git.hungrycats.org Git - xscreensaver/blob - hacks/lightning.c

   1 /* -*- Mode: C; tab-width: 4 -*- */
   2 /* lightning --- fractal lightning bolds */
   3
   4 #if 0
   5 static const char sccsid[] = "@(#)lightning.c   5.00 2000/11/01 xlockmore";
   6 #endif
   7
   8 /*-
   9  * Copyright (c) 1996 by Keith Romberg <kromberg@saxe.com>
  10  *
  11  * Permission to use, copy, modify, and distribute this software and its
  12  * documentation for any purpose and without fee is hereby granted,
  13  * provided that the above copyright notice appear in all copies and that
  14  * both that copyright notice and this permission notice appear in
  15  * supporting documentation.
  16  *
  17  * This file is provided AS IS with no warranties of any kind.  The author
  18  * shall have no liability with respect to the infringement of copyrights,
  19  * trade secrets or any patents by this file or any part thereof.  In no
  20  * event will the author be liable for any lost revenue or profits or
  21  * other special, indirect and consequential damages.
  22  *
  23  * Revision History:
  24  * 01-Nov-2000: Allocation checks
  25  * 10-May-1997: Compatible with xscreensaver
  26  * 14-Jul-1996: Cleaned up code.
  27  * 27-Jun-1996: Written and submitted by Keith Romberg <kromberg@saxe.com>.
  28  */
  29
  30 #ifdef STANDALONE
  31 # define MODE_lightning
  32 # define DEFAULTS "*delay: 10000 \n" \
  33                   "*ncolors: 64  \n"
  34
  35 # define BRIGHT_COLORS
  36 # define reshape_lightning 0
  37 # define lightning_handle_event 0
  38 # include "xlockmore.h"         /* in xscreensaver distribution */
  39 #else /* STANDALONE */
  40 # include "xlock.h"             /* in xlockmore distribution */
  41 #endif /* STANDALONE */
  42
  43 #ifdef MODE_lightning
  44
  45 ENTRYPOINT ModeSpecOpt lightning_opts =
  46 {0, (XrmOptionDescRec *) NULL, 0, (argtype *) NULL, (OptionStruct *) NULL};
  47
  48 #ifdef USE_MODULES
  49 ModStruct   lightning_description =
  50 {"lightning", "init_lightning", "draw_lightning", "release_lightning",
  51  "refresh_lightning", "init_lightning", (char *) NULL, &lightning_opts,
  52  10000, 1, 1, 1, 64, 0.6, "",
  53  "Shows Keith's fractal lightning bolts", 0, NULL};
  54
  55 #endif
  56
  57 #define BOLT_NUMBER 4
  58 #define BOLT_ITERATION 4
  59 #define LONG_FORK_ITERATION 3
  60 #define MEDIUM_FORK_ITERATION 2
  61 #define SMALL_FORK_ITERATION 1
  62
  63 #define WIDTH_VARIATION 30
  64 #define HEIGHT_VARIATION 15
  65
  66 #define DELAY_TIME_AMOUNT 15
  67 #define MULTI_DELAY_TIME_BASE 5
  68
  69 #define MAX_WIGGLES 16
  70 #define WIGGLE_BASE 8
  71 #define WIGGLE_AMOUNT 14
  72
  73 #define RANDOM_FORK_PROBILITY   4
  74
  75 #define FIRST_LEVEL_STRIKE 0
  76 #define LEVEL_ONE_STRIKE 1
  77 #define LEVEL_TWO_STRIKE 2
  78
  79 #define BOLT_VERTICIES ((1<<BOLT_ITERATION)-1)
  80   /* BOLT_ITERATION = 4. 2^(BOLT_ITERATION) - 1 = 15 */
  81
  82 #define NUMBER_FORK_VERTICIES 9
  83
  84 #define FLASH_PROBILITY 20
  85 #define MAX_FLASH_AMOUNT 2      /*  half the total duration of the bolt  */
  86
  87 typedef struct {
  88         XPoint      ForkVerticies[NUMBER_FORK_VERTICIES];
  89         int         num_used;
  90 } Fork;
  91
  92 typedef struct {
  93         XPoint      end1, end2;
  94         XPoint      middle[BOLT_VERTICIES];
  95         int         fork_number;
  96         int         forks_start[2];
  97         Fork        branch[2];
  98         int         wiggle_number;
  99         int         wiggle_amount;
 100         int         delay_time;
 101         int         flash;
 102         int         flash_begin, flash_stop;
 103         int         visible;
 104         int         strike_level;
 105 } Lightning;
 106
 107 typedef struct {
 108         Lightning   bolts[BOLT_NUMBER];
 109         int         scr_width, scr_height;
 110         int         multi_strike;
 111         int         give_it_hell;
 112         int         draw_time;
 113         int         stage;
 114         int         busyLoop;
 115         unsigned long color;
 116 } Storm;
 117
 118 static Storm *Helga = (Storm *) NULL;
 119
 120 /*-------------------   function prototypes  ----------------------------*/
 121
 122 static int  distance(XPoint a, XPoint b);
 123
 124 static int  setup_multi_strike(void);
 125 static int  flashing_strike(void);
 126 static void flash_duration(int *start, int *end, int total_duration);
 127 static void random_storm(Storm * st);
 128 static void generate(XPoint A, XPoint B, int iter, XPoint * verts, int *vert_index);
 129 static void create_fork(Fork * f, XPoint start, XPoint end, int level);
 130
 131 static void first_strike(Lightning bolt, ModeInfo * mi);
 132 static void draw_bolt(Lightning * bolt, ModeInfo * mi);
 133 static void draw_line(ModeInfo * mi, XPoint * p, int number, GC use, int x_offset);
 134 static void level1_strike(Lightning bolt, ModeInfo * mi);
 135 static void level2_strike(Lightning bolt, ModeInfo * mi);
 136
 137 static int  storm_active(Storm * st);
 138 static void update_bolt(Lightning * bolt, int time_now);
 139 static void wiggle_bolt(Lightning * bolt);
 140 static void wiggle_line(XPoint * p, int number, int wiggle_amount);
 141
 142 /*-------------------------  functions  ---------------------------------*/
 143
 144 static int
 145 setup_multi_strike(void)
 146 {
 147         int         result, multi_prob;
 148
 149         multi_prob = NRAND(100);
 150
 151         if (multi_prob < 50)
 152                 result = 1;
 153         else if ((multi_prob >= 51) && (multi_prob < 75))
 154                 result = 2;
 155         else if ((multi_prob >= 76) && (multi_prob < 92))
 156                 result = 3;
 157         else
 158                 result = BOLT_NUMBER;   /* 4 */
 159
 160         return (result);
 161 }
 162
 163 /*-------------------------------------------------------------------------*/
 164
 165 static int
 166 flashing_strike(void)
 167 {
 168         int         tmp = NRAND(FLASH_PROBILITY);
 169
 170         if (tmp <= FLASH_PROBILITY)
 171                 return (1);
 172         return (0);
 173 }
 174
 175 /*-------------------------------------------------------------------------*/
 176
 177 static void
 178 flash_duration(int *start, int *end, int total_duration)
 179 {
 180         int         mid, d;
 181
 182         mid = total_duration / MAX_FLASH_AMOUNT;
 183         d = NRAND(total_duration / MAX_FLASH_AMOUNT) / 2;
 184         *start = mid - d;
 185         *end = mid + d;
 186 }
 187
 188 /*-------------------------------------------------------------------------*/
 189
 190 static void
 191 random_storm(Storm * st)
 192 {
 193         int         i, j, tmp;
 194         XPoint      p;
 195
 196         for (i = 0; i < st->multi_strike; i++) {
 197                 st->bolts[i].end1.x = NRAND(st->scr_width);
 198                 st->bolts[i].end1.y = 0;
 199                 st->bolts[i].end2.x = NRAND(st->scr_width);
 200                 st->bolts[i].end2.y = st->scr_height;
 201                 st->bolts[i].wiggle_number = WIGGLE_BASE + NRAND(MAX_WIGGLES);
 202                 if ((st->bolts[i].flash = flashing_strike()))
 203                         flash_duration(&(st->bolts[i].flash_begin), &(st->bolts[i].flash_stop),
 204                                        st->bolts[i].wiggle_number);
 205                 else
 206                         st->bolts[i].flash_begin = st->bolts[i].flash_stop = 0;
 207                 st->bolts[i].wiggle_amount = WIGGLE_AMOUNT;
 208                 if (i == 0)
 209                         st->bolts[i].delay_time = NRAND(DELAY_TIME_AMOUNT);
 210                 else
 211                         st->bolts[i].delay_time = NRAND(DELAY_TIME_AMOUNT) +
 212                                 (MULTI_DELAY_TIME_BASE * i);
 213                 st->bolts[i].strike_level = FIRST_LEVEL_STRIKE;
 214                 tmp = 0;
 215                 generate(st->bolts[i].end1, st->bolts[i].end2, BOLT_ITERATION,
 216                          st->bolts[i].middle, &tmp);
 217                 st->bolts[i].fork_number = 0;
 218                 st->bolts[i].visible = 0;
 219                 for (j = 0; j < BOLT_VERTICIES; j++) {
 220                         if (st->bolts[i].fork_number >= 2)
 221                                 break;
 222                         if (NRAND(100) < RANDOM_FORK_PROBILITY) {
 223                                 p.x = NRAND(st->scr_width);
 224                                 p.y = st->scr_height;
 225                                 st->bolts[i].forks_start[st->bolts[i].fork_number] = j;
 226                                 create_fork(&(st->bolts[i].branch[st->bolts[i].fork_number]),
 227                                             st->bolts[i].middle[j], p, j);
 228                                 st->bolts[i].fork_number++;
 229                         }
 230                 }
 231         }
 232 }
 233
 234 static void
 235 generate(XPoint A, XPoint B, int iter, XPoint * verts, int *vert_index)
 236 {
 237         XPoint      mid;
 238
 239         mid.x = (A.x + B.x) / 2 + NRAND(WIDTH_VARIATION) - WIDTH_VARIATION / 2;
 240         mid.y = (A.y + B.y) / 2 + NRAND(HEIGHT_VARIATION) - HEIGHT_VARIATION / 2;
 241
 242         if (!iter) {
 243                 verts[*vert_index].x = mid.x;
 244                 verts[*vert_index].y = mid.y;
 245                 (*vert_index)++;
 246                 return;
 247         }
 248         generate(A, mid, iter - 1, verts, vert_index);
 249         generate(mid, B, iter - 1, verts, vert_index);
 250 }
 251
 252 /*------------------------------------------------------------------------*/
 253
 254 static void
 255 create_fork(Fork * f, XPoint start, XPoint end, int level)
 256 {
 257         int         tmp = 1;
 258
 259         f->ForkVerticies[0].x = start.x;
 260         f->ForkVerticies[0].y = start.y;
 261
 262         if (level <= 6) {
 263                 generate(start, end, LONG_FORK_ITERATION, f->ForkVerticies, &tmp);
 264                 f->num_used = 9;
 265         } else if ((level > 6) && (level <= 11)) {
 266                 generate(start, end, MEDIUM_FORK_ITERATION, f->ForkVerticies, &tmp);
 267                 f->num_used = 5;
 268         } else {
 269                 if (distance(start, end) > 100) {
 270                         generate(start, end, MEDIUM_FORK_ITERATION, f->ForkVerticies, &tmp);
 271                         f->num_used = 5;
 272                 } else {
 273                         generate(start, end, SMALL_FORK_ITERATION, f->ForkVerticies, &tmp);
 274                         f->num_used = 3;
 275                 }
 276         }
 277
 278         f->ForkVerticies[f->num_used - 1].x = end.x;
 279         f->ForkVerticies[f->num_used - 1].y = end.y;
 280 }
 281
 282 /*------------------------------------------------------------------------*/
 283
 284 static void
 285 update_bolt(Lightning * bolt, int time_now)
 286 {
 287         wiggle_bolt(bolt);
 288         if ((bolt->wiggle_amount == 0) && (bolt->wiggle_number > 2))
 289                 bolt->wiggle_number = 0;
 290         if (((time_now % 3) == 0))
 291                 bolt->wiggle_amount++;
 292
 293         if (((time_now >= bolt->delay_time) && (time_now < bolt->flash_begin)) ||
 294             (time_now > bolt->flash_stop))
 295                 bolt->visible = 1;
 296         else
 297                 bolt->visible = 0;
 298
 299         if (time_now == bolt->delay_time)
 300                 bolt->strike_level = FIRST_LEVEL_STRIKE;
 301         else if (time_now == (bolt->delay_time + 1))
 302                 bolt->strike_level = LEVEL_ONE_STRIKE;
 303         else if ((time_now > (bolt->delay_time + 1)) &&
 304                  (time_now <= (bolt->delay_time + bolt->flash_begin - 2)))
 305                 bolt->strike_level = LEVEL_TWO_STRIKE;
 306         else if (time_now == (bolt->delay_time + bolt->flash_begin - 1))
 307                 bolt->strike_level = LEVEL_ONE_STRIKE;
 308         else if (time_now == (bolt->delay_time + bolt->flash_stop + 1))
 309                 bolt->strike_level = LEVEL_ONE_STRIKE;
 310         else
 311                 bolt->strike_level = LEVEL_TWO_STRIKE;
 312 }
 313
 314 /*------------------------------------------------------------------------*/
 315
 316 static void
 317 draw_bolt(Lightning * bolt, ModeInfo * mi)
 318 {
 319         if (bolt->visible) {
 320                 if (bolt->strike_level == FIRST_LEVEL_STRIKE)
 321                         first_strike(*bolt, mi);
 322                 else if (bolt->strike_level == LEVEL_ONE_STRIKE)
 323                         level1_strike(*bolt, mi);
 324                 else
 325                         level2_strike(*bolt, mi);
 326         }
 327 }
 328
 329 /*------------------------------------------------------------------------*/
 330
 331 static void
 332 first_strike(Lightning bolt, ModeInfo * mi)
 333 {
 334         Display    *display = MI_DISPLAY(mi);
 335         Window      window = MI_WINDOW(mi);
 336         GC          gc = MI_GC(mi);
 337         int         i;
 338
 339         XSetForeground(display, gc, MI_WHITE_PIXEL(mi));
 340         XDrawLine(display, window, gc,
 341                bolt.end1.x, bolt.end1.y, bolt.middle[0].x, bolt.middle[0].y);
 342         draw_line(mi, bolt.middle, BOLT_VERTICIES, gc, 0);
 343         XDrawLine(display, window, gc,
 344         bolt.middle[BOLT_VERTICIES - 1].x, bolt.middle[BOLT_VERTICIES - 1].y,
 345                   bolt.end2.x, bolt.end2.y);
 346
 347         for (i = 0; i < bolt.fork_number; i++)
 348                 draw_line(mi, bolt.branch[i].ForkVerticies, bolt.branch[i].num_used,
 349                           gc, 0);
 350 }
 351
 352 /*------------------------------------------------------------------------*/
 353
 354 static void
 355 draw_line(ModeInfo * mi, XPoint * points, int number, GC to_use, int offset)
 356 {
 357         int         i;
 358
 359         for (i = 0; i < number - 1; i++) {
 360                 if (points[i].y <= points[i + 1].y)
 361                         XDrawLine(MI_DISPLAY(mi), MI_WINDOW(mi), to_use, points[i].x + offset,
 362                                   points[i].y, points[i + 1].x + offset, points[i + 1].y);
 363                 else {
 364                         if (points[i].x < points[i + 1].x)
 365                                 XDrawLine(MI_DISPLAY(mi), MI_WINDOW(mi), to_use, points[i].x +
 366                                           offset, points[i].y + offset, points[i + 1].x + offset,
 367                                           points[i + 1].y + offset);
 368                         else
 369                                 XDrawLine(MI_DISPLAY(mi), MI_WINDOW(mi), to_use, points[i].x -
 370                                           offset, points[i].y + offset, points[i + 1].x - offset,
 371                                           points[i + 1].y + offset);
 372                 }
 373         }
 374 }
 375
 376 /*------------------------------------------------------------------------*/
 377
 378 static void
 379 level1_strike(Lightning bolt, ModeInfo * mi)
 380 {
 381         Display    *display = MI_DISPLAY(mi);
 382         Window      window = MI_WINDOW(mi);
 383         Storm      *st = &Helga[MI_SCREEN(mi)];
 384         GC          gc = MI_GC(mi);
 385         int         i;
 386
 387         if (MI_NPIXELS(mi) > 2) /* color */
 388                 XSetForeground(display, gc, MI_PIXEL(mi, st->color));
 389         else
 390                 XSetForeground(display, gc, MI_WHITE_PIXEL(mi));
 391         XDrawLine(display, window, gc,
 392         bolt.end1.x - 1, bolt.end1.y, bolt.middle[0].x - 1, bolt.middle[0].y);
 393         draw_line(mi, bolt.middle, BOLT_VERTICIES, gc, -1);
 394         XDrawLine(display, window, gc,
 395                   bolt.middle[BOLT_VERTICIES - 1].x - 1,
 396             bolt.middle[BOLT_VERTICIES - 1].y, bolt.end2.x - 1, bolt.end2.y);
 397         XDrawLine(display, window, gc,
 398         bolt.end1.x + 1, bolt.end1.y, bolt.middle[0].x + 1, bolt.middle[0].y);
 399         draw_line(mi, bolt.middle, BOLT_VERTICIES, gc, 1);
 400         XDrawLine(display, window, gc,
 401                   bolt.middle[BOLT_VERTICIES - 1].x + 1,
 402             bolt.middle[BOLT_VERTICIES - 1].y, bolt.end2.x + 1, bolt.end2.y);
 403
 404         for (i = 0; i < bolt.fork_number; i++) {
 405                 draw_line(mi, bolt.branch[i].ForkVerticies, bolt.branch[i].num_used,
 406                           gc, -1);
 407                 draw_line(mi, bolt.branch[i].ForkVerticies, bolt.branch[i].num_used,
 408                           gc, 1);
 409         }
 410         first_strike(bolt, mi);
 411 }
 412
 413 /*------------------------------------------------------------------------*/
 414
 415 static int
 416 distance(XPoint a, XPoint b)
 417 {
 418         return ((int) sqrt((double) (a.x - b.x) * (a.x - b.x) + (a.y - b.y) * (a.y - b.y)));
 419 }
 420
 421 /*------------------------------------------------------------------------*/
 422
 423 static void
 424 level2_strike(Lightning bolt, ModeInfo * mi)
 425 {
 426         Display    *display = MI_DISPLAY(mi);
 427         Window      window = MI_WINDOW(mi);
 428         Storm      *st = &Helga[MI_SCREEN(mi)];
 429         GC          gc = MI_GC(mi);
 430         int         i;
 431
 432         /* This was originally designed to be a little darker then the
 433            level1 strike.  This was changed to get it to work on
 434            multiscreens and to add more color variety.   I tried
 435            stippling but it did not look good. */
 436         if (MI_NPIXELS(mi) > 2)
 437                 XSetForeground(display, gc, MI_PIXEL(mi, st->color));
 438         else
 439                 XSetForeground(display, gc, MI_WHITE_PIXEL(mi));
 440         XDrawLine(display, window, gc,
 441         bolt.end1.x - 2, bolt.end1.y, bolt.middle[0].x - 2, bolt.middle[0].y);
 442         draw_line(mi, bolt.middle, BOLT_VERTICIES, gc, -2);
 443         XDrawLine(display, window, gc,
 444                   bolt.middle[BOLT_VERTICIES - 1].x - 2,
 445             bolt.middle[BOLT_VERTICIES - 1].y, bolt.end2.x - 2, bolt.end2.y);
 446
 447         XDrawLine(display, window, gc,
 448         bolt.end1.x + 2, bolt.end1.y, bolt.middle[0].x + 2, bolt.middle[0].y);
 449         draw_line(mi, bolt.middle, BOLT_VERTICIES, gc, 2);
 450         XDrawLine(display, window, gc,
 451                   bolt.middle[BOLT_VERTICIES - 1].x + 2,
 452             bolt.middle[BOLT_VERTICIES - 1].y, bolt.end2.x + 2, bolt.end2.y);
 453
 454         for (i = 0; i < bolt.fork_number; i++) {
 455                 draw_line(mi, bolt.branch[i].ForkVerticies, bolt.branch[i].num_used,
 456                           gc, -2);
 457                 draw_line(mi, bolt.branch[i].ForkVerticies, bolt.branch[i].num_used,
 458                           gc, 2);
 459         }
 460         level1_strike(bolt, mi);
 461 }
 462
 463 /*------------------------------------------------------------------------*/
 464
 465 static int
 466 storm_active(Storm * st)
 467 {
 468         int         i, atleast_1 = 0;
 469
 470         for (i = 0; i < st->multi_strike; i++)
 471                 if (st->bolts[i].wiggle_number > 0)
 472                         atleast_1++;
 473
 474         return (atleast_1);
 475 }
 476
 477 /*------------------------------------------------------------------------*/
 478
 479 static void
 480 wiggle_bolt(Lightning * bolt)
 481 {
 482         int         i;
 483
 484         wiggle_line(bolt->middle, BOLT_VERTICIES, bolt->wiggle_amount);
 485         bolt->end2.x += NRAND(bolt->wiggle_amount) - bolt->wiggle_amount / 2;
 486         bolt->end2.y += NRAND(bolt->wiggle_amount) - bolt->wiggle_amount / 2;
 487
 488         for (i = 0; i < bolt->fork_number; i++) {
 489                 wiggle_line(bolt->branch[i].ForkVerticies, bolt->branch[i].num_used,
 490                             bolt->wiggle_amount);
 491                 bolt->branch[i].ForkVerticies[0].x = bolt->middle[bolt->forks_start[i]].x;
 492                 bolt->branch[i].ForkVerticies[0].y = bolt->middle[bolt->forks_start[i]].y;
 493         }
 494
 495         if (bolt->wiggle_amount > 1)
 496                 bolt->wiggle_amount -= 1;
 497         else
 498                 bolt->wiggle_amount = 0;
 499 }
 500
 501 /*------------------------------------------------------------------------*/
 502
 503 static void
 504 wiggle_line(XPoint * p, int number, int amount)
 505 {
 506         int         i;
 507
 508         for (i = 0; i < number; i++) {
 509                 p[i].x += NRAND(amount) - amount / 2;
 510                 p[i].y += NRAND(amount) - amount / 2;
 511         }
 512 }
 513
 514 /*------------------------------------------------------------------------*/
 515
 516 ENTRYPOINT void
 517 init_lightning (ModeInfo * mi)
 518 {
 519         Storm      *st;
 520
 521         MI_INIT (mi, Helga, 0);
 522         st = &Helga[MI_SCREEN(mi)];
 523
 524         st->scr_width = MI_WIDTH(mi);
 525         st->scr_height = MI_HEIGHT(mi);
 526
 527         st->multi_strike = setup_multi_strike();
 528         random_storm(st);
 529         st->stage = 0;
 530 }
 531
 532 /*------------------------------------------------------------------------*/
 533
 534 ENTRYPOINT void
 535 draw_lightning (ModeInfo * mi)
 536 {
 537         int         i;
 538         Storm      *st;
 539
 540         if (Helga == NULL)
 541                 return;
 542         st = &Helga[MI_SCREEN(mi)];
 543         MI_IS_DRAWN(mi) = True;
 544         switch (st->stage) {
 545                 case 0:
 546                         MI_IS_DRAWN(mi) = False;
 547                         MI_CLEARWINDOW(mi);
 548                         MI_IS_DRAWN(mi) = True;
 549
 550                         st->color = NRAND(MI_NPIXELS(mi));
 551                         st->draw_time = 0;
 552                         if (storm_active(st))
 553                                 st->stage++;
 554                         else
 555                                 st->stage = 4;
 556                         break;
 557                 case 1:
 558                         for (i = 0; i < st->multi_strike; i++) {
 559                                 if (st->bolts[i].visible)
 560                                         draw_bolt(&(st->bolts[i]), mi);
 561                                 update_bolt(&(st->bolts[i]), st->draw_time);
 562                         }
 563                         st->draw_time++;
 564                         st->stage++;
 565                         st->busyLoop = 0;
 566                         break;
 567                 case 2:
 568                         if (++st->busyLoop > 6) {
 569                                 st->stage++;
 570                                 st->busyLoop = 0;
 571                         }
 572                         break;
 573                 case 3:
 574                         MI_IS_DRAWN(mi) = False;
 575                         MI_CLEARWINDOW(mi);
 576                         MI_IS_DRAWN(mi) = True;
 577
 578                         if (storm_active(st))
 579                                 st->stage = 1;
 580                         else
 581                                 st->stage++;
 582                         break;
 583                 case 4:
 584                         if (++st->busyLoop > 100) {
 585                                 st->busyLoop = 0;
 586                         }
 587                         init_lightning(mi);
 588                         break;
 589         }
 590 }
 591
 592 ENTRYPOINT void
 593 release_lightning(ModeInfo * mi)
 594 {
 595         if (Helga != NULL) {
 596                 (void) free((void *) Helga);
 597                 Helga = (Storm *) NULL;
 598         }
 599 }
 600
 601 ENTRYPOINT void
 602 refresh_lightning(ModeInfo * mi)
 603 {
 604         /* Do nothing, it will refresh by itself */
 605 }
 606
 607 XSCREENSAVER_MODULE ("Lightning", lightning)
 608
 609
 610 #endif /* MODE_lightning */