Source:SLASH'EM 0.0.7E7F2/light.c
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Below is the full text to light.c from the source code of SLASH'EM 0.0.7E7F2. To link to a particular line, write [[Source:SLASH'EM 0.0.7E7F2/light.c#line123]], for example.
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1. /* SCCS Id: @(#)light.c 3.4 1997/04/10 */ 2. /* Copyright (c) Dean Luick, 1994 */ 3. /* NetHack may be freely redistributed. See license for details. */ 4. 5. #include "hack.h" 6. #include "lev.h" /* for checking save modes */ 7. 8. /* 9. * Mobile light sources. 10. * 11. * This implementation minimizes memory at the expense of extra 12. * recalculations. 13. * 14. * Light sources are "things" that have a physical position and range. 15. * They have a type, which gives us information about them. Currently 16. * they are only attached to objects and monsters. Note well: the 17. * polymorphed-player handling assumes that both youmonst.m_id and 18. * youmonst.mx will always remain 0. 19. * 20. * Light sources, like timers, either follow game play (RANGE_GLOBAL) or 21. * stay on a level (RANGE_LEVEL). Light sources are unique by their 22. * (type, id) pair. For light sources attached to objects, this id 23. * is a pointer to the object. 24. * 25. * The major working function is do_light_sources(). It is called 26. * when the vision system is recreating its "could see" array. Here 27. * we add a flag (TEMP_LIT) to the array for all locations that are lit 28. * via a light source. The bad part of this is that we have to 29. * re-calculate the LOS of each light source every time the vision 30. * system runs. Even if the light sources and any topology (vision blocking 31. * positions) have not changed. The good part is that no extra memory 32. * is used, plus we don't have to figure out how far the sources have moved, 33. * or if the topology has changed. 34. * 35. * The structure of the save/restore mechanism is amazingly similar to 36. * the timer save/restore. This is because they both have the same 37. * principals of having pointers into objects that must be recalculated 38. * across saves and restores. 39. */ 40. 41. #ifdef OVL3 42. 43. /* flags */ 44. #define LSF_SHOW 0x1 /* display the light source */ 45. #define LSF_NEEDS_FIXUP 0x2 /* need oid fixup */ 46. #define LSF_FLOATING 0x4 /* location not yet determined */ 47. 48. static light_source *light_base = 0; 49. 50. STATIC_DCL void FDECL(write_ls, (int, light_source *)); 51. STATIC_DCL int FDECL(maybe_write_ls, (int, int, BOOLEAN_P)); 52. 53. /* imported from vision.c, for small circles */ 54. extern char circle_data[]; 55. extern char circle_start[]; 56. 57. /* WAC in artifact.c, for obj_sheds_light*/ 58. extern boolean FDECL(obj_special_light, (struct obj *)); 59. 60. /* Create a new light source. */ 61. void 62. new_light_source(x, y, range, type, id) 63. xchar x, y; 64. int range, type; 65. genericptr_t id; 66. { 67. light_source *ls; 68. 69. if (range > MAX_RADIUS || range < 1) { 70. impossible("new_light_source: illegal range %d", range); 71. return; 72. } 73. 74. ls = (light_source *) alloc(sizeof(light_source)); 75. 76. ls->next = light_base; 77. ls->x = x; 78. ls->y = y; 79. ls->range = range; 80. ls->type = type; 81. ls->id = id; 82. if (ls->type != LS_TEMP && x == 0) 83. ls->flags = LSF_FLOATING; 84. else 85. ls->flags = 0; 86. light_base = ls; 87. 88. vision_full_recalc = 1; /* make the source show up */ 89. } 90. 91. /* 92. * Delete a light source. This assumes only one light source is attached 93. * to an object at a time. 94. */ 95. void 96. del_light_source(type, id) 97. int type; 98. genericptr_t id; 99. { 100. light_source *curr, *prev; 101. genericptr_t tmp_id; 102. 103. /* need to be prepared for dealing a with light source which 104. has only been partially restored during a level change 105. (in particular: chameleon vs prot. from shape changers) */ 106. switch (type) { 107. case LS_OBJECT: tmp_id = (genericptr_t)(((struct obj *)id)->o_id); 108. break; 109. case LS_MONSTER: tmp_id = (genericptr_t)(((struct monst *)id)->m_id); 110. break; 111. case LS_TEMP: tmp_id = id; 112. break; 113. default: tmp_id = 0; 114. break; 115. } 116. 117. for (prev = 0, curr = light_base; curr; prev = curr, curr = curr->next) { 118. if (curr->type != type) continue; 119. if (curr->id == ((curr->flags & LSF_NEEDS_FIXUP) ? tmp_id : id)) 120. { 121. if (prev) 122. prev->next = curr->next; 123. else 124. light_base = curr->next; 125. 126. free((genericptr_t)curr); 127. vision_full_recalc = 1; 128. return; 129. } 130. } 131. impossible("del_light_source: not found type=%d, id=0x%lx", type, (long)id); 132. } 133. 134. /* Mark locations that are temporarily lit via mobile light sources. */ 135. void 136. do_light_sources(cs_rows) 137. char **cs_rows; 138. { 139. int x, y, min_x, max_x, max_y, offset; 140. char *limits; 141. short at_hero_range = 0; 142. light_source *ls; 143. char *row; 144. 145. for (ls = light_base; ls; ls = ls->next) { 146. ls->flags &= ~LSF_SHOW; 147. 148. /* 149. * See if floating light source has been finalized yet. 150. * If not, arrange for vision to be recalculated later. 151. */ 152. if (ls->flags & LSF_FLOATING) { 153. if (ls->type == LS_OBJECT) { 154. if (get_obj_location((struct obj *) ls->id, &ls->x, &ls->y, 155. CONTAINED_TOO | BURIED_TOO)) 156. ls->flags &= ~LSF_FLOATING; 157. } else if (ls->type == LS_MONSTER) { 158. if (get_mon_location((struct monst *) ls->id, &ls->x, &ls->y, 159. CONTAINED_TOO | BURIED_TOO)) 160. ls->flags &= ~LSF_FLOATING; 161. } 162. if (ls->flags & LSF_FLOATING) { 163. vision_full_recalc = 1; 164. continue; 165. } 166. } 167. /* 168. * Check for moved light sources. It may be possible to 169. * save some effort if an object has not moved, but not in 170. * the current setup -- we need to recalculate for every 171. * vision recalc. 172. */ 173. if (ls->type == LS_OBJECT) { 174. if (get_obj_location((struct obj *) ls->id, &ls->x, &ls->y, 0)) 175. ls->flags |= LSF_SHOW; 176. } else if (ls->type == LS_MONSTER) { 177. if (get_mon_location((struct monst *) ls->id, &ls->x, &ls->y, 0)) 178. ls->flags |= LSF_SHOW; 179. } else if (ls->type == LS_TEMP) { 180. ls->flags |= LSF_SHOW; 181. } 182. 183. /* minor optimization: don't bother with duplicate light sources */ 184. /* at hero */ 185. if (ls->x == u.ux && ls->y == u.uy) { 186. if (at_hero_range >= ls->range) 187. ls->flags &= ~LSF_SHOW; 188. else 189. at_hero_range = ls->range; 190. } 191. 192. if (ls->flags & LSF_SHOW) { 193. /* 194. * Walk the points in the circle and see if they are 195. * visible from the center. If so, mark'em. 196. * 197. * Kevin's tests indicated that doing this brute-force 198. * method is faster for radius <= 3 (or so). 199. */ 200. limits = circle_ptr(ls->range); 201. if ((max_y = (ls->y + ls->range)) >= ROWNO) max_y = ROWNO-1; 202. if ((y = (ls->y - ls->range)) < 0) y = 0; 203. for (; y <= max_y; y++) { 204. row = cs_rows[y]; 205. offset = limits[abs(y - ls->y)]; 206. if ((min_x = (ls->x - offset)) < 0) min_x = 0; 207. if ((max_x = (ls->x + offset)) >= COLNO) max_x = COLNO-1; 208. 209. if (ls->x == u.ux && ls->y == u.uy) { 210. /* 211. * If the light source is located at the hero, then 212. * we can use the COULD_SEE bits already calcualted 213. * by the vision system. More importantly than 214. * this optimization, is that it allows the vision 215. * system to correct problems with clear_path(). 216. * The function clear_path() is a simple LOS 217. * path checker that doesn't go out of its way 218. * make things look "correct". The vision system 219. * does this. 220. */ 221. for (x = min_x; x <= max_x; x++) 222. if (row[x] & COULD_SEE) 223. row[x] |= TEMP_LIT; 224. } else { 225. for (x = min_x; x <= max_x; x++) 226. if ((ls->x == x && ls->y == y) 227. || clear_path((int)ls->x, (int) ls->y, x, y)) 228. row[x] |= TEMP_LIT; 229. } 230. } 231. } 232. } 233. } 234. 235. /* (mon->mx == 0) implies migrating */ 236. #define mon_is_local(mon) ((mon)->mx > 0) 237. 238. struct monst * 239. find_mid(nid, fmflags) 240. unsigned nid; 241. unsigned fmflags; 242. { 243. struct monst *mtmp; 244. 245. if (!nid) 246. return &youmonst; 247. if (fmflags & FM_FMON) 248. for (mtmp = fmon; mtmp; mtmp = mtmp->nmon) 249. if (!DEADMONSTER(mtmp) && mtmp->m_id == nid) return mtmp; 250. if (fmflags & FM_MIGRATE) 251. for (mtmp = migrating_mons; mtmp; mtmp = mtmp->nmon) 252. if (mtmp->m_id == nid) return mtmp; 253. if (fmflags & FM_MYDOGS) 254. for (mtmp = mydogs; mtmp; mtmp = mtmp->nmon) 255. if (mtmp->m_id == nid) return mtmp; 256. return (struct monst *) 0; 257. } 258. 259. /* Save all light sources of the given range. */ 260. void 261. save_light_sources(fd, mode, range) 262. int fd, mode, range; 263. { 264. int count, actual, is_global; 265. light_source **prev, *curr; 266. 267. if (perform_bwrite(mode)) { 268. count = maybe_write_ls(fd, range, FALSE); 269. bwrite(fd, (genericptr_t) &count, sizeof count); 270. actual = maybe_write_ls(fd, range, TRUE); 271. if (actual != count) 272. panic("counted %d light sources, wrote %d! [range=%d]", 273. count, actual, range); 274. } 275. 276. if (release_data(mode)) { 277. for (prev = &light_base; (curr = *prev) != 0; ) { 278. if (!curr->id) { 279. impossible("save_light_sources: no id! [range=%d]", range); 280. is_global = 0; 281. } else 282. switch (curr->type) { 283. case LS_OBJECT: 284. is_global = !obj_is_local((struct obj *)curr->id); 285. break; 286. case LS_MONSTER: 287. is_global = !mon_is_local((struct monst *)curr->id); 288. break; 289. case LS_TEMP: 290. /* Temp light sources should never be saved, but need to 291. * set next (or else you get caught in an infinite loop 292. */ 293. prev = &(*prev)->next; 294. continue; 295. default: 296. is_global = 0; 297. impossible("save_light_sources: bad type (%d) [range=%d]", 298. curr->type, range); 299. break; 300. } 301. /* if global and not doing local, or vice versa, remove it */ 302. if (is_global ^ (range == RANGE_LEVEL)) { 303. *prev = curr->next; 304. free((genericptr_t)curr); 305. } else { 306. prev = &(*prev)->next; 307. } 308. } 309. } 310. } 311. 312. /* 313. * Pull in the structures from disk, but don't recalculate the object 314. * pointers. 315. */ 316. void 317. restore_light_sources(fd) 318. int fd; 319. { 320. int count; 321. light_source *ls; 322. 323. /* restore elements */ 324. mread(fd, (genericptr_t) &count, sizeof count); 325. 326. while (count-- > 0) { 327. ls = (light_source *) alloc(sizeof(light_source)); 328. mread(fd, (genericptr_t) ls, sizeof(light_source)); 329. ls->next = light_base; 330. light_base = ls; 331. } 332. } 333. 334. /* Relink all lights that are so marked. */ 335. void 336. relink_light_sources(ghostly) 337. boolean ghostly; 338. { 339. char which; 340. unsigned nid; 341. light_source *ls; 342. 343. for (ls = light_base; ls; ls = ls->next) { 344. if (ls->flags & LSF_NEEDS_FIXUP) { 345. if (ls->type == LS_OBJECT || ls->type == LS_MONSTER) { 346. if (ghostly) { 347. if (!lookup_id_mapping((unsigned)ls->id, &nid)) 348. impossible("relink_light_sources: no id mapping"); 349. } else 350. nid = (unsigned) ls->id; 351. if (ls->type == LS_OBJECT) { 352. which = 'o'; 353. ls->id = (genericptr_t) find_oid(nid); 354. } else { 355. which = 'm'; 356. ls->id = (genericptr_t) find_mid(nid, FM_EVERYWHERE); 357. } 358. if (!ls->id) 359. impossible("relink_light_sources: cant find %c_id %d", 360. which, nid); 361. } else 362. impossible("relink_light_sources: bad type (%d)", ls->type); 363. 364. ls->flags &= ~LSF_NEEDS_FIXUP; 365. } 366. } 367. } 368. 369. /* 370. * Part of the light source save routine. Count up the number of light 371. * sources that would be written. If write_it is true, actually write 372. * the light source out. 373. */ 374. STATIC_OVL int 375. maybe_write_ls(fd, range, write_it) 376. int fd, range; 377. boolean write_it; 378. { 379. int count = 0, is_global; 380. light_source *ls; 381. 382. for (ls = light_base; ls; ls = ls->next) { 383. if (!ls->id) { 384. impossible("maybe_write_ls: no id! [range=%d]", range); 385. continue; 386. } 387. switch (ls->type) { 388. case LS_OBJECT: 389. is_global = !obj_is_local((struct obj *)ls->id); 390. break; 391. case LS_MONSTER: 392. is_global = !mon_is_local((struct monst *)ls->id); 393. break; 394. case LS_TEMP: 395. continue; 396. default: 397. is_global = 0; 398. impossible("maybe_write_ls: bad type (%d) [range=%d]", 399. ls->type, range); 400. break; 401. } 402. /* if global and not doing local, or vice versa, count it */ 403. if (is_global ^ (range == RANGE_LEVEL)) { 404. count++; 405. if (write_it) write_ls(fd, ls); 406. } 407. } 408. 409. return count; 410. } 411. 412. /* Write a light source structure to disk. */ 413. STATIC_OVL void 414. write_ls(fd, ls) 415. int fd; 416. light_source *ls; 417. { 418. genericptr_t arg_save; 419. struct obj *otmp; 420. struct monst *mtmp; 421. 422. if (ls->type == LS_OBJECT || ls->type == LS_MONSTER) { 423. if (ls->flags & LSF_NEEDS_FIXUP) 424. bwrite(fd, (genericptr_t)ls, sizeof(light_source)); 425. else { 426. /* replace object pointer with id for write, then put back */ 427. arg_save = ls->id; 428. if (ls->type == LS_OBJECT) { 429. otmp = (struct obj *)ls->id; 430. ls->id = (genericptr_t)otmp->o_id; 431. #ifdef DEBUG 432. if (find_oid((unsigned)ls->id) != otmp) 433. panic("write_ls: can't find obj #%u!", (unsigned)ls->id); 434. #endif 435. } else { /* ls->type == LS_MONSTER */ 436. mtmp = (struct monst *)ls->id; 437. ls->id = (genericptr_t)mtmp->m_id; 438. #ifdef DEBUG 439. if (find_mid((unsigned)ls->id, FM_EVERYWHERE) != mtmp) 440. panic("write_ls: can't find mon #%u!", (unsigned)ls->id); 441. #endif 442. } 443. ls->flags |= LSF_NEEDS_FIXUP; 444. bwrite(fd, (genericptr_t)ls, sizeof(light_source)); 445. ls->id = arg_save; 446. ls->flags &= ~LSF_NEEDS_FIXUP; 447. } 448. } else { 449. impossible("write_ls: bad type (%d)", ls->type); 450. } 451. } 452. 453. /* Change light source's ID from src to dest. */ 454. void 455. obj_move_light_source(src, dest) 456. struct obj *src, *dest; 457. { 458. light_source *ls; 459. 460. for (ls = light_base; ls; ls = ls->next) 461. if (ls->type == LS_OBJECT && ls->id == (genericptr_t) src) 462. ls->id = (genericptr_t) dest; 463. src->lamplit = 0; 464. dest->lamplit = 1; 465. } 466. 467. /* return true if there exist any light sources */ 468. boolean 469. any_light_source() 470. { 471. return light_base != (light_source *) 0; 472. } 473. 474. /* 475. * Snuff an object light source if at (x,y). This currently works 476. * only for burning light sources. 477. */ 478. void 479. snuff_light_source(x, y) 480. int x, y; 481. { 482. light_source *ls; 483. struct obj *obj; 484. 485. for (ls = light_base; ls; ls = ls->next) 486. /* 487. Is this position check valid??? Can I assume that the positions 488. will always be correct because the objects would have been 489. updated with the last vision update? [Is that recent enough???] 490. */ 491. if (ls->type == LS_OBJECT && ls->x == x && ls->y == y) { 492. obj = (struct obj *) ls->id; 493. if (obj_is_burning(obj)) { 494. /* The only way to snuff Sunsword is to unwield it. Darkness 495. * scrolls won't affect it. (If we got here because it was 496. * dropped or thrown inside a monster, this won't matter anyway 497. * because it will go out when dropped.) 498. */ 499. if (artifact_light(obj)) continue; 500. end_burn(obj, obj->otyp != MAGIC_LAMP); 501. /* 502. * The current ls element has just been removed (and 503. * ls->next is now invalid). Return assuming that there 504. * is only one light source attached to each object. 505. */ 506. return; 507. } 508. } 509. } 510. 511. /* Return TRUE if object sheds any light at all. */ 512. boolean 513. obj_sheds_light(obj) 514. struct obj *obj; 515. { 516. /* so far, only burning objects shed light */ 517. /* WAC - Some artifacts now shed light */ 518. 519. return (obj_is_burning(obj) || obj_permanent_light(obj)); 520. } 521. 522. /* Return TRUE if sheds light AND will be snuffed by end_burn(). */ 523. boolean 524. obj_is_burning(obj) 525. struct obj *obj; 526. { 527. return (obj->lamplit && 528. ( obj->otyp == MAGIC_LAMP 529. || obj->otyp == MAGIC_CANDLE 530. || ignitable(obj) 531. #ifdef LIGHTSABERS 532. || is_lightsaber(obj) 533. #endif 534. || artifact_light(obj))); 535. } 536. 537. /* WAC Return TRUE if object always lights up 538. * Currently only artifacts have this property 539. */ 540. boolean 541. obj_permanent_light(obj) 542. struct obj *obj; 543. { 544. return ((obj->lamplit) && 545. (artifact_light(obj))); 546. } 547. 548. /* copy the light source(s) attachted to src, and attach it/them to dest */ 549. void 550. obj_split_light_source(src, dest) 551. struct obj *src, *dest; 552. { 553. light_source *ls, *new_ls; 554. 555. for (ls = light_base; ls; ls = ls->next) 556. if (ls->type == LS_OBJECT && ls->id == (genericptr_t) src) { 557. /* 558. * Insert the new source at beginning of list. This will 559. * never interfere us walking down the list - we are already 560. * past the insertion point. 561. */ 562. new_ls = (light_source *) alloc(sizeof(light_source)); 563. *new_ls = *ls; 564. if (Is_candle(src)) { 565. /* split candles may emit less light than original group */ 566. ls->range = candle_light_range(src); 567. new_ls->range = candle_light_range(dest); 568. vision_full_recalc = 1; /* in case range changed */ 569. } 570. new_ls->id = (genericptr_t) dest; 571. new_ls->next = light_base; 572. light_base = new_ls; 573. dest->lamplit = 1; /* now an active light source */ 574. } 575. } 576. 577. /* light source `src' has been folded into light source `dest'; 578. used for merging lit candles and adding candle(s) to lit candelabrum */ 579. void 580. obj_merge_light_sources(src, dest) 581. struct obj *src, *dest; 582. { 583. light_source *ls; 584. 585. /* src == dest implies adding to candelabrum */ 586. if (src != dest) end_burn(src, TRUE); /* extinguish candles */ 587. 588. for (ls = light_base; ls; ls = ls->next) 589. if (ls->type == LS_OBJECT && ls->id == (genericptr_t) dest) { 590. ls->range = candle_light_range(dest); 591. vision_full_recalc = 1; /* in case range changed */ 592. break; 593. } 594. } 595. 596. /* Candlelight is proportional to the number of candles; 597. minimum range is 2 rather than 1 for playability. */ 598. int 599. candle_light_range(obj) 600. struct obj *obj; 601. { 602. int radius; 603. 604. if (obj->otyp == CANDELABRUM_OF_INVOCATION) { 605. /* 606. * The special candelabrum emits more light than the 607. * corresponding number of candles would. 608. * 1..3 candles, range 2 (minimum range); 609. * 4..6 candles, range 3 (normal lamp range); 610. * 7 candles, range 4 (bright). 611. */ 612. radius = (obj->spe < 4) ? 2 : (obj->spe < 7) ? 3 : 4; 613. } else if (Is_candle(obj)) { 614. /* 615. * Range is incremented by powers of 7 so that it will take 616. * wizard mode quantities of candles to get more light than 617. * from a lamp, without imposing an arbitrary limit. 618. * 1..6 candles, range 2; 619. * 7..48 candles, range 3; 620. * 49..342 candles, range 4; &c. 621. */ 622. long n = obj->quan; 623. 624. radius = 1; /* always incremented at least once */ 625. do { 626. radius++; 627. n /= 7L; 628. } while (n > 0L); 629. } else { 630. /* we're only called for lit candelabrum or candles */ 631. /* impossible("candlelight for %d?", obj->otyp); */ 632. radius = 3; /* lamp's value */ 633. } 634. return radius; 635. } 636. 637. #ifdef WIZARD 638. extern char *FDECL(fmt_ptr, (const genericptr, char *)); /* from alloc.c */ 639. 640. int 641. wiz_light_sources() 642. { 643. winid win; 644. char buf[BUFSZ], arg_address[20]; 645. light_source *ls; 646. 647. win = create_nhwindow(NHW_MENU); /* corner text window */ 648. if (win == WIN_ERR) return 0; 649. 650. Sprintf(buf, "Mobile light sources: hero @ (%2d,%2d)", u.ux, u.uy); 651. putstr(win, 0, buf); 652. putstr(win, 0, ""); 653. 654. if (light_base) { 655. putstr(win, 0, "location range flags type id"); 656. putstr(win, 0, "-------- ----- ------ ---- -------"); 657. for (ls = light_base; ls; ls = ls->next) { 658. Sprintf(buf, " %2d,%2d %2d 0x%04x %s %s", 659. ls->x, ls->y, ls->range, ls->flags, 660. (ls->type == LS_OBJECT ? "obj" : 661. ls->type == LS_MONSTER ? 662. (mon_is_local((struct monst *)ls->id) ? "mon" : 663. ((struct monst *)ls->id == &youmonst) ? "you" : 664. "<m>") : /* migrating monster */ 665. "???"), 666. fmt_ptr(ls->id, arg_address)); 667. putstr(win, 0, buf); 668. } 669. } else 670. putstr(win, 0, "<none>"); 671. 672. 673. display_nhwindow(win, FALSE); 674. destroy_nhwindow(win); 675. 676. return 0; 677. } 678. 679. #endif /* WIZARD */ 680. 681. #endif /* OVL3 */ 682. 683. /*light.c*/
