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 */
45 void GLAPIENTRY
_mesa_Viewport(GLint x,GLint y,GLsizei width,GLsizei height)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 */
63 void
_mesa_set_viewport(struct gl_context * ctx,GLint x,GLint y,GLsizei width,GLsizei height)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 */
115 void GLAPIENTRY
_mesa_DepthRange(GLclampd nearval,GLclampd farval)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
149 void GLAPIENTRY
_mesa_DepthRangef(GLclampf nearval,GLclampf farval)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 */
_mesa_init_viewport(struct gl_context * ctx)159 void _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 */
_mesa_free_viewport_data(struct gl_context * ctx)181 void _mesa_free_viewport_data(struct gl_context *ctx)
182 {
183 _math_matrix_dtr(&ctx->Viewport._WindowMap);
184 }
185
186