Merge branch 'mesa_7_7_branch'
[mesa.git] / src / mesa / tnl / t_vb_normals.c
1 /*
2 * Mesa 3-D graphics library
3 * Version: 6.5
4 *
5 * Copyright (C) 1999-2006 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 "main/glheader.h"
30 #include "main/colormac.h"
31 #include "main/context.h"
32 #include "main/macros.h"
33 #include "main/imports.h"
34 #include "main/mtypes.h"
35
36 #include "math/m_xform.h"
37
38 #include "t_context.h"
39 #include "t_pipeline.h"
40
41
42 struct normal_stage_data {
43 normal_func NormalTransform;
44 GLvector4f normal;
45 };
46
47 #define NORMAL_STAGE_DATA(stage) ((struct normal_stage_data *)stage->privatePtr)
48
49
50 static GLboolean
51 run_normal_stage(GLcontext *ctx, struct tnl_pipeline_stage *stage)
52 {
53 struct normal_stage_data *store = NORMAL_STAGE_DATA(stage);
54 struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
55 const GLfloat *lengths;
56
57 if (!store->NormalTransform)
58 return GL_TRUE;
59
60 /* We can only use the display list's saved normal lengths if we've
61 * got a transformation matrix with uniform scaling.
62 */
63 if (_math_matrix_is_general_scale(ctx->ModelviewMatrixStack.Top))
64 lengths = NULL;
65 else
66 lengths = VB->NormalLengthPtr;
67
68 store->NormalTransform( ctx->ModelviewMatrixStack.Top,
69 ctx->_ModelViewInvScale,
70 VB->AttribPtr[_TNL_ATTRIB_NORMAL], /* input normals */
71 lengths,
72 &store->normal ); /* resulting normals */
73
74 if (VB->AttribPtr[_TNL_ATTRIB_NORMAL]->count > 1) {
75 store->normal.stride = 4 * sizeof(GLfloat);
76 }
77 else {
78 store->normal.stride = 0;
79 }
80
81 VB->AttribPtr[_TNL_ATTRIB_NORMAL] = &store->normal;
82
83 VB->NormalLengthPtr = NULL; /* no longer valid */
84 return GL_TRUE;
85 }
86
87
88 /**
89 * Examine current GL state and set the store->NormalTransform pointer
90 * to point to the appropriate normal transformation routine.
91 */
92 static void
93 validate_normal_stage(GLcontext *ctx, struct tnl_pipeline_stage *stage)
94 {
95 struct normal_stage_data *store = NORMAL_STAGE_DATA(stage);
96
97 if (ctx->VertexProgram._Current ||
98 (!ctx->Light.Enabled &&
99 !(ctx->Texture._GenFlags & TEXGEN_NEED_NORMALS))) {
100 store->NormalTransform = NULL;
101 return;
102 }
103
104 if (ctx->_NeedEyeCoords) {
105 /* Eye coordinates are needed, for whatever reasons.
106 * Do lighting in eye coordinates, as the GL spec says.
107 */
108 GLuint transform = NORM_TRANSFORM_NO_ROT;
109
110 if (_math_matrix_has_rotation(ctx->ModelviewMatrixStack.Top)) {
111 /* need to do full (3x3) matrix transform */
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 /* We don't need eye coordinates.
128 * Do lighting in object coordinates. Thus, we don't need to fully
129 * transform normal vectors (just leave them in object coordinates)
130 * but we still need to do normalization/rescaling if enabled.
131 */
132 if (ctx->Transform.Normalize) {
133 store->NormalTransform = _mesa_normal_tab[NORM_NORMALIZE];
134 }
135 else if (!ctx->Transform.RescaleNormals &&
136 ctx->_ModelViewInvScale != 1.0) {
137 store->NormalTransform = _mesa_normal_tab[NORM_RESCALE];
138 }
139 else {
140 store->NormalTransform = NULL;
141 }
142 }
143 }
144
145
146 /**
147 * Allocate stage's private data (storage for transformed normals).
148 */
149 static GLboolean
150 alloc_normal_data(GLcontext *ctx, struct tnl_pipeline_stage *stage)
151 {
152 TNLcontext *tnl = TNL_CONTEXT(ctx);
153 struct normal_stage_data *store;
154
155 stage->privatePtr = _mesa_malloc(sizeof(*store));
156 store = NORMAL_STAGE_DATA(stage);
157 if (!store)
158 return GL_FALSE;
159
160 _mesa_vector4f_alloc( &store->normal, 0, tnl->vb.Size, 32 );
161 return GL_TRUE;
162 }
163
164
165 /**
166 * Free stage's private data.
167 */
168 static void
169 free_normal_data(struct tnl_pipeline_stage *stage)
170 {
171 struct normal_stage_data *store = NORMAL_STAGE_DATA(stage);
172 if (store) {
173 _mesa_vector4f_free( &store->normal );
174 _mesa_free( store );
175 stage->privatePtr = NULL;
176 }
177 }
178
179
180 const struct tnl_pipeline_stage _tnl_normal_transform_stage =
181 {
182 "normal transform", /* name */
183 NULL, /* privatePtr */
184 alloc_normal_data, /* create */
185 free_normal_data, /* destroy */
186 validate_normal_stage, /* validate */
187 run_normal_stage /* run */
188 };