clray: 51f115e337c2 src/scene

clray

view src/scene_obj.cc @ 23:51f115e337c2

separated obj loading and vector class

author	John Tsiombikas <nuclear@member.fsf.org>
date	Fri, 13 Aug 2010 18:20:45 +0100
parents
children	0f174fd60f19

line source

1 #include <stdio.h>

2 #include <stdlib.h>

3 #include <string.h>

4 #include <errno.h>

5 #include <ctype.h>

6 #include <limits.h>

7 #include <string>

8 #include <vector>

9 #include <map>

10 #include "scene.h"

11 #include "vector.h"

13 #ifndef PATH_MAX

14 #define PATH_MAX 512

15 #endif

17 #define COMMANDS \

18 CMD(V), \

19 CMD(VN), \

20 CMD(VT), \

21 CMD(F), \

22 CMD(O), \

23 CMD(G), \

24 CMD(MTLLIB), \

25 CMD(USEMTL), \

26 CMD(NEWMTL), \

27 CMD(KA), \

28 CMD(KD), \

29 CMD(KS), \

30 CMD(KR), \

31 CMD(NS), \

32 CMD(NI), \

33 CMD(D), \

34 CMD(TR), \

35 CMD(MAP_KD), \

36 CMD(MAP_KS), \

37 CMD(MAP_NS), \

38 CMD(MAP_D), \

39 CMD(REFL), \

40 CMD(BUMP)

42 #define CMD(x) CMD_##x

43 enum {

44 COMMANDS,

45 CMD_UNK

46 };

47 #undef CMD

49 #define CMD(x) #x

50 static const char *cmd_names[] = {

51 COMMANDS,

52 0

53 };

54 #undef CMD

56 struct obj_face {

57 int elem;

58 int v[4], n[4], t[4];

59 };

61 struct obj_file {

62 std::string cur_obj, cur_mat;

63 std::vector<Vector3> v, vn, vt;

64 std::vector<obj_face> f;

65 };

67 struct obj_mat {

68 std::string name; // newmtl <name>

69 Vector3 ambient, diffuse, specular; // Ka, Kd, Ks

70 float shininess; // Ns

71 float ior; // Ni

72 float alpha; // d, Tr

73 float refl; // Kr (my extesnsion)

75 std::string tex_dif, tex_spec, tex_shin, tex_alpha; // map_Kd, map_Ks, map_Ns, map_d

76 std::string tex_refl; // refl -type sphere|cube file

77 std::string tex_bump; // bump

79 obj_mat() { reset(); }

81 void reset() {

82 ambient = diffuse = Vector3(0.5, 0.5, 0.5);

83 specular = Vector3(0.0, 0.0, 0.0);

84 name = tex_dif = tex_spec = tex_shin = tex_alpha = tex_refl = tex_bump = "";

85 shininess = 0;

86 ior = alpha = 1;

87 refl = 0.0;

88 }

89 };

91 static bool read_materials(FILE *fp, std::vector<obj_mat> *vmtl);

92 static Mesh *cons_mesh(obj_file *obj);

94 static int get_cmd(char *str);

95 static bool is_int(const char *str);

96 static bool is_float(const char *str);

97 static bool parse_vec(Vector3 *vec);

98 static bool parse_color(Vector3 *col);

99 static bool parse_face(obj_face *face);

100 static const char *parse_map();

101

102 static bool find_file(char *res, int sz, const char *fname, const char *path = ".", const char *mode = "rb");

103 static const char *dirname(const char *str);

104

105 static std::map<std::string, int> matnames;

106

107 #define INVALID_IDX INT_MIN

108

109 #define SEP " \t\n\r\v"

110 #define BUF_SZ 512

111

112

113 bool Scene::load(const char *fname)

114 {

115 FILE *fp;

116

117 if(!(fp = fopen(fname, "rb"))) {

118 fprintf(stderr, "failed to open %s: %s\n", fname, strerror(errno));

119 return false;

120 }

121

122 bool res = load(fp);

123 fclose(fp);

124 return res;

125 }

126

127 bool Scene::load(FILE *fp)

128 {

129 static int seq;

130 char cur_name[16];

131

132 obj_file obj;

133

134 sprintf(cur_name, "default%02d.obj", seq++);

135 obj.cur_obj = cur_name;

136

137 int prev_cmd = 0, obj_added = 0;

138 for(;;) {

139 Vector3 vec;

140 obj_face face;

141

142 char line[BUF_SZ];

143 fgets(line, sizeof line, fp);

144 if(feof(fp)) {

145 break;

146 }

147

148 char *tok;

149 if(!(tok = strtok(line, SEP))) {

150 continue; // ignore empty lines

151 }

152

153 int cmd;

154 if((cmd = get_cmd(tok)) == -1) {

155 continue; // ignore unknown commands ...

156 }

157

158 switch(cmd) {

159 case CMD_V:

160 if(!parse_vec(&vec)) {

161 continue;

162 }

163 obj.v.push_back(vec);

164 break;

165

166 case CMD_VN:

167 if(!parse_vec(&vec)) {

168 continue;

169 }

170 obj.vn.push_back(vec);

171 break;

172

173 case CMD_VT:

174 if(!parse_vec(&vec)) {

175 continue;

176 }

177 vec.y = 1.0 - vec.y;

178 obj.vt.push_back(vec);

179 break;

180

181 case CMD_O:

182 case CMD_G:

183 if(prev_cmd == CMD_O || prev_cmd == CMD_G) {

184 break; // just in case we've got both of them in a row

185 }

186 /* if we have any previous data, group them up, add the object

187 * and continue with the new one...

188 */

189 if(!obj.f.empty()) {

190 Mesh *mesh = cons_mesh(&obj);

191 mesh->matid = matnames[obj.cur_mat];

192 add_mesh(mesh);

193 obj_added++;

194

195 obj.f.clear(); // clean the face list

196 }

197 if((tok = strtok(0, SEP))) {

198 obj.cur_obj = tok;

199 } else {

200 sprintf(cur_name, "default%02d.obj", seq++);

201 obj.cur_obj = cur_name;

202 }

203 break;

204

205 case CMD_MTLLIB:

206 if((tok = strtok(0, SEP))) {

207 char path[PATH_MAX];

208

209 sprintf(path, ".:%s", dirname(tok));

210 if(!find_file(path, PATH_MAX, tok, path)) {

211 fprintf(stderr, "material library not found: %s\n", tok);

212 continue;

213 }

214

215 FILE *mfile;

216 if(!(mfile = fopen(path, "rb"))) {

217 fprintf(stderr, "failed to open material library: %s\n", path);

218 continue;

219 }

220

221 // load all materials of the mtl file into a vector

222 std::vector<obj_mat> vmtl;

223 if(!read_materials(mfile, &vmtl)) {

224 continue;

225 }

226 fclose(mfile);

227

228 // and add them all to the scene

229 for(size_t i=0; i<vmtl.size(); i++) {

230 Material mat;

231

232 mat.kd[0] = vmtl[i].diffuse.x;

233 mat.kd[1] = vmtl[i].diffuse.y;

234 mat.kd[2] = vmtl[i].diffuse.z;

235

236 mat.ks[0] = vmtl[i].specular.x;

237 mat.ks[1] = vmtl[i].specular.y;

238 mat.ks[2] = vmtl[i].specular.z;

239

240 mat.kt = 1.0 - vmtl[i].alpha;

241 mat.kr = vmtl[i].refl;

242 mat.spow = vmtl[i].shininess;

243

244 matlib.push_back(mat);

245 matnames[vmtl[i].name] = i;

246 }

247 }

248 break;

249

250 case CMD_USEMTL:

251 if((tok = strtok(0, SEP))) {

252 obj.cur_mat = tok;

253 } else {

254 obj.cur_mat = "";

255 }

256 break;

257

258 case CMD_F:

259 if(!parse_face(&face)) {

260 continue;

261 }

262

263 // convert negative indices to regular indices

264 for(int i=0; i<4; i++) {

265 if(face.v[i] < 0 && face.v[i] != INVALID_IDX) {

266 face.v[i] = obj.v.size() + face.v[i];

267 }

268 if(face.n[i] < 0 && face.n[i] != INVALID_IDX) {

269 face.n[i] = obj.vn.size() + face.n[i];

270 }

271 if(face.t[i] < 0 && face.t[i] != INVALID_IDX) {

272 face.t[i] = obj.vt.size() + face.t[i];

273 }

274 }

275

276 // break quads into triangles if needed

277 obj.f.push_back(face);

278 if(face.elem == 4) {

279 face.v[1] = face.v[2];

280 face.n[1] = face.n[2];

281 face.t[1] = face.t[2];

282

283 face.v[2] = face.v[3];

284 face.n[2] = face.n[3];

285 face.t[2] = face.t[3];

286

287 obj.f.push_back(face);

288 }

289 break;

290

291 default:

292 break; // ignore unknown commands

293 }

294

295 prev_cmd = cmd;

296 }

297

298 // reached end of file...

299 if(!obj.f.empty()) {

300 Mesh *mesh = cons_mesh(&obj);

301 mesh->matid = matnames[obj.cur_mat];

302 add_mesh(mesh);

303 obj_added++;

304 }

305

306 return obj_added > 0;

307 }

308

309 static Mesh *cons_mesh(obj_file *obj)

310 {

311 Mesh *mesh;

312

313 // need at least one of each element

314 bool added_norm = false, added_tc = false;

315 if(obj->vn.empty()) {

316 obj->vn.push_back(Vector3(0, 0, 0));

317 added_norm = true;

318 }

319 if(obj->vt.empty()) {

320 obj->vt.push_back(Vector3(0, 0, 0));

321 added_tc = true;

322 }

323

324 mesh = new Mesh;

325

326 for(size_t i=0; i<obj->f.size(); i++) {

327 Face face;

328 Vector3 v[3];

329

330 for(int j=0; j<3; j++) {

331 obj_face *f = &obj->f[i];

332

333 face.v[j].pos[0] = v[j].x = obj->v[f->v[j]].x;

334 face.v[j].pos[1] = v[j].y = obj->v[f->v[j]].y;

335 face.v[j].pos[2] = v[j].z = obj->v[f->v[j]].z;

336 face.v[j].pos[3] = 0.0;

337

338 int nidx = f->n[j] < 0 ? 0 : f->n[j];

339 face.v[j].normal[0] = obj->vn[nidx].x;

340 face.v[j].normal[1] = obj->vn[nidx].y;

341 face.v[j].normal[2] = obj->vn[nidx].z;

342 face.v[j].normal[3] = 0.0;

343

344 int tidx = f->t[j] < 0 ? 0 : f->t[j];

345 face.v[j].tex[0] = obj->vt[tidx].x;

346 face.v[j].tex[1] = obj->vt[tidx].y;

347 }

348

349 Vector3 a = v[1] - v[0];

350 Vector3 b = v[2] - v[0];

351 Vector3 n = cross(a, b);

352 n.normalize();

353

354 face.normal[0] = n.x;

355 face.normal[1] = n.y;

356 face.normal[2] = n.z;

357 face.normal[3] = 0.0;

358

359 mesh->faces.push_back(face);

360 }

361

362 if(added_norm) {

363 obj->vn.pop_back();

364 }

365 if(added_tc) {

366 obj->vt.pop_back();

367 }

368

369 return mesh;

370 }

371

372 static bool read_materials(FILE *fp, std::vector<obj_mat> *vmtl)

373 {

374 obj_mat mat;

375

376 for(;;) {

377 char line[BUF_SZ];

378 fgets(line, sizeof line, fp);

379 if(feof(fp)) {

380 break;

381 }

382

383 char *tok;

384 if(!(tok = strtok(line, SEP))) {

385 continue;

386 }

387

388 int cmd;

389 if((cmd = get_cmd(tok)) == -1) {

390 continue;

391 }

392

393 switch(cmd) {

394 case CMD_NEWMTL:

395 // add the previous material, and start a new one

396 if(mat.name.length() > 0) {

397 printf("Adding material: %s\n", mat.name.c_str());

398 vmtl->push_back(mat);

399 mat.reset();

400 }

401 if((tok = strtok(0, SEP))) {

402 mat.name = tok;

403 }

404 break;

405

406 case CMD_KA:

407 parse_color(&mat.ambient);

408 break;

409

410 case CMD_KD:

411 parse_color(&mat.diffuse);

412 break;

413

414 case CMD_KS:

415 parse_color(&mat.specular);

416 break;

417

418 case CMD_KR:

419 if((tok = strtok(0, SEP)) && is_float(tok)) {

420 mat.refl = atof(tok);

421 }

422 break;

423

424 case CMD_NS:

425 if((tok = strtok(0, SEP)) && is_float(tok)) {

426 mat.shininess = atof(tok);

427 }

428 break;

429

430 case CMD_NI:

431 if((tok = strtok(0, SEP)) && is_float(tok)) {

432 mat.ior = atof(tok);

433 }

434 break;

435

436 case CMD_D:

437 case CMD_TR:

438 {

439 Vector3 c;

440 if(parse_color(&c)) {

441 mat.alpha = cmd == CMD_D ? c.x : 1.0 - c.x;

442 }

443 }

444 break;

445

446 case CMD_MAP_KD:

447 mat.tex_dif = parse_map();

448 break;

449

450 default:

451 break;

452 }

453 }

454

455 if(mat.name.length() > 0) {

456 printf("Adding material: %s\n", mat.name.c_str());

457 vmtl->push_back(mat);

458 }

459 return true;

460 }

461

462 static int get_cmd(char *str)

463 {

464 char *s = str;

465 while((*s = toupper(*s))) s++;

466

467 for(int i=0; cmd_names[i]; i++) {

468 if(strcmp(str, cmd_names[i]) == 0) {

469 return i;

470 }

471 }

472 return CMD_UNK;

473 }

474

475 static bool is_int(const char *str)

476 {

477 char *tmp;

478 strtol(str, &tmp, 10);

479 return tmp != str;

480 }

481

482 static bool is_float(const char *str)

483 {

484 char *tmp;

485 strtod(str, &tmp);

486 return tmp != str;

487 }

488

489 static bool parse_vec(Vector3 *vec)

490 {

491 for(int i=0; i<3; i++) {

492 char *tok;

493

494 if(!(tok = strtok(0, SEP)) || !is_float(tok)) {

495 if(i < 2) {

496 return false;

497 }

498 vec->z = 0.0;

499 } else {

500 float v = atof(tok);

501

502 switch(i) {

503 case 0:

504 vec->x = v;

505 break;

506 case 1:

507 vec->y = v;

508 break;

509 case 2:

510 vec->z = v;

511 break;

512 }

513 }

514 }

515 return true;

516 }

517

518 static bool parse_color(Vector3 *col)

519 {

520 for(int i=0; i<3; i++) {

521 char *tok;

522

523 if(!(tok = strtok(0, SEP)) || !is_float(tok)) {

524 col->y = col->z = col->x;

525 return i > 0 ? true : false;

526 }

527

528 float v = atof(tok);

529 switch(i) {

530 case 0:

531 col->x = v;

532 break;

533 case 1:

534 col->y = v;

535 break;

536 case 2:

537 col->z = v;

538 break;

539 }

540 }

541 return true;

542 }

543

544 static bool parse_face(obj_face *face)

545 {

546 char *tok[] = {0, 0, 0, 0};

547 face->elem = 0;

548

549 for(int i=0; i<4; i++) {

550 if((!(tok[i] = strtok(0, SEP)) || !is_int(tok[i]))) {

551 if(i < 3) return false; // less than 3 verts? not a polygon

552 } else {

553 face->elem++;

554 }

555 }

556

557 for(int i=0; i<4; i++) {

558 char *subtok = tok[i];

559

560 if(!subtok || !*subtok || !is_int(subtok)) {

561 if(i < 3) {

562 return false;

563 }

564 face->v[i] = INVALID_IDX;

565 } else {

566 face->v[i] = atoi(subtok);

567 if(face->v[i] > 0) face->v[i]--; /* convert to 0-based */

568 }

569

570 while(subtok && *subtok && *subtok != '/') {

571 subtok++;

572 }

573 if(subtok && *subtok && *++subtok && is_int(subtok)) {

574 face->t[i] = atoi(subtok);

575 if(face->t[i] > 0) face->t[i]--; /* convert to 0-based */

576 } else {

577 face->t[i] = INVALID_IDX;

578 }

579

580 while(subtok && *subtok && *subtok != '/') {

581 subtok++;

582 }

583 if(subtok && *subtok && *++subtok && is_int(subtok)) {

584 face->n[i] = atoi(subtok);

585 if(face->n[i] > 0) face->n[i]--; /* convert to 0-based */

586 } else {

587 face->n[i] = INVALID_IDX;

588 }

589 }

590

591 return true;

592 }

593

594 static const char *parse_map()

595 {

596 char *tok, *prev = 0;

597

598 while((tok = strtok(0, SEP))) {

599 prev = tok;

600 }

601

602 return prev ? prev : "";

603 }

604

605 static bool find_file(char *res, int sz, const char *fname, const char *path, const char *mode)

606 {

607 FILE *fp;

608 const char *beg, *end;

609 int fnamelen = strlen(fname);

610

611 beg = path;

612 while(beg && *beg) {

613 end = beg;

614 while(*end && *end != ':') {

615 end++;

616 }

617

618 int res_len = end - beg;

619 char *pathname = (char*)alloca(res_len + fnamelen + 2);

620 memcpy(pathname, beg, res_len);

621 pathname[res_len] = 0;

622 if(res_len) {

623 strcat(pathname, "/");

624 }

625 strcat(pathname, fname);

626

627 if((fp = fopen(pathname, mode))) {

628 fclose(fp);

629 strncpy(res, pathname, sz);

630 return true;

631 }

632

633 beg += res_len;

634 if(*beg == ':') beg++;

635 }

636 return false;

637 }

638

639 static const char *dirname(const char *str)

640 {

641 static char buf[PATH_MAX];

642

643 if(!str || !*str) {

644 strcpy(buf, ".");

645 } else {

646 strncpy(buf, str, PATH_MAX);

647 char *ptr = strrchr(buf, '/');

648

649 if(ptr && *ptr) {

650 *ptr = 0;

651 } else {

652 strcpy(buf, ".");

653 }

654 }

655 return buf;

656 }