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/macros.h"
32 #include "main/imports.h"
33 #include "main/mtypes.h"
34
35 #include "math/m_xform.h"
36
37 #include "t_context.h"
38 #include "t_pipeline.h"
39
40
41 struct normal_stage_data {
42 normal_func NormalTransform;
43 GLvector4f normal;
44 };
45
46 #define NORMAL_STAGE_DATA(stage) ((struct normal_stage_data *)stage->privatePtr)
47
48
49 static GLboolean
run_normal_stage(struct gl_context * ctx,struct tnl_pipeline_stage * stage)50 run_normal_stage(struct gl_context *ctx, struct tnl_pipeline_stage *stage)
51 {
52 struct normal_stage_data *store = NORMAL_STAGE_DATA(stage);
53 struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
54 const GLfloat *lengths;
55
56 if (!store->NormalTransform)
57 return GL_TRUE;
58
59 /* We can only use the display list's saved normal lengths if we've
60 * got a transformation matrix with uniform scaling.
61 */
62 if (_math_matrix_is_general_scale(ctx->ModelviewMatrixStack.Top))
63 lengths = NULL;
64 else
65 lengths = VB->NormalLengthPtr;
66
67 store->NormalTransform( ctx->ModelviewMatrixStack.Top,
68 ctx->_ModelViewInvScale,
69 VB->AttribPtr[_TNL_ATTRIB_NORMAL], /* input normals */
70 lengths,
71 &store->normal ); /* resulting normals */
72
73 if (VB->AttribPtr[_TNL_ATTRIB_NORMAL]->count > 1) {
74 store->normal.stride = 4 * sizeof(GLfloat);
75 }
76 else {
77 store->normal.stride = 0;
78 }
79
80 VB->AttribPtr[_TNL_ATTRIB_NORMAL] = &store->normal;
81
82 VB->NormalLengthPtr = NULL; /* no longer valid */
83 return GL_TRUE;
84 }
85
86
87 /**
88 * Examine current GL state and set the store->NormalTransform pointer
89 * to point to the appropriate normal transformation routine.
90 */
91 static void
validate_normal_stage(struct gl_context * ctx,struct tnl_pipeline_stage * stage)92 validate_normal_stage(struct gl_context *ctx, struct tnl_pipeline_stage *stage)
93 {
94 struct normal_stage_data *store = NORMAL_STAGE_DATA(stage);
95
96 if (ctx->VertexProgram._Current ||
97 (!ctx->Light.Enabled &&
98 !(ctx->Texture._GenFlags & TEXGEN_NEED_NORMALS))) {
99 store->NormalTransform = NULL;
100 return;
101 }
102
103 if (ctx->_NeedEyeCoords) {
104 /* Eye coordinates are needed, for whatever reasons.
105 * Do lighting in eye coordinates, as the GL spec says.
106 */
107 GLuint transform = NORM_TRANSFORM_NO_ROT;
108
109 if (_math_matrix_has_rotation(ctx->ModelviewMatrixStack.Top)) {
110 /* need to do full (3x3) matrix transform */
111 transform = NORM_TRANSFORM;
112 }
113
114 if (ctx->Transform.Normalize) {
115 store->NormalTransform = _mesa_normal_tab[transform | NORM_NORMALIZE];
116 }
117 else if (ctx->Transform.RescaleNormals &&
118 ctx->_ModelViewInvScale != 1.0) {
119 store->NormalTransform = _mesa_normal_tab[transform | NORM_RESCALE];
120 }
121 else {
122 store->NormalTransform = _mesa_normal_tab[transform];
123 }
124 }
125 else {
126 /* We don't need eye coordinates.
127 * Do lighting in object coordinates. Thus, we don't need to fully
128 * transform normal vectors (just leave them in object coordinates)
129 * but we still need to do normalization/rescaling if enabled.
130 */
131 if (ctx->Transform.Normalize) {
132 store->NormalTransform = _mesa_normal_tab[NORM_NORMALIZE];
133 }
134 else if (!ctx->Transform.RescaleNormals &&
135 ctx->_ModelViewInvScale != 1.0) {
136 store->NormalTransform = _mesa_normal_tab[NORM_RESCALE];
137 }
138 else {
139 store->NormalTransform = NULL;
140 }
141 }
142 }
143
144
145 /**
146 * Allocate stage's private data (storage for transformed normals).
147 */
148 static GLboolean
alloc_normal_data(struct gl_context * ctx,struct tnl_pipeline_stage * stage)149 alloc_normal_data(struct gl_context *ctx, struct tnl_pipeline_stage *stage)
150 {
151 TNLcontext *tnl = TNL_CONTEXT(ctx);
152 struct normal_stage_data *store;
153
154 stage->privatePtr = malloc(sizeof(*store));
155 store = NORMAL_STAGE_DATA(stage);
156 if (!store)
157 return GL_FALSE;
158
159 _mesa_vector4f_alloc( &store->normal, 0, tnl->vb.Size, 32 );
160 return GL_TRUE;
161 }
162
163
164 /**
165 * Free stage's private data.
166 */
167 static void
free_normal_data(struct tnl_pipeline_stage * stage)168 free_normal_data(struct tnl_pipeline_stage *stage)
169 {
170 struct normal_stage_data *store = NORMAL_STAGE_DATA(stage);
171 if (store) {
172 _mesa_vector4f_free( &store->normal );
173 free( store );
174 stage->privatePtr = NULL;
175 }
176 }
177
178
179 const struct tnl_pipeline_stage _tnl_normal_transform_stage =
180 {
181 "normal transform", /* name */
182 NULL, /* privatePtr */
183 alloc_normal_data, /* create */
184 free_normal_data, /* destroy */
185 validate_normal_stage, /* validate */
186 run_normal_stage /* run */
187 };
188