aboutsummaryrefslogtreecommitdiffstats
path: root/src/mesa/tnl/t_vb_normals.c
blob: c2aa655674cc51819070a9f2353a85da3aee9149 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
/*
 * Mesa 3-D graphics library
 * Version:  6.5
 *
 * Copyright (C) 1999-2006  Brian Paul   All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 * Authors:
 *    Keith Whitwell <keith@tungstengraphics.com>
 */


#include "main/glheader.h"
#include "main/colormac.h"
#include "main/macros.h"
#include "main/imports.h"
#include "main/mtypes.h"

#include "math/m_xform.h"

#include "t_context.h"
#include "t_pipeline.h"


struct normal_stage_data {
   normal_func NormalTransform;
   GLvector4f normal;
};

#define NORMAL_STAGE_DATA(stage) ((struct normal_stage_data *)stage->privatePtr)


static GLboolean
run_normal_stage(GLcontext *ctx, struct tnl_pipeline_stage *stage)
{
   struct normal_stage_data *store = NORMAL_STAGE_DATA(stage);
   struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
   const GLfloat *lengths;

   if (!store->NormalTransform)
      return GL_TRUE;

   /* We can only use the display list's saved normal lengths if we've
    * got a transformation matrix with uniform scaling.
    */
   if (_math_matrix_is_general_scale(ctx->ModelviewMatrixStack.Top))
      lengths = NULL;
   else
      lengths = VB->NormalLengthPtr;

   store->NormalTransform( ctx->ModelviewMatrixStack.Top,
			   ctx->_ModelViewInvScale,
			   VB->AttribPtr[_TNL_ATTRIB_NORMAL],  /* input normals */
			   lengths,
			   &store->normal ); /* resulting normals */

   if (VB->AttribPtr[_TNL_ATTRIB_NORMAL]->count > 1) {
      store->normal.stride = 4 * sizeof(GLfloat);
   }
   else {
      store->normal.stride = 0;
   }

   VB->AttribPtr[_TNL_ATTRIB_NORMAL] = &store->normal;

   VB->NormalLengthPtr = NULL;	/* no longer valid */
   return GL_TRUE;
}


/**
 * Examine current GL state and set the store->NormalTransform pointer
 * to point to the appropriate normal transformation routine.
 */
static void
validate_normal_stage(GLcontext *ctx, struct tnl_pipeline_stage *stage)
{
   struct normal_stage_data *store = NORMAL_STAGE_DATA(stage);

   if (ctx->VertexProgram._Current ||
       (!ctx->Light.Enabled &&
	!(ctx->Texture._GenFlags & TEXGEN_NEED_NORMALS))) {
      store->NormalTransform = NULL;
      return;
   }

   if (ctx->_NeedEyeCoords) {
      /* Eye coordinates are needed, for whatever reasons.
       * Do lighting in eye coordinates, as the GL spec says.
       */
      GLuint transform = NORM_TRANSFORM_NO_ROT;

      if (_math_matrix_has_rotation(ctx->ModelviewMatrixStack.Top)) {
         /* need to do full (3x3) matrix transform */
	 transform = NORM_TRANSFORM;
      }

      if (ctx->Transform.Normalize) {
	 store->NormalTransform = _mesa_normal_tab[transform | NORM_NORMALIZE];
      }
      else if (ctx->Transform.RescaleNormals &&
               ctx->_ModelViewInvScale != 1.0) {
	 store->NormalTransform = _mesa_normal_tab[transform | NORM_RESCALE];
      }
      else {
	 store->NormalTransform = _mesa_normal_tab[transform];
      }
   }
   else {
      /* We don't need eye coordinates.
       * Do lighting in object coordinates.  Thus, we don't need to fully
       * transform normal vectors (just leave them in object coordinates)
       * but we still need to do normalization/rescaling if enabled.
       */
      if (ctx->Transform.Normalize) {
	 store->NormalTransform = _mesa_normal_tab[NORM_NORMALIZE];
      }
      else if (!ctx->Transform.RescaleNormals &&
	       ctx->_ModelViewInvScale != 1.0) {
	 store->NormalTransform = _mesa_normal_tab[NORM_RESCALE];
      }
      else {
	 store->NormalTransform = NULL;
      }
   }
}


/**
 * Allocate stage's private data (storage for transformed normals).
 */
static GLboolean
alloc_normal_data(GLcontext *ctx, struct tnl_pipeline_stage *stage)
{
   TNLcontext *tnl = TNL_CONTEXT(ctx);
   struct normal_stage_data *store;

   stage->privatePtr = malloc(sizeof(*store));
   store = NORMAL_STAGE_DATA(stage);
   if (!store)
      return GL_FALSE;

   _mesa_vector4f_alloc( &store->normal, 0, tnl->vb.Size, 32 );
   return GL_TRUE;
}


/**
 * Free stage's private data.
 */
static void
free_normal_data(struct tnl_pipeline_stage *stage)
{
   struct normal_stage_data *store = NORMAL_STAGE_DATA(stage);
   if (store) {
      _mesa_vector4f_free( &store->normal );
      free( store );
      stage->privatePtr = NULL;
   }
}


const struct tnl_pipeline_stage _tnl_normal_transform_stage =
{
   "normal transform",		/* name */
   NULL,			/* privatePtr */
   alloc_normal_data,		/* create */
   free_normal_data,		/* destroy */
   validate_normal_stage,	/* validate */
   run_normal_stage             /* run */
};