src/mesa/tnl/t_vb_normals.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.1
   4  *
   5  * Copyright (C) 1999-2004  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  * Authors:
  25  *    Keith Whitwell <keith@tungstengraphics.com>
  26  */
  27
  28
  29 #include "glheader.h"
  30 #include "colormac.h"
  31 #include "context.h"
  32 #include "macros.h"
  33 #include "imports.h"
  34 #include "mtypes.h"
  35
  36 #include "math/m_xform.h"
  37
  38 #include "t_context.h"
  39 #include "t_pipeline.h"
  40
  41
  42
  43 struct normal_stage_data {
  44    normal_func NormalTransform;
  45    GLvector4f normal;
  46 };
  47
  48 #define NORMAL_STAGE_DATA(stage) ((struct normal_stage_data *)stage->privatePtr)
  49
  50
  51
  52
  53 static GLboolean run_normal_stage( GLcontext *ctx,
  54                                    struct tnl_pipeline_stage *stage )
  55 {
  56    struct normal_stage_data *store = NORMAL_STAGE_DATA(stage);
  57    struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
  58    const GLfloat *lengths;
  59
  60    if (!store->NormalTransform)
  61       return GL_TRUE;
  62
  63    /* We can only use the display list's saved normal lengths if we've
  64     * got a transformation matrix with uniform scaling.
  65     */
  66    if (ctx->ModelviewMatrixStack.Top->flags & MAT_FLAG_GENERAL_SCALE)
  67       lengths = NULL;
  68    else
  69       lengths = VB->NormalLengthPtr;
  70
  71    store->NormalTransform( ctx->ModelviewMatrixStack.Top,
  72                            ctx->_ModelViewInvScale,
  73                            VB->NormalPtr,  /* input normals */
  74                            lengths,
  75                            &store->normal ); /* resulting normals */
  76
  77    if (VB->NormalPtr->count > 1) {
  78       store->normal.stride = 16;
  79    }
  80    else {
  81       store->normal.stride = 0;
  82    }
  83
  84    VB->NormalPtr = &store->normal;
  85    VB->AttribPtr[_TNL_ATTRIB_NORMAL] = VB->NormalPtr;
  86
  87    VB->NormalLengthPtr = NULL;  /* no longer valid */
  88    return GL_TRUE;
  89 }
  90
  91
  92 static void validate_normal_stage( GLcontext *ctx,
  93                                             struct tnl_pipeline_stage *stage )
  94 {
  95    struct normal_stage_data *store = NORMAL_STAGE_DATA(stage);
  96
  97    if (ctx->VertexProgram._Enabled ||
  98        (!ctx->Light.Enabled &&
  99         !(ctx->Texture._GenFlags & TEXGEN_NEED_NORMALS))) {
 100       store->NormalTransform = NULL;
 101       return;
 102    }
 103
 104
 105    if (ctx->_NeedEyeCoords) {
 106       GLuint transform = NORM_TRANSFORM_NO_ROT;
 107
 108       if (ctx->ModelviewMatrixStack.Top->flags & (MAT_FLAG_GENERAL |
 109                                   MAT_FLAG_ROTATION |
 110                                   MAT_FLAG_GENERAL_3D |
 111                                   MAT_FLAG_PERSPECTIVE))
 112          transform = NORM_TRANSFORM;
 113
 114
 115       if (ctx->Transform.Normalize) {
 116          store->NormalTransform = _mesa_normal_tab[transform | NORM_NORMALIZE];
 117       }
 118       else if (ctx->Transform.RescaleNormals &&
 119                ctx->_ModelViewInvScale != 1.0) {
 120          store->NormalTransform = _mesa_normal_tab[transform | NORM_RESCALE];
 121       }
 122       else {
 123          store->NormalTransform = _mesa_normal_tab[transform];
 124       }
 125    }
 126    else {
 127       if (ctx->Transform.Normalize) {
 128          store->NormalTransform = _mesa_normal_tab[NORM_NORMALIZE];
 129       }
 130       else if (!ctx->Transform.RescaleNormals &&
 131                ctx->_ModelViewInvScale != 1.0) {
 132          store->NormalTransform = _mesa_normal_tab[NORM_RESCALE];
 133       }
 134       else {
 135          store->NormalTransform = NULL;
 136       }
 137    }
 138 }
 139
 140
 141
 142 static GLboolean alloc_normal_data( GLcontext *ctx,
 143                                  struct tnl_pipeline_stage *stage )
 144 {
 145    TNLcontext *tnl = TNL_CONTEXT(ctx);
 146    struct normal_stage_data *store;
 147    stage->privatePtr = MALLOC(sizeof(*store));
 148    store = NORMAL_STAGE_DATA(stage);
 149    if (!store)
 150       return GL_FALSE;
 151
 152    _mesa_vector4f_alloc( &store->normal, 0, tnl->vb.Size, 32 );
 153    return GL_TRUE;
 154 }
 155
 156
 157
 158 static void free_normal_data( struct tnl_pipeline_stage *stage )
 159 {
 160    struct normal_stage_data *store = NORMAL_STAGE_DATA(stage);
 161    if (store) {
 162       _mesa_vector4f_free( &store->normal );
 163       FREE( store );
 164       stage->privatePtr = NULL;
 165    }
 166 }
 167
 168
 169 const struct tnl_pipeline_stage _tnl_normal_transform_stage =
 170 {
 171    "normal transform",          /* name */
 172    NULL,                        /* private data */
 173    alloc_normal_data,
 174    free_normal_data,            /* destructor */
 175    validate_normal_stage,       /* check */
 176    run_normal_stage
 177 };