, GLint x, GLint y,
65                    GLsizei width, GLsizei height)
66{
67   if (MESA_VERBOSE & VERBOSE_API)
68      _mesa_debug(ctx, "glViewport %d %d %d %d\n", x, y, width, height);
69
70   if (width < 0 || height < 0) {
71      _mesa_error(ctx,  GL_INVALID_VALUE,
72                   "glViewport(%d, %d, %d, %d)", x, y, width, height);
73      return;
74   }
75
76   /* clamp width and height to the implementation dependent range */
77   width  = MIN2(width, (GLsizei) ctx->Const.MaxViewportWidth);
78   height = MIN2(height, (GLsizei) ctx->Const.MaxViewportHeight);
79
80   ctx->Viewport.X = x;
81   ctx->Viewport.Width = width;
82   ctx->Viewport.Y = y;
83   ctx->Viewport.Height = height;
84   ctx->NewState |= _NEW_VIEWPORT;
85
86#if 1
87   /* XXX remove this someday.  Currently the DRI drivers rely on
88    * the WindowMap matrix being up to date in the driver's Viewport
89    * and DepthRange functions.
90    */
91   _math_matrix_viewport(&ctx->Viewport._WindowMap,
92                         ctx->Viewport.X, ctx->Viewport.Y,
93                         ctx->Viewport.Width, ctx->Viewport.Height,
94                         ctx->Viewport.Near, ctx->Viewport.Far,
95                         ctx->DrawBuffer->_DepthMaxF);
96#endif
97
98   if (ctx->Driver.Viewport) {
99      /* Many drivers will use this call to check for window size changes
100       * and reallocate the z/stencil/accum/etc buffers if needed.
101       */
102      ctx->Driver.Viewport(ctx, x, y, width, height);
103   }
104}
105
106
107/**
108 * Called by glDepthRange
109 *
110 * \param nearval  specifies the Z buffer value which should correspond to
111 *                 the near clip plane
112 * \param farval  specifies the Z buffer value which should correspond to
113 *                the far clip plane
114 */
115void GLAPIENTRY
116_mesa_DepthRange(GLclampd nearval, GLclampd farval)
117{
118   GET_CURRENT_CONTEXT(ctx);
119   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
120
121   if (MESA_VERBOSE&VERBOSE_API)
122      _mesa_debug(ctx, "glDepthRange %f %f\n", nearval, farval);
123
124   if (ctx->Viewport.Near == nearval &&
125       ctx->Viewport.Far == farval)
126      return;
127
128   ctx->Viewport.Near = (GLfloat) CLAMP(nearval, 0.0, 1.0);
129   ctx->Viewport.Far = (GLfloat) CLAMP(farval, 0.0, 1.0);
130   ctx->NewState |= _NEW_VIEWPORT;
131
132#if 1
133   /* XXX remove this someday.  Currently the DRI drivers rely on
134    * the WindowMap matrix being up to date in the driver's Viewport
135    * and DepthRange functions.
136    */
137   _math_matrix_viewport(&ctx->Viewport._WindowMap,
138                         ctx->Viewport.X, ctx->Viewport.Y,
139                         ctx->Viewport.Width, ctx->Viewport.Height,
140                         ctx->Viewport.Near, ctx->Viewport.Far,
141                         ctx->DrawBuffer->_DepthMaxF);
142#endif
143
144   if (ctx->Driver.DepthRange) {
145      ctx->Driver.DepthRange(ctx, nearval, farval);
146   }
147}
148
149void GLAPIENTRY
150_mesa_DepthRangef(GLclampf nearval, GLclampf farval)
151{
152   _mesa_DepthRange(nearval, farval);
153}
154
155/**
156 * Initialize the context viewport attribute group.
157 * \param ctx  the GL context.
158 */
159void _mesa_init_viewport(struct gl_context *ctx)
160{
161   GLfloat depthMax = 65535.0F; /* sorf of arbitrary */
162
163   /* Viewport group */
164   ctx->Viewport.X = 0;
165   ctx->Viewport.Y = 0;
166   ctx->Viewport.Width = 0;
167   ctx->Viewport.Height = 0;
168   ctx->Viewport.Near = 0.0;
169   ctx->Viewport.Far = 1.0;
170   _math_matrix_ctr(&ctx->Viewport._WindowMap);
171
172   _math_matrix_viewport(&ctx->Viewport._WindowMap, 0, 0, 0, 0,
173                         0.0F, 1.0F, depthMax);
174}
175
176
177/**
178 * Free the context viewport attribute group data.
179 * \param ctx  the GL context.
180 */
181void _mesa_free_viewport_data(struct gl_context *ctx)
182{
183   _math_matrix_dtr(&ctx->Viewport._WindowMap);
184}
185
186