depth.c revision c1f859d4 
1/*
2 * Mesa 3-D graphics library
3 * Version:  7.1
4 *
5 * Copyright (C) 1999-2007  Brian Paul   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#include "glheader.h"
27#include "imports.h"
28#include "context.h"
29#include "depth.h"
30#include "enums.h"
31#include "macros.h"
32#include "mtypes.h"
33
34
35/**********************************************************************/
36/*****                          API Functions                     *****/
37/**********************************************************************/
38
39
40
41void GLAPIENTRY
42_mesa_ClearDepth( GLclampd depth )
43{
44   GET_CURRENT_CONTEXT(ctx);
45   ASSERT_OUTSIDE_BEGIN_END(ctx);
46
47   depth = CLAMP( depth, 0.0, 1.0 );
48
49   if (ctx->Depth.Clear == depth)
50      return;
51
52   FLUSH_VERTICES(ctx, _NEW_DEPTH);
53   ctx->Depth.Clear = depth;
54   if (ctx->Driver.ClearDepth)
55      (*ctx->Driver.ClearDepth)( ctx, ctx->Depth.Clear );
56}
57
58
59
60void GLAPIENTRY
61_mesa_DepthFunc( GLenum func )
62{
63   GET_CURRENT_CONTEXT(ctx);
64   ASSERT_OUTSIDE_BEGIN_END(ctx);
65
66   if (MESA_VERBOSE & (VERBOSE_API|VERBOSE_TEXTURE))
67      _mesa_debug(ctx, "glDepthFunc %s\n", _mesa_lookup_enum_by_nr(func));
68
69   switch (func) {
70   case GL_LESS:    /* (default) pass if incoming z < stored z */
71   case GL_GEQUAL:
72   case GL_LEQUAL:
73   case GL_GREATER:
74   case GL_NOTEQUAL:
75   case GL_EQUAL:
76   case GL_ALWAYS:
77   case GL_NEVER:
78      break;
79   default:
80      _mesa_error( ctx, GL_INVALID_ENUM, "glDepth.Func" );
81      return;
82   }
83
84   if (ctx->Depth.Func == func)
85      return;
86
87   FLUSH_VERTICES(ctx, _NEW_DEPTH);
88   ctx->Depth.Func = func;
89
90   if (ctx->Driver.DepthFunc)
91      ctx->Driver.DepthFunc( ctx, func );
92}
93
94
95
96void GLAPIENTRY
97_mesa_DepthMask( GLboolean flag )
98{
99   GET_CURRENT_CONTEXT(ctx);
100   ASSERT_OUTSIDE_BEGIN_END(ctx);
101
102   if (MESA_VERBOSE & (VERBOSE_API|VERBOSE_TEXTURE))
103      _mesa_debug(ctx, "glDepthMask %d\n", flag);
104
105   /*
106    * GL_TRUE indicates depth buffer writing is enabled (default)
107    * GL_FALSE indicates depth buffer writing is disabled
108    */
109   if (ctx->Depth.Mask == flag)
110      return;
111
112   FLUSH_VERTICES(ctx, _NEW_DEPTH);
113   ctx->Depth.Mask = flag;
114
115   if (ctx->Driver.DepthMask)
116      ctx->Driver.DepthMask( ctx, flag );
117}
118
119
120
121/**
122 * Specified by the GL_EXT_depth_bounds_test extension.
123 */
124void GLAPIENTRY
125_mesa_DepthBoundsEXT( GLclampd zmin, GLclampd zmax )
126{
127   GET_CURRENT_CONTEXT(ctx);
128   ASSERT_OUTSIDE_BEGIN_END(ctx);
129
130   if (zmin > zmax) {
131      _mesa_error(ctx, GL_INVALID_VALUE, "glDepthBoundsEXT(zmin > zmax)");
132      return;
133   }
134
135   zmin = CLAMP(zmin, 0.0, 1.0);
136   zmax = CLAMP(zmax, 0.0, 1.0);
137
138   if (ctx->Depth.BoundsMin == zmin && ctx->Depth.BoundsMax == zmax)
139      return;
140
141   FLUSH_VERTICES(ctx, _NEW_DEPTH);
142   ctx->Depth.BoundsMin = (GLfloat) zmin;
143   ctx->Depth.BoundsMax = (GLfloat) zmax;
144}
145
146
147/**********************************************************************/
148/*****                      Initialization                        *****/
149/**********************************************************************/
150
151
152/**
153 * Initialize the depth buffer attribute group in the given context.
154 */
155void
156_mesa_init_depth(GLcontext *ctx)
157{
158   ctx->Depth.Test = GL_FALSE;
159   ctx->Depth.Clear = 1.0;
160   ctx->Depth.Func = GL_LESS;
161   ctx->Depth.Mask = GL_TRUE;
162}
163