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 void GLAPIENTRY
  60 _mesa_ClearDepthf( GLclampf depth )
  61 {
  62    _mesa_ClearDepth(depth);
  63 }
  64
  65
  66 void GLAPIENTRY
  67 _mesa_DepthFunc( GLenum func )
  68 {
  69    GET_CURRENT_CONTEXT(ctx);
  70    ASSERT_OUTSIDE_BEGIN_END(ctx);
  71
  72    if (MESA_VERBOSE & VERBOSE_API)
  73       _mesa_debug(ctx, "glDepthFunc %s\n", _mesa_lookup_enum_by_nr(func));
  74
  75    switch (func) {
  76    case GL_LESS:    /* (default) pass if incoming z < stored z */
  77    case GL_GEQUAL:
  78    case GL_LEQUAL:
  79    case GL_GREATER:
  80    case GL_NOTEQUAL:
  81    case GL_EQUAL:
  82    case GL_ALWAYS:
  83    case GL_NEVER:
  84       break;
  85    default:
  86       _mesa_error( ctx, GL_INVALID_ENUM, "glDepth.Func" );
  87       return;
  88    }
  89
  90    if (ctx->Depth.Func == func)
  91       return;
  92
  93    FLUSH_VERTICES(ctx, _NEW_DEPTH);
  94    ctx->Depth.Func = func;
  95
  96    if (ctx->Driver.DepthFunc)
  97       ctx->Driver.DepthFunc( ctx, func );
  98 }
  99
 100
 101
 102 void GLAPIENTRY
 103 _mesa_DepthMask( GLboolean flag )
 104 {
 105    GET_CURRENT_CONTEXT(ctx);
 106    ASSERT_OUTSIDE_BEGIN_END(ctx);
 107
 108    if (MESA_VERBOSE & VERBOSE_API)
 109       _mesa_debug(ctx, "glDepthMask %d\n", flag);
 110
 111    /*
 112     * GL_TRUE indicates depth buffer writing is enabled (default)
 113     * GL_FALSE indicates depth buffer writing is disabled
 114     */
 115    if (ctx->Depth.Mask == flag)
 116       return;
 117
 118    FLUSH_VERTICES(ctx, _NEW_DEPTH);
 119    ctx->Depth.Mask = flag;
 120
 121    if (ctx->Driver.DepthMask)
 122       ctx->Driver.DepthMask( ctx, flag );
 123 }
 124
 125
 126
 127 /**
 128  * Specified by the GL_EXT_depth_bounds_test extension.
 129  */
 130 void GLAPIENTRY
 131 _mesa_DepthBoundsEXT( GLclampd zmin, GLclampd zmax )
 132 {
 133    GET_CURRENT_CONTEXT(ctx);
 134    ASSERT_OUTSIDE_BEGIN_END(ctx);
 135
 136    if (zmin > zmax) {
 137       _mesa_error(ctx, GL_INVALID_VALUE, "glDepthBoundsEXT(zmin > zmax)");
 138       return;
 139    }
 140
 141    zmin = CLAMP(zmin, 0.0, 1.0);
 142    zmax = CLAMP(zmax, 0.0, 1.0);
 143
 144    if (ctx->Depth.BoundsMin == zmin && ctx->Depth.BoundsMax == zmax)
 145       return;
 146
 147    FLUSH_VERTICES(ctx, _NEW_DEPTH);
 148    ctx->Depth.BoundsMin = (GLfloat) zmin;
 149    ctx->Depth.BoundsMax = (GLfloat) zmax;
 150 }
 151
 152
 153 /**********************************************************************/
 154 /*****                      Initialization                        *****/
 155 /**********************************************************************/
 156
 157
 158 /**
 159  * Initialize the depth buffer attribute group in the given context.
 160  */
 161 void
 162 _mesa_init_depth(struct gl_context *ctx)
 163 {
 164    ctx->Depth.Test = GL_FALSE;
 165    ctx->Depth.Clear = 1.0;
 166    ctx->Depth.Func = GL_LESS;
 167    ctx->Depth.Mask = GL_TRUE;
 168 }