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    if (MESA_VERBOSE & VERBOSE_API)
  48       _mesa_debug(ctx, "glClearDepth(%f)\n", depth);
  49
  50    depth = CLAMP( depth, 0.0, 1.0 );
  51
  52    if (ctx->Depth.Clear == depth)
  53       return;
  54
  55    FLUSH_VERTICES(ctx, _NEW_DEPTH);
  56    ctx->Depth.Clear = depth;
  57 }
  58
  59
  60 void GLAPIENTRY
  61 _mesa_ClearDepthf( GLclampf depth )
  62 {
  63    _mesa_ClearDepth(depth);
  64 }
  65
  66
  67 void GLAPIENTRY
  68 _mesa_DepthFunc( GLenum func )
  69 {
  70    GET_CURRENT_CONTEXT(ctx);
  71    ASSERT_OUTSIDE_BEGIN_END(ctx);
  72
  73    if (MESA_VERBOSE & VERBOSE_API)
  74       _mesa_debug(ctx, "glDepthFunc %s\n", _mesa_lookup_enum_by_nr(func));
  75
  76    switch (func) {
  77    case GL_LESS:    /* (default) pass if incoming z < stored z */
  78    case GL_GEQUAL:
  79    case GL_LEQUAL:
  80    case GL_GREATER:
  81    case GL_NOTEQUAL:
  82    case GL_EQUAL:
  83    case GL_ALWAYS:
  84    case GL_NEVER:
  85       break;
  86    default:
  87       _mesa_error( ctx, GL_INVALID_ENUM, "glDepth.Func" );
  88       return;
  89    }
  90
  91    if (ctx->Depth.Func == func)
  92       return;
  93
  94    FLUSH_VERTICES(ctx, _NEW_DEPTH);
  95    ctx->Depth.Func = func;
  96
  97    if (ctx->Driver.DepthFunc)
  98       ctx->Driver.DepthFunc( ctx, func );
  99 }
 100
 101
 102
 103 void GLAPIENTRY
 104 _mesa_DepthMask( GLboolean flag )
 105 {
 106    GET_CURRENT_CONTEXT(ctx);
 107    ASSERT_OUTSIDE_BEGIN_END(ctx);
 108
 109    if (MESA_VERBOSE & VERBOSE_API)
 110       _mesa_debug(ctx, "glDepthMask %d\n", flag);
 111
 112    /*
 113     * GL_TRUE indicates depth buffer writing is enabled (default)
 114     * GL_FALSE indicates depth buffer writing is disabled
 115     */
 116    if (ctx->Depth.Mask == flag)
 117       return;
 118
 119    FLUSH_VERTICES(ctx, _NEW_DEPTH);
 120    ctx->Depth.Mask = flag;
 121
 122    if (ctx->Driver.DepthMask)
 123       ctx->Driver.DepthMask( ctx, flag );
 124 }
 125
 126
 127
 128 /**
 129  * Specified by the GL_EXT_depth_bounds_test extension.
 130  */
 131 void GLAPIENTRY
 132 _mesa_DepthBoundsEXT( GLclampd zmin, GLclampd zmax )
 133 {
 134    GET_CURRENT_CONTEXT(ctx);
 135    ASSERT_OUTSIDE_BEGIN_END(ctx);
 136
 137    if (MESA_VERBOSE & VERBOSE_API)
 138       _mesa_debug(ctx, "glDepthBounds(%f, %f)\n", zmin, zmax);
 139
 140    if (zmin > zmax) {
 141       _mesa_error(ctx, GL_INVALID_VALUE, "glDepthBoundsEXT(zmin > zmax)");
 142       return;
 143    }
 144
 145    zmin = CLAMP(zmin, 0.0, 1.0);
 146    zmax = CLAMP(zmax, 0.0, 1.0);
 147
 148    if (ctx->Depth.BoundsMin == zmin && ctx->Depth.BoundsMax == zmax)
 149       return;
 150
 151    FLUSH_VERTICES(ctx, _NEW_DEPTH);
 152    ctx->Depth.BoundsMin = (GLfloat) zmin;
 153    ctx->Depth.BoundsMax = (GLfloat) zmax;
 154 }
 155
 156
 157 /**********************************************************************/
 158 /*****                      Initialization                        *****/
 159 /**********************************************************************/
 160
 161
 162 /**
 163  * Initialize the depth buffer attribute group in the given context.
 164  */
 165 void
 166 _mesa_init_depth(struct gl_context *ctx)
 167 {
 168    ctx->Depth.Test = GL_FALSE;
 169    ctx->Depth.Clear = 1.0;
 170    ctx->Depth.Func = GL_LESS;
 171    ctx->Depth.Mask = GL_TRUE;
 172 }