reactos/lib/mesa32/src/main/clip.c

   1
   2 /*
   3  * Mesa 3-D graphics library
   4  * Version:  5.1
   5  *
   6  * Copyright (C) 1999-2001  Brian Paul   All Rights Reserved.
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a
   9  * copy of this software and associated documentation files (the "Software"),
  10  * to deal in the Software without restriction, including without limitation
  11  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  12  * and/or sell copies of the Software, and to permit persons to whom the
  13  * Software is furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice shall be included
  16  * in all copies or substantial portions of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  21  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  22  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  23  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  24  */
  25
  26
  27 #include "glheader.h"
  28 #include "clip.h"
  29 #include "context.h"
  30 #include "macros.h"
  31 #include "mtypes.h"
  32
  33 #include "math/m_xform.h"
  34 #include "math/m_matrix.h"
  35
  36
  37
  38 /**********************************************************************/
  39 /*                     Get/Set User clip-planes.                      */
  40 /**********************************************************************/
  41
  42
  43
  44 void GLAPIENTRY
  45 _mesa_ClipPlane( GLenum plane, const GLdouble *eq )
  46 {
  47    GET_CURRENT_CONTEXT(ctx);
  48    GLint p;
  49    GLfloat equation[4];
  50    ASSERT_OUTSIDE_BEGIN_END(ctx);
  51
  52    p = (GLint) plane - (GLint) GL_CLIP_PLANE0;
  53    if (p < 0 || p >= (GLint) ctx->Const.MaxClipPlanes) {
  54       _mesa_error( ctx, GL_INVALID_ENUM, "glClipPlane" );
  55       return;
  56    }
  57
  58    equation[0] = (GLfloat) eq[0];
  59    equation[1] = (GLfloat) eq[1];
  60    equation[2] = (GLfloat) eq[2];
  61    equation[3] = (GLfloat) eq[3];
  62
  63    /*
  64     * The equation is transformed by the transpose of the inverse of the
  65     * current modelview matrix and stored in the resulting eye coordinates.
  66     *
  67     * KW: Eqn is then transformed to the current clip space, where user
  68     * clipping now takes place.  The clip-space equations are recalculated
  69     * whenever the projection matrix changes.
  70     */
  71    if (ctx->ModelviewMatrixStack.Top->flags & MAT_DIRTY)
  72       _math_matrix_analyse( ctx->ModelviewMatrixStack.Top );
  73
  74    _mesa_transform_vector( equation, equation,
  75                            ctx->ModelviewMatrixStack.Top->inv );
  76
  77    if (TEST_EQ_4V(ctx->Transform.EyeUserPlane[p], equation))
  78       return;
  79
  80    FLUSH_VERTICES(ctx, _NEW_TRANSFORM);
  81    COPY_4FV(ctx->Transform.EyeUserPlane[p], equation);
  82
  83    /* Update derived state.  This state also depends on the projection
  84     * matrix, and is recalculated on changes to the projection matrix by
  85     * code in _mesa_update_state().
  86     */
  87    if (ctx->Transform.ClipPlanesEnabled & (1 << p)) {
  88       if (ctx->ProjectionMatrixStack.Top->flags & MAT_DIRTY)
  89          _math_matrix_analyse( ctx->ProjectionMatrixStack.Top );
  90
  91       _mesa_transform_vector( ctx->Transform._ClipUserPlane[p],
  92                            ctx->Transform.EyeUserPlane[p],
  93                            ctx->ProjectionMatrixStack.Top->inv );
  94    }
  95
  96    if (ctx->Driver.ClipPlane)
  97       ctx->Driver.ClipPlane( ctx, plane, equation );
  98 }
  99
 100
 101 void GLAPIENTRY
 102 _mesa_GetClipPlane( GLenum plane, GLdouble *equation )
 103 {
 104    GET_CURRENT_CONTEXT(ctx);
 105    GLint p;
 106    ASSERT_OUTSIDE_BEGIN_END(ctx);
 107
 108    p = (GLint) (plane - GL_CLIP_PLANE0);
 109    if (p < 0 || p >= (GLint) ctx->Const.MaxClipPlanes) {
 110       _mesa_error( ctx, GL_INVALID_ENUM, "glGetClipPlane" );
 111       return;
 112    }
 113
 114    equation[0] = (GLdouble) ctx->Transform.EyeUserPlane[p][0];
 115    equation[1] = (GLdouble) ctx->Transform.EyeUserPlane[p][1];
 116    equation[2] = (GLdouble) ctx->Transform.EyeUserPlane[p][2];
 117    equation[3] = (GLdouble) ctx->Transform.EyeUserPlane[p][3];
 118 }
 119
 120 void GLAPIENTRY
 121 _mesa_CullParameterfvEXT (GLenum cap, GLfloat *v)
 122 {
 123    GET_CURRENT_CONTEXT(ctx);
 124    ASSERT_OUTSIDE_BEGIN_END(ctx);
 125
 126    switch (cap) {
 127    case GL_CULL_VERTEX_EYE_POSITION_EXT:
 128       FLUSH_VERTICES(ctx, _NEW_TRANSFORM);
 129       COPY_4FV(ctx->Transform.CullEyePos, v);
 130
 131       _mesa_transform_vector( ctx->Transform.CullObjPos,
 132                               ctx->Transform.CullEyePos,
 133                               ctx->ModelviewMatrixStack.Top->inv );
 134       break;
 135
 136    case GL_CULL_VERTEX_OBJECT_POSITION_EXT:
 137       FLUSH_VERTICES(ctx, _NEW_TRANSFORM);
 138       COPY_4FV(ctx->Transform.CullObjPos, v);
 139
 140       _mesa_transform_vector( ctx->Transform.CullEyePos,
 141                               ctx->Transform.CullObjPos,
 142                               ctx->ModelviewMatrixStack.Top->m );
 143      break;
 144    default:
 145       _mesa_error( ctx, GL_INVALID_ENUM, "glCullParameterfvEXT" );
 146    }
 147 }
 148
 149 void GLAPIENTRY
 150 _mesa_CullParameterdvEXT (GLenum cap, GLdouble *v)
 151 {
 152    GLfloat f[4];
 153
 154    f[0] = (GLfloat)v[0];
 155    f[1] = (GLfloat)v[1];
 156    f[2] = (GLfloat)v[2];
 157    f[3] = (GLfloat)v[3];
 158
 159    _mesa_CullParameterfvEXT(cap, f);
 160 }
 161