1 #include <osgUtil/TangentSpaceGenerator>
2
3 #include <osg/Notify>
4 #include <osg/io_utils>
5
6 using namespace osgUtil;
7
TangentSpaceGenerator()8 TangentSpaceGenerator::TangentSpaceGenerator()
9 : osg::Referenced(),
10 T_(new osg::Vec4Array),
11 B_(new osg::Vec4Array),
12 N_(new osg::Vec4Array)
13 {
14 T_->setBinding(osg::Array::BIND_PER_VERTEX); T_->setNormalize(false);
15 B_->setBinding(osg::Array::BIND_PER_VERTEX); B_->setNormalize(false);
16 N_->setBinding(osg::Array::BIND_PER_VERTEX); N_->setNormalize(false);
17 }
18
TangentSpaceGenerator(const TangentSpaceGenerator & copy,const osg::CopyOp & copyop)19 TangentSpaceGenerator::TangentSpaceGenerator(const TangentSpaceGenerator ©, const osg::CopyOp ©op)
20 : osg::Referenced(copy),
21 T_(static_cast<osg::Vec4Array *>(copyop(copy.T_.get()))),
22 B_(static_cast<osg::Vec4Array *>(copyop(copy.B_.get()))),
23 N_(static_cast<osg::Vec4Array *>(copyop(copy.N_.get())))
24 {
25 }
26
generate(osg::Geometry * geo,int normal_map_tex_unit)27 void TangentSpaceGenerator::generate(osg::Geometry *geo, int normal_map_tex_unit)
28 {
29 const osg::Array *vx = geo->getVertexArray();
30 const osg::Array *nx = geo->getNormalArray();
31 const osg::Array *tx = geo->getTexCoordArray(normal_map_tex_unit);
32
33 if (!vx || !tx) return;
34
35
36 unsigned int vertex_count = vx->getNumElements();
37 T_->assign(vertex_count, osg::Vec4());
38 B_->assign(vertex_count, osg::Vec4());
39 N_->assign(vertex_count, osg::Vec4());
40
41 unsigned int i; // VC6 doesn't like for-scoped variables
42
43 for (unsigned int pri=0; pri<geo->getNumPrimitiveSets(); ++pri) {
44 osg::PrimitiveSet *pset = geo->getPrimitiveSet(pri);
45
46 unsigned int N = pset->getNumIndices();
47
48 switch (pset->getMode()) {
49
50 case osg::PrimitiveSet::TRIANGLES:
51 for (i=0; i<N; i+=3) {
52 compute(pset, vx, nx, tx, i, i+1, i+2);
53 }
54 break;
55
56 case osg::PrimitiveSet::QUADS:
57 for (i=0; i<N; i+=4) {
58 compute(pset, vx, nx, tx, i, i+1, i+2);
59 compute(pset, vx, nx, tx, i+2, i+3, i);
60 }
61 break;
62
63 case osg::PrimitiveSet::TRIANGLE_STRIP:
64 if (pset->getType() == osg::PrimitiveSet::DrawArrayLengthsPrimitiveType) {
65 osg::DrawArrayLengths *dal = static_cast<osg::DrawArrayLengths *>(pset);
66 unsigned int j = 0;
67 for (osg::DrawArrayLengths::const_iterator pi=dal->begin(); pi!=dal->end(); ++pi) {
68 unsigned int iN = static_cast<unsigned int>(*pi-2);
69 for (i=0; i<iN; ++i, ++j) {
70 if ((i%2) == 0) {
71 compute(pset, vx, nx, tx, j, j+1, j+2);
72 } else {
73 compute(pset, vx, nx, tx, j+1, j, j+2);
74 }
75 }
76 j += 2;
77 }
78 } else {
79 for (i=0; i<N-2; ++i) {
80 if ((i%2) == 0) {
81 compute(pset, vx, nx, tx, i, i+1, i+2);
82 } else {
83 compute(pset, vx, nx, tx, i+1, i, i+2);
84 }
85 }
86 }
87 break;
88
89 case osg::PrimitiveSet::QUAD_STRIP:
90 if (pset->getType() == osg::PrimitiveSet::DrawArrayLengthsPrimitiveType) {
91 osg::DrawArrayLengths *dal = static_cast<osg::DrawArrayLengths *>(pset);
92 unsigned int j = 0;
93 for (osg::DrawArrayLengths::const_iterator pi=dal->begin(); pi!=dal->end(); ++pi) {
94 unsigned int iN = static_cast<unsigned int>(*pi-2);
95 for (i=0; i<iN; ++i, ++j) {
96 if ((i%2) == 0) {
97 compute(pset, vx, nx, tx, j, j+2, j+1);
98 } else {
99 compute(pset, vx, nx, tx, j, j+1, j+2);
100 }
101 }
102 j += 2;
103 }
104 } else {
105 for (i=0; i<N-2; ++i) {
106 if ((i%2) == 0) {
107 compute(pset, vx, nx, tx, i, i+2, i+1);
108 } else {
109 compute(pset, vx, nx, tx, i, i+1, i+2);
110 }
111 }
112 }
113 break;
114
115 case osg::PrimitiveSet::TRIANGLE_FAN:
116 case osg::PrimitiveSet::POLYGON:
117 if (pset->getType() == osg::PrimitiveSet::DrawArrayLengthsPrimitiveType) {
118 osg::DrawArrayLengths *dal = static_cast<osg::DrawArrayLengths *>(pset);
119 unsigned int j = 0;
120 for (osg::DrawArrayLengths::const_iterator pi=dal->begin(); pi!=dal->end(); ++pi) {
121 unsigned int iN = static_cast<unsigned int>(*pi-2);
122 for (i=0; i<iN; ++i) {
123 compute(pset, vx, nx, tx, 0, j+1, j+2);
124 }
125 j += 2;
126 }
127 } else {
128 for (i=0; i<N-2; ++i) {
129 compute(pset, vx, nx, tx, 0, i+1, i+2);
130 }
131 }
132 break;
133
134 case osg::PrimitiveSet::POINTS:
135 case osg::PrimitiveSet::LINES:
136 case osg::PrimitiveSet::LINE_STRIP:
137 case osg::PrimitiveSet::LINE_LOOP:
138 case osg::PrimitiveSet::LINES_ADJACENCY:
139 case osg::PrimitiveSet::LINE_STRIP_ADJACENCY:
140 break;
141
142 default: OSG_WARN << "Warning: TangentSpaceGenerator: unknown primitive mode " << pset->getMode() << "\n";
143 }
144 }
145
146 // normalize basis vectors and force the normal vector to match
147 // the triangle normal's direction
148 unsigned int attrib_count = vx->getNumElements();
149 for (i=0; i<attrib_count; ++i) {
150 osg::Vec4 &vT = (*T_)[i];
151 osg::Vec4 &vB = (*B_)[i];
152 osg::Vec4 &vN = (*N_)[i];
153
154 osg::Vec3 txN = osg::Vec3(vT.x(), vT.y(), vT.z()) ^ osg::Vec3(vB.x(), vB.y(), vB.z());
155 bool flipped = txN * osg::Vec3(vN.x(), vN.y(), vN.z()) < 0;
156
157 if (flipped) {
158 vN = osg::Vec4(-txN, 0);
159 } else {
160 vN = osg::Vec4(txN, 0);
161 }
162
163 vT.normalize();
164 vB.normalize();
165 vN.normalize();
166
167 vT[3] = flipped ? -1.0f : 1.0f;
168 }
169 /* TO-DO: if indexed, compress the attributes to have only one
170 * version of each (different indices for each one?) */
171 }
172
compute(osg::PrimitiveSet * pset,const osg::Array * vx,const osg::Array * nx,const osg::Array * tx,int iA,int iB,int iC)173 void TangentSpaceGenerator::compute(osg::PrimitiveSet *pset,
174 const osg::Array* vx,
175 const osg::Array* nx,
176 const osg::Array* tx,
177 int iA, int iB, int iC)
178 {
179 iA = pset->index(iA);
180 iB = pset->index(iB);
181 iC = pset->index(iC);
182
183 osg::Vec3 P1;
184 osg::Vec3 P2;
185 osg::Vec3 P3;
186
187 int i; // VC6 doesn't like for-scoped variables
188
189 switch (vx->getType())
190 {
191 case osg::Array::Vec2ArrayType:
192 for (i=0; i<2; ++i) {
193 P1.ptr()[i] = static_cast<const osg::Vec2Array&>(*vx)[iA].ptr()[i];
194 P2.ptr()[i] = static_cast<const osg::Vec2Array&>(*vx)[iB].ptr()[i];
195 P3.ptr()[i] = static_cast<const osg::Vec2Array&>(*vx)[iC].ptr()[i];
196 }
197 break;
198
199 case osg::Array::Vec3ArrayType:
200 P1 = static_cast<const osg::Vec3Array&>(*vx)[iA];
201 P2 = static_cast<const osg::Vec3Array&>(*vx)[iB];
202 P3 = static_cast<const osg::Vec3Array&>(*vx)[iC];
203 break;
204
205 case osg::Array::Vec4ArrayType:
206 for (i=0; i<3; ++i) {
207 P1.ptr()[i] = static_cast<const osg::Vec4Array&>(*vx)[iA].ptr()[i];
208 P2.ptr()[i] = static_cast<const osg::Vec4Array&>(*vx)[iB].ptr()[i];
209 P3.ptr()[i] = static_cast<const osg::Vec4Array&>(*vx)[iC].ptr()[i];
210 }
211 break;
212
213 default:
214 OSG_WARN << "Warning: TangentSpaceGenerator: vertex array must be Vec2Array, Vec3Array or Vec4Array" << std::endl;
215 }
216
217 osg::Vec3 N1;
218 osg::Vec3 N2;
219 osg::Vec3 N3;
220
221 if(nx)
222 {
223 switch (nx->getType())
224 {
225 case osg::Array::Vec2ArrayType:
226 for (i=0; i<2; ++i) {
227 N1.ptr()[i] = static_cast<const osg::Vec2Array&>(*nx)[iA].ptr()[i];
228 N2.ptr()[i] = static_cast<const osg::Vec2Array&>(*nx)[iB].ptr()[i];
229 N3.ptr()[i] = static_cast<const osg::Vec2Array&>(*nx)[iC].ptr()[i];
230 }
231 break;
232
233 case osg::Array::Vec3ArrayType:
234 N1 = static_cast<const osg::Vec3Array&>(*nx)[iA];
235 N2 = static_cast<const osg::Vec3Array&>(*nx)[iB];
236 N3 = static_cast<const osg::Vec3Array&>(*nx)[iC];
237 break;
238
239 case osg::Array::Vec4ArrayType:
240 for (i=0; i<3; ++i) {
241 N1.ptr()[i] = static_cast<const osg::Vec4Array&>(*nx)[iA].ptr()[i];
242 N2.ptr()[i] = static_cast<const osg::Vec4Array&>(*nx)[iB].ptr()[i];
243 N3.ptr()[i] = static_cast<const osg::Vec4Array&>(*nx)[iC].ptr()[i];
244 }
245 break;
246
247 default:
248 OSG_WARN << "Warning: TangentSpaceGenerator: normal array must be Vec2Array, Vec3Array or Vec4Array" << std::endl;
249 }
250 }
251
252 osg::Vec2 uv1;
253 osg::Vec2 uv2;
254 osg::Vec2 uv3;
255
256 switch (tx->getType())
257 {
258 case osg::Array::Vec2ArrayType:
259 uv1 = static_cast<const osg::Vec2Array&>(*tx)[iA];
260 uv2 = static_cast<const osg::Vec2Array&>(*tx)[iB];
261 uv3 = static_cast<const osg::Vec2Array&>(*tx)[iC];
262 break;
263
264 case osg::Array::Vec3ArrayType:
265 for (i=0; i<2; ++i) {
266 uv1.ptr()[i] = static_cast<const osg::Vec3Array&>(*tx)[iA].ptr()[i];
267 uv2.ptr()[i] = static_cast<const osg::Vec3Array&>(*tx)[iB].ptr()[i];
268 uv3.ptr()[i] = static_cast<const osg::Vec3Array&>(*tx)[iC].ptr()[i];
269 }
270 break;
271
272 case osg::Array::Vec4ArrayType:
273 for (i=0; i<2; ++i) {
274 uv1.ptr()[i] = static_cast<const osg::Vec4Array&>(*tx)[iA].ptr()[i];
275 uv2.ptr()[i] = static_cast<const osg::Vec4Array&>(*tx)[iB].ptr()[i];
276 uv3.ptr()[i] = static_cast<const osg::Vec4Array&>(*tx)[iC].ptr()[i];
277 }
278 break;
279
280 default:
281 OSG_WARN << "Warning: TangentSpaceGenerator: texture coord array must be Vec2Array, Vec3Array or Vec4Array" << std::endl;
282 }
283
284 osg::Vec3 V, T1, T2, T3, B1, B2, B3;
285
286 // no normal per vertex use the one by face
287 if (!nx) {
288 N1 = (P2 - P1) ^ (P3 - P1);
289 N2 = N1;
290 N3 = N1;
291 }
292
293 V = osg::Vec3(P2.x() - P1.x(), uv2.x() - uv1.x(), uv2.y() - uv1.y()) ^
294 osg::Vec3(P3.x() - P1.x(), uv3.x() - uv1.x(), uv3.y() - uv1.y());
295 if (V.x() != 0) {
296 V.normalize();
297 T1.x() += -V.y() / V.x();
298 B1.x() += -V.z() / V.x();
299 T2.x() += -V.y() / V.x();
300 B2.x() += -V.z() / V.x();
301 T3.x() += -V.y() / V.x();
302 B3.x() += -V.z() / V.x();
303 }
304
305 V = osg::Vec3(P2.y() - P1.y(), uv2.x() - uv1.x(), uv2.y() - uv1.y()) ^
306 osg::Vec3(P3.y() - P1.y(), uv3.x() - uv1.x(), uv3.y() - uv1.y());
307 if (V.x() != 0) {
308 V.normalize();
309 T1.y() += -V.y() / V.x();
310 B1.y() += -V.z() / V.x();
311 T2.y() += -V.y() / V.x();
312 B2.y() += -V.z() / V.x();
313 T3.y() += -V.y() / V.x();
314 B3.y() += -V.z() / V.x();
315 }
316
317 V = osg::Vec3(P2.z() - P1.z(), uv2.x() - uv1.x(), uv2.y() - uv1.y()) ^
318 osg::Vec3(P3.z() - P1.z(), uv3.x() - uv1.x(), uv3.y() - uv1.y());
319 if (V.x() != 0) {
320 V.normalize();
321 T1.z() += -V.y() / V.x();
322 B1.z() += -V.z() / V.x();
323 T2.z() += -V.y() / V.x();
324 B2.z() += -V.z() / V.x();
325 T3.z() += -V.y() / V.x();
326 B3.z() += -V.z() / V.x();
327 }
328
329 osg::Vec3 tempvec;
330
331 tempvec = N1 ^ T1;
332 (*T_)[iA] += osg::Vec4(tempvec ^ N1, 0);
333
334 tempvec = B1 ^ N1;
335 (*B_)[iA] += osg::Vec4(N1 ^ tempvec, 0);
336
337 tempvec = N2 ^ T2;
338 (*T_)[iB] += osg::Vec4(tempvec ^ N2, 0);
339
340 tempvec = B2 ^ N2;
341 (*B_)[iB] += osg::Vec4(N2 ^ tempvec, 0);
342
343 tempvec = N3 ^ T3;
344 (*T_)[iC] += osg::Vec4(tempvec ^ N3, 0);
345
346 tempvec = B3 ^ N3;
347 (*B_)[iC] += osg::Vec4(N3 ^ tempvec, 0);
348
349 (*N_)[iA] += osg::Vec4(N1, 0);
350 (*N_)[iB] += osg::Vec4(N2, 0);
351 (*N_)[iC] += osg::Vec4(N3, 0);
352
353 }
354
355