1 /*
2 * Mesa 3-D graphics library
3 *
4 * Copyright (C) 1999-2006 Brian Paul All Rights Reserved.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 * and/or sell copies of the Software, and to permit persons to whom the
11 * Software is furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included
14 * in all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
17 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
20 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
21 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
22 * OTHER DEALINGS IN THE SOFTWARE.
23 *
24 * Authors:
25 * Keith Whitwell <keithw@vmware.com>
26 */
27
28
29 #include "main/glheader.h"
30 #include "main/macros.h"
31
32 #include "main/mtypes.h"
33
34 #include "math/m_xform.h"
35
36 #include "t_context.h"
37 #include "t_pipeline.h"
38
39
40 struct normal_stage_data {
41 normal_func NormalTransform;
42 GLvector4f normal;
43 };
44
45 #define NORMAL_STAGE_DATA(stage) ((struct normal_stage_data *)stage->privatePtr)
46
47
48 static GLboolean
run_normal_stage(struct gl_context * ctx,struct tnl_pipeline_stage * stage)49 run_normal_stage(struct gl_context *ctx, struct tnl_pipeline_stage *stage)
50 {
51 struct normal_stage_data *store = NORMAL_STAGE_DATA(stage);
52 struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
53 const GLfloat *lengths;
54
55 if (!store->NormalTransform)
56 return GL_TRUE;
57
58 /* We can only use the display list's saved normal lengths if we've
59 * got a transformation matrix with uniform scaling.
60 */
61 if (_math_matrix_is_general_scale(ctx->ModelviewMatrixStack.Top))
62 lengths = NULL;
63 else
64 lengths = VB->NormalLengthPtr;
65
66 store->NormalTransform( ctx->ModelviewMatrixStack.Top,
67 ctx->_ModelViewInvScale,
68 VB->AttribPtr[_TNL_ATTRIB_NORMAL], /* input normals */
69 lengths,
70 &store->normal ); /* resulting normals */
71
72 if (VB->AttribPtr[_TNL_ATTRIB_NORMAL]->count > 1) {
73 store->normal.stride = 4 * sizeof(GLfloat);
74 }
75 else {
76 store->normal.stride = 0;
77 }
78
79 VB->AttribPtr[_TNL_ATTRIB_NORMAL] = &store->normal;
80
81 VB->NormalLengthPtr = NULL; /* no longer valid */
82 return GL_TRUE;
83 }
84
85
86 /**
87 * Examine current GL state and set the store->NormalTransform pointer
88 * to point to the appropriate normal transformation routine.
89 */
90 static void
validate_normal_stage(struct gl_context * ctx,struct tnl_pipeline_stage * stage)91 validate_normal_stage(struct gl_context *ctx, struct tnl_pipeline_stage *stage)
92 {
93 struct normal_stage_data *store = NORMAL_STAGE_DATA(stage);
94
95 if (ctx->VertexProgram._Current ||
96 (!ctx->Light.Enabled &&
97 !(ctx->Texture._GenFlags & TEXGEN_NEED_NORMALS))) {
98 store->NormalTransform = NULL;
99 return;
100 }
101
102 if (ctx->_NeedEyeCoords) {
103 /* Eye coordinates are needed, for whatever reasons.
104 * Do lighting in eye coordinates, as the GL spec says.
105 */
106 GLuint transform = NORM_TRANSFORM_NO_ROT;
107
108 if (_math_matrix_has_rotation(ctx->ModelviewMatrixStack.Top)) {
109 /* need to do full (3x3) matrix transform */
110 transform = NORM_TRANSFORM;
111 }
112
113 if (ctx->Transform.Normalize) {
114 store->NormalTransform = _mesa_normal_tab[transform | NORM_NORMALIZE];
115 }
116 else if (ctx->Transform.RescaleNormals &&
117 ctx->_ModelViewInvScale != 1.0F) {
118 store->NormalTransform = _mesa_normal_tab[transform | NORM_RESCALE];
119 }
120 else {
121 store->NormalTransform = _mesa_normal_tab[transform];
122 }
123 }
124 else {
125 /* We don't need eye coordinates.
126 * Do lighting in object coordinates. Thus, we don't need to fully
127 * transform normal vectors (just leave them in object coordinates)
128 * but we still need to do normalization/rescaling if enabled.
129 */
130 if (ctx->Transform.Normalize) {
131 store->NormalTransform = _mesa_normal_tab[NORM_NORMALIZE];
132 }
133 else if (!ctx->Transform.RescaleNormals &&
134 ctx->_ModelViewInvScale != 1.0F) {
135 store->NormalTransform = _mesa_normal_tab[NORM_RESCALE];
136 }
137 else {
138 store->NormalTransform = NULL;
139 }
140 }
141 }
142
143
144 /**
145 * Allocate stage's private data (storage for transformed normals).
146 */
147 static GLboolean
alloc_normal_data(struct gl_context * ctx,struct tnl_pipeline_stage * stage)148 alloc_normal_data(struct gl_context *ctx, struct tnl_pipeline_stage *stage)
149 {
150 TNLcontext *tnl = TNL_CONTEXT(ctx);
151 struct normal_stage_data *store;
152
153 stage->privatePtr = malloc(sizeof(*store));
154 store = NORMAL_STAGE_DATA(stage);
155 if (!store)
156 return GL_FALSE;
157
158 _mesa_vector4f_alloc( &store->normal, 0, tnl->vb.Size, 32 );
159 return GL_TRUE;
160 }
161
162
163 /**
164 * Free stage's private data.
165 */
166 static void
free_normal_data(struct tnl_pipeline_stage * stage)167 free_normal_data(struct tnl_pipeline_stage *stage)
168 {
169 struct normal_stage_data *store = NORMAL_STAGE_DATA(stage);
170 if (store) {
171 _mesa_vector4f_free( &store->normal );
172 free( store );
173 stage->privatePtr = NULL;
174 }
175 }
176
177
178 const struct tnl_pipeline_stage _tnl_normal_transform_stage =
179 {
180 "normal transform", /* name */
181 NULL, /* privatePtr */
182 alloc_normal_data, /* create */
183 free_normal_data, /* destroy */
184 validate_normal_stage, /* validate */
185 run_normal_stage /* run */
186 };
187