src/mesa/main/depth.c

   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
  41 void 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
  60 void 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
  96 void 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  */
 124 void 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  */
 155 void
 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 }