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

   1 /* -*- mode: C; tab-width: 4 -*-
   2  * xscreensaver, Copyright (c) 1992-2014 Jamie Zawinski <jwz@jwz.org>
   3  *
   4  * Permission to use, copy, modify, distribute, and sell this software and its
   5  * documentation for any purpose is hereby granted without fee, provided that
   6  * the above copyright notice appear in all copies and that both that
   7  * copyright notice and this permission notice appear in supporting
   8  * documentation.  No representations are made about the suitability of this
   9  * software for any purpose.  It is provided "as is" without express or
  10  * implied warranty.
  11  */
  12
  13 /* distort
  14  * by Jonas Munsin (jmunsin@iki.fi) and Jamie Zawinski <jwz@jwz.org>
  15  * TODO:
  16  *      -check the allocations in init_round_lense again, maybe make it possible again
  17  *       to use swamp without pre-allocating/calculating (although that
  18  *       makes it slower) - -swamp is memory hungry
  19  *      -more distortion matrices (fortunately, I'm out of ideas :)
  20  * Stuff that would be cool but probably too much of a resource hog:
  21  *      -some kind of interpolation to avoid jaggies
  22  *    -large speed values leaves the image distorted
  23  * program idea borrowed from a screensaver on a non-*NIX OS,
  24  *
  25  * 28 Sep 1999 Jonas Munsin (jmunsin@iki.fi)
  26  *    Added about 10x faster algortim for 8, 16 and 32 bpp (modifies pixels
  27  *    directly avoiding costly XPutPixle(XGetPixel()) calls, inspired by
  28  *    xwhirl made by horvai@clipper.ens.fr (Peter Horvai) and the XFree86
  29  *    Xlib sources.
  30  *    This piece of code is really horrible, but it works, and at the moment
  31  *    I don't have time or inspiration to fix something that works (knock
  32  *    on wood).
  33  * 08 Oct 1999 Jonas Munsin (jmunsin@iki.fi)
  34  *      Corrected several bugs causing references beyond allocated memory.
  35  * 09 Oct 2016 Dave Odell (dmo2118@gmail.com)
  36  *  Updated for new xshm.c.
  37  */
  38
  39 #include <math.h>
  40 #include <time.h>
  41 #include "screenhack.h"
  42 /*#include <X11/Xmd.h>*/
  43 # include "xshm.h"
  44
  45 #define CARD32 unsigned int
  46 #define CARD16 unsigned short
  47 #define CARD8  unsigned char
  48
  49
  50 struct coo {
  51         int x;
  52         int y;
  53         int r, r_change;
  54         int xmove, ymove;
  55 };
  56
  57 struct state {
  58   Display *dpy;
  59   Window window;
  60
  61   struct coo xy_coo[10];
  62
  63   int delay, radius, speed, number, blackhole, vortex, magnify, reflect, slow;
  64   int duration;
  65   time_t start_time;
  66
  67   XWindowAttributes xgwa;
  68   GC gc;
  69   unsigned long black_pixel;
  70
  71   XImage *orig_map, *buffer_map;
  72   unsigned long *buffer_map_cache;
  73
  74   int ***from;
  75   int ****from_array;
  76   int *fast_from;
  77
  78   int bpp_size;
  79
  80   XShmSegmentInfo shm_info;
  81
  82   void (*effect) (struct state *, int);
  83   void (*draw) (struct state *, int);
  84   void (*draw_routine) (struct state *st, XImage *, XImage *, int, int, int *);
  85
  86   async_load_state *img_loader;
  87   Pixmap pm;
  88 };
  89
  90
  91 static void move_lense(struct state *, int);
  92 static void swamp_thing(struct state *, int);
  93 static void new_rnd_coo(struct state *, int);
  94 static void init_round_lense(struct state *st);
  95 static void reflect_draw(struct state *, int);
  96 static void plain_draw(struct state *, int);
  97
  98 static void fast_draw_8 (struct state *st, XImage *, XImage *, int, int, int *);
  99 static void fast_draw_16(struct state *st, XImage *, XImage *, int, int, int *);
 100 static void fast_draw_32(struct state *st, XImage *, XImage *, int, int, int *);
 101 static void generic_draw(struct state *st, XImage *, XImage *, int, int, int *);
 102
 103
 104 static void distort_finish_loading (struct state *);
 105
 106 static void
 107 distort_reset (struct state *st)
 108 {
 109     char *s;
 110     int i;
 111
 112     st->start_time = 0;
 113
 114         XGetWindowAttributes (st->dpy, st->window, &st->xgwa);
 115
 116         st->delay = get_integer_resource(st->dpy, "delay", "Integer");
 117     st->duration = get_integer_resource (st->dpy, "duration", "Seconds");
 118         st->radius = get_integer_resource(st->dpy, "radius", "Integer");
 119         st->speed = get_integer_resource(st->dpy, "speed", "Integer");
 120         st->number = get_integer_resource(st->dpy, "number", "Integer");
 121
 122         st->blackhole = get_boolean_resource(st->dpy, "blackhole", "Boolean");
 123         st->vortex = get_boolean_resource(st->dpy, "vortex", "Boolean");
 124         st->magnify = get_boolean_resource(st->dpy, "magnify", "Boolean");
 125         st->reflect = get_boolean_resource(st->dpy, "reflect", "Boolean");
 126         st->slow = get_boolean_resource(st->dpy, "slow", "Boolean");
 127
 128     if (st->delay < 0) st->delay = 0;
 129     if (st->duration < 1) st->duration = 1;
 130
 131     st->effect = NULL;
 132     s = get_string_resource(st->dpy, "effect", "String");
 133         if (s && !strcasecmp(s,"swamp"))
 134       st->effect = &swamp_thing;
 135     else if (s && !strcasecmp(s,"bounce"))
 136       st->effect = &move_lense;
 137     else if (s && !strcasecmp(s,"none"))
 138       ;
 139     else if (s && *s)
 140       fprintf(stderr,"%s: bogus effect: %s\n", progname, s);
 141
 142         if (st->effect == NULL && st->radius == 0 && st->speed == 0 && st->number == 0
 143                 && !st->blackhole && !st->vortex && !st->magnify && !st->reflect) {
 144 /* if no cmdline options are given, randomly choose one of:
 145  * -radius 125 -number 4 -speed 1 -bounce
 146  * -radius 125 -number 4 -speed 1 -blackhole
 147  * -radius 125 -number 4 -speed 1 -vortex
 148  * -radius 125 -number 4 -speed 1 -vortex -magnify
 149  * -radius 125 -number 4 -speed 1 -vortex -magnify -blackhole
 150  * -radius 250 -number 1 -speed 2 -bounce
 151  * -radius 250 -number 1 -speed 2 -blackhole
 152  * -radius 250 -number 1 -speed 2 -vortex
 153  * -radius 250 -number 1 -speed 2 -vortex -magnify
 154  * -radius 250 -number 1 -speed 2 -vortex -magnify -blackhole
 155  * -radius 80 -number 1 -speed 2 -reflect
 156  * -radius 125 -number 3 -speed 2 -reflect
 157  * jwz: not these
 158  *   -radius 125 -number 4 -speed 2 -swamp
 159  *   -radius 125 -number 4 -speed 2 -swamp -blackhole
 160  *   -radius 125 -number 4 -speed 2 -swamp -vortex
 161  *   -radius 125 -number 4 -speed 2 -swamp -vortex -magnify
 162  *   -radius 125 -number 4 -speed 2 -swamp -vortex -magnify -blackhole
 163  */
 164
 165                 i = (random() % 12 /* 17 */);
 166
 167                 st->draw = &plain_draw;
 168
 169                 switch (i) {
 170                         case 0:
 171                                 st->radius=125;st->number=4;st->speed=1;
 172                                 st->effect=&move_lense;break;
 173                         case 1:
 174                                 st->radius=125;st->number=4;st->speed=1;st->blackhole=1;
 175                                 st->effect=&move_lense;break;
 176                         case 2:
 177                                 st->radius=125;st->number=4;st->speed=1;st->vortex=1;
 178                                 st->effect=&move_lense;break;
 179                         case 3:
 180                                 st->radius=125;st->number=4;st->speed=1;st->vortex=1;st->magnify=1;
 181                                 st->effect=&move_lense;break;
 182                         case 4:
 183                                 st->radius=125;st->number=4;st->speed=1;st->vortex=1;st->magnify=1;st->blackhole=1;
 184                                 st->effect=&move_lense;break;
 185                         case 5:
 186                                 st->radius=250;st->number=1;st->speed=2;
 187                                 st->effect=&move_lense;break;
 188                         case 6:
 189                                 st->radius=250;st->number=1;st->speed=2;st->blackhole=1;
 190                                 st->effect=&move_lense;break;
 191                         case 7:
 192                                 st->radius=250;st->number=1;st->speed=2;st->vortex=1;
 193                                 st->effect=&move_lense;break;
 194                         case 8:
 195                                 st->radius=250;st->number=1;st->speed=2;st->vortex=1;st->magnify=1;
 196                                 st->effect=&move_lense;break;
 197                         case 9:
 198                                 st->radius=250;st->number=1;st->speed=2;st->vortex=1;st->magnify=1;st->blackhole=1;
 199                                 st->effect=&move_lense;break;
 200
 201                         case 10:
 202                                 st->radius=80;st->number=1;st->speed=2;st->reflect=1;
 203                                 st->draw = &reflect_draw;st->effect = &move_lense;break;
 204                         case 11:
 205                                 st->radius=125;st->number=4;st->speed=2;st->reflect=1;
 206                                 st->draw = &reflect_draw;st->effect = &move_lense;break;
 207
 208 #if 0 /* jwz: not these */
 209                         case 12:
 210                                 st->radius=125;st->number=4;st->speed=2;
 211                                 effect=&swamp_thing;break;
 212                         case 13:
 213                                 st->radius=125;st->number=4;st->speed=2;st->blackhole=1;
 214                                 effect=&swamp_thing;break;
 215                         case 14:
 216                                 st->radius=125;st->number=4;st->speed=2;st->vortex=1;
 217                                 effect=&swamp_thing;break;
 218                         case 15:
 219                                 st->radius=125;st->number=4;st->speed=2;st->vortex=1;st->magnify=1;
 220                                 effect=&swamp_thing;break;
 221                         case 16:
 222                                 st->radius=125;st->number=4;st->speed=2;st->vortex=1;st->magnify=1;st->blackhole=1;
 223                                 effect=&swamp_thing;break;
 224 #endif
 225
 226             default:
 227                 abort(); break;
 228                 }
 229         }
 230
 231     /* never allow the radius to be too close to the min window dimension
 232      */
 233     if (st->radius > st->xgwa.width  * 0.3) st->radius = st->xgwa.width  * 0.3;
 234     if (st->radius > st->xgwa.height * 0.3) st->radius = st->xgwa.height * 0.3;
 235
 236
 237     /* -swamp mode consumes vast amounts of memory, proportional to radius --
 238        so throttle radius to a small-ish value (60 => ~30MB.)
 239      */
 240     if (st->effect == &swamp_thing && st->radius > 60)
 241       st->radius = 60;
 242
 243         if (st->delay < 0)
 244                 st->delay = 0;
 245         if (st->radius <= 0)
 246                 st->radius = 60;
 247         if (st->speed <= 0)
 248                 st->speed = 2;
 249         if (st->number <= 0)
 250                 st->number=1;
 251         if (st->number >= 10)
 252                 st->number=1;
 253         if (st->effect == NULL)
 254                 st->effect = &move_lense;
 255         if (st->reflect) {
 256                 st->draw = &reflect_draw;
 257                 st->effect = &move_lense;
 258         }
 259         if (st->draw == NULL)
 260                 st->draw = &plain_draw;
 261 }
 262
 263 static void *
 264 distort_init (Display *dpy, Window window)
 265 {
 266   struct state *st = (struct state *) calloc (1, sizeof(*st));
 267         XGCValues gcv;
 268         long gcflags;
 269
 270     st->dpy = dpy;
 271     st->window = window;
 272
 273     distort_reset (st);
 274
 275         st->black_pixel = BlackPixelOfScreen( st->xgwa.screen );
 276
 277         gcv.function = GXcopy;
 278         gcv.subwindow_mode = IncludeInferiors;
 279         gcflags = GCFunction;
 280         if (use_subwindow_mode_p(st->xgwa.screen, st->window)) /* see grabscreen.c */
 281                 gcflags |= GCSubwindowMode;
 282         st->gc = XCreateGC (st->dpy, st->window, gcflags, &gcv);
 283
 284     /* On MacOS X11, XGetImage on a Window often gets an inexplicable BadMatch,
 285        possibly due to the window manager having occluded something?  It seems
 286        nondeterministic. Loading the image into a pixmap instead fixes it. */
 287     if (st->pm) XFreePixmap (st->dpy, st->pm);
 288     st->pm = XCreatePixmap (st->dpy, st->window,
 289                             st->xgwa.width, st->xgwa.height, st->xgwa.depth);
 290
 291     st->img_loader = load_image_async_simple (0, st->xgwa.screen, st->window,
 292                                               st->pm, 0, 0);
 293     st->start_time = time ((time_t *) 0);
 294     return st;
 295 }
 296
 297 static void
 298 distort_finish_loading (struct state *st)
 299 {
 300     int i;
 301
 302     st->start_time = time ((time_t *) 0);
 303
 304     if (! st->pm) abort();
 305     XClearWindow (st->dpy, st->window);
 306     XCopyArea (st->dpy, st->pm, st->window, st->gc,
 307                0, 0, st->xgwa.width, st->xgwa.height, 0, 0);
 308         st->orig_map = XGetImage(st->dpy, st->pm, 0, 0,
 309                              st->xgwa.width, st->xgwa.height,
 310                              ~0L, ZPixmap);
 311         st->buffer_map_cache = malloc(sizeof(unsigned long)*(2*st->radius+st->speed+2)*(2*st->radius+st->speed+2));
 312
 313         if (st->buffer_map_cache == NULL) {
 314                 perror("distort");
 315                 exit(EXIT_FAILURE);
 316         }
 317
 318         st->buffer_map = create_xshm_image(st->dpy, st->xgwa.visual, st->orig_map->depth,
 319                                            ZPixmap, &st->shm_info,
 320                                            2*st->radius + st->speed + 2,
 321                                            2*st->radius + st->speed + 2);
 322
 323         if ((st->buffer_map->byte_order == st->orig_map->byte_order)
 324                         && (st->buffer_map->depth == st->orig_map->depth)
 325                         && (st->buffer_map->format == ZPixmap)
 326                         && (st->orig_map->format == ZPixmap)
 327                         && !st->slow) {
 328                 switch (st->orig_map->bits_per_pixel) {
 329                         case 32:
 330                                 st->draw_routine = &fast_draw_32;
 331                                 st->bpp_size = sizeof(CARD32);
 332                                 break;
 333                         case 16:
 334                                 st->draw_routine = &fast_draw_16;
 335                                 st->bpp_size = sizeof(CARD16);
 336                                 break;
 337                         case 8:
 338                                 st->draw_routine = &fast_draw_8;
 339                                 st->bpp_size = sizeof(CARD8);
 340                                 break;
 341                         default:
 342                                 st->draw_routine = &generic_draw;
 343                                 break;
 344                 }
 345         } else {
 346                 st->draw_routine = &generic_draw;
 347         }
 348         init_round_lense(st);
 349
 350         for (i = 0; i < st->number; i++) {
 351                 new_rnd_coo(st,i);
 352                 if (st->number != 1)
 353                         st->xy_coo[i].r = (i*st->radius)/(st->number-1); /* "randomize" initial */
 354                 else
 355                          st->xy_coo[i].r = 0;
 356                 st->xy_coo[i].r_change = st->speed + (i%2)*2*(-st->speed);      /* values a bit */
 357                 st->xy_coo[i].xmove = st->speed + (i%2)*2*(-st->speed);
 358                 st->xy_coo[i].ymove = st->speed + (i%2)*2*(-st->speed);
 359         }
 360 }
 361
 362 /* example: initializes a "see-trough" matrix */
 363 /* static void make_null_lense(struct state *st)
 364 {
 365         int i, j;
 366         for (i = 0; i < 2*radius+speed+2; i++) {
 367                 for (j = 0 ; j < 2*radius+speed+2 ; j++) {
 368                         from[i][j][0]=i;
 369                         from[i][j][1]=j;
 370                 }
 371         }
 372 }
 373 */
 374 static void convert(struct state *st)
 375 {
 376         int *p;
 377         int i, j;
 378         st->fast_from = calloc(1, sizeof(int)*((st->buffer_map->bytes_per_line/st->bpp_size)*(2*st->radius+st->speed+2) + 2*st->radius+st->speed+2));
 379         if (st->fast_from == NULL) {
 380                 perror("distort");
 381                 exit(EXIT_FAILURE);
 382         }
 383         p = st->fast_from;
 384         for (i = 0; i < 2*st->radius+st->speed+2; i++) {
 385                 for (j = 0; j < 2*st->radius+st->speed+2; j++) {
 386                         *(p + i + j*st->buffer_map->bytes_per_line/st->bpp_size)
 387                                 = st->from[i][j][0] + st->xgwa.width*st->from[i][j][1];
 388                         if (*(p + i + j*st->buffer_map->bytes_per_line/st->bpp_size) < 0
 389                                         || *(p + i + j*st->buffer_map->bytes_per_line/st->bpp_size) >= st->orig_map->height*st->orig_map->width) {
 390                                 *(p + i + j*st->buffer_map->bytes_per_line/st->bpp_size) = 0;
 391                         }
 392                 }
 393         }
 394 }
 395
 396 /* makes a lense with the Radius=loop and centred in
 397  * the point (radius, radius)
 398  */
 399 static void make_round_lense(struct state *st, int radius, int loop)
 400 {
 401         int i, j;
 402
 403         for (i = 0; i < 2*radius+st->speed+2; i++) {
 404                 for(j = 0; j < ((0 == st->bpp_size) ? (2*radius+st->speed+2) : (st->buffer_map->bytes_per_line/st->bpp_size)); j++) {
 405                         double r, d;
 406                         r = sqrt ((i-radius)*(i-radius)+(j-radius)*(j-radius));
 407                         if (loop == 0)
 408                           d=0.0;
 409                         else
 410                           d=r/loop;
 411
 412                         if (r < loop-1) {
 413
 414                                 if (st->vortex) { /* vortex-twist effect */
 415                                         double angle;
 416                 /* this one-line formula for getting a nice rotation angle is borrowed
 417                  * (with permission) from the whirl plugin for gimp,
 418                  * Copyright (C) 1996 Federico Mena Quintero
 419                  */
 420                 /* 5 is just a constant used because it looks good :) */
 421                                         angle = 5*(1-d)*(1-d);
 422
 423         /* Avoid atan2: DOMAIN error message */
 424                                         if ((radius-j) == 0.0 && (radius-i) == 0.0) {
 425                                                 st->from[i][j][0] = radius + cos(angle)*r;
 426                                                 st->from[i][j][1] = radius + sin(angle)*r;
 427                                         } else {
 428                                                 st->from[i][j][0] = radius +
 429                                                         cos(angle - atan2(radius-j, -(radius-i)))*r;
 430                                                 st->from[i][j][1] = radius +
 431                                                         sin(angle - atan2(radius-j, -(radius-i)))*r;
 432                                         }
 433                                         if (st->magnify) {
 434                                                 r = sin(d*M_PI_2);
 435                                                 if (st->blackhole && r != 0) /* blackhole effect */
 436                                                         r = 1/r;
 437                                                 st->from[i][j][0] = radius + (st->from[i][j][0]-radius)*r;
 438                                                 st->from[i][j][1] = radius + (st->from[i][j][1]-radius)*r;
 439                                         }
 440                                 } else { /* default is to magnify */
 441                                         r = sin(d*M_PI_2);
 442
 443         /* raising r to different power here gives different amounts of
 444          * distortion, a negative value sucks everything into a black hole
 445          */
 446                                 /*      r = r*r; */
 447                                         if (st->blackhole && r != 0) /* blackhole effect */
 448                                                 r = 1/r;
 449                                                                         /* bubble effect (and blackhole) */
 450                                         st->from[i][j][0] = radius + (i-radius)*r;
 451                                         st->from[i][j][1] = radius + (j-radius)*r;
 452                                 }
 453                         } else { /* not inside loop */
 454                                 st->from[i][j][0] = i;
 455                                 st->from[i][j][1] = j;
 456                         }
 457                 }
 458         }
 459
 460         /* this is really just a quick hack to keep both the compability mode with all depths and still
 461          * allow the custom optimized draw routines with the minimum amount of work */
 462         if (0 != st->bpp_size) {
 463                 convert(st);
 464         }
 465 }
 466
 467 #ifndef EXIT_FAILURE
 468 # define EXIT_FAILURE -1
 469 #endif
 470
 471 static void allocate_lense(struct state *st)
 472 {
 473         int i, j;
 474         int s = ((0 != st->bpp_size) ? (st->buffer_map->bytes_per_line/st->bpp_size) : (2*st->radius+st->speed+2));
 475         /* maybe this should be redone so that from[][][] is in one block;
 476          * then pointers could be used instead of arrays in some places (and
 477          * maybe give a speedup - maybe also consume less memory)
 478          */
 479         st->from = (int ***)malloc(s*sizeof(int **));
 480         if (st->from == NULL) {
 481                 perror("distort");
 482                 exit(EXIT_FAILURE);
 483         }
 484         for (i = 0; i < s; i++) {
 485                 st->from[i] = (int **)malloc((2*st->radius+st->speed+2) * sizeof(int *));
 486                 if (st->from[i] == NULL) {
 487                         perror("distort");
 488                         exit(EXIT_FAILURE);
 489                 }
 490                 for (j = 0; j < s; j++) {
 491                         st->from[i][j] = (int *)malloc(2 * sizeof(int));
 492                         if (st->from[i][j] == NULL) {
 493                                 perror("distort");
 494                                 exit(EXIT_FAILURE);
 495                         }
 496                 }
 497         }
 498 }
 499
 500 /* from_array in an array containing precalculated from matrices,
 501  * this is a double faced mem vs speed trade, it's faster, but eats
 502  * _a lot_ of mem for large radius (is there a bug here? I can't see it)
 503  */
 504 static void init_round_lense(struct state *st)
 505 {
 506         int k;
 507
 508         if (st->effect == &swamp_thing) {
 509                 st->from_array = (int ****)malloc((st->radius+1)*sizeof(int ***));
 510                 for (k=0; k <= st->radius; k++) {
 511                         allocate_lense(st);
 512                         make_round_lense(st, st->radius, k);
 513                         st->from_array[k] = st->from;
 514                 }
 515         } else { /* just allocate one from[][][] */
 516                 allocate_lense(st);
 517                 make_round_lense(st, st->radius,st->radius);
 518         }
 519 }
 520
 521 /* If fast_draw_8, fast_draw_16 or fast_draw_32 are to be used, the following properties
 522  * of the src and dest XImages must hold (otherwise the generic, slooow, method provided
 523  * by X is to be used):
 524  *      src->byte_order == dest->byte_order
 525  *      src->format == ZPixmap && dest->format == ZPixmap
 526  *      src->depth == dest->depth == the depth the function in question asumes
 527  * x and y is the coordinates in src from where to cut out the image from,
 528  * distort_matrix is a precalculated array of how to distort the matrix
 529  */
 530
 531 static void fast_draw_8(struct state *st, XImage *src, XImage *dest, int x, int y, int *distort_matrix)
 532 {
 533         CARD8 *u = (CARD8 *)dest->data;
 534         CARD8 *t = (CARD8 *)src->data + x + y*src->bytes_per_line/sizeof(CARD8);
 535
 536         while (u < (CARD8 *)(dest->data + sizeof(CARD8)*dest->height
 537                                 *dest->bytes_per_line/sizeof(CARD8))) {
 538                 *u++ = t[*distort_matrix++];
 539         }
 540 }
 541
 542 static void fast_draw_16(struct state *st, XImage *src, XImage *dest, int x, int y, int *distort_matrix)
 543 {
 544         CARD16 *u = (CARD16 *)dest->data;
 545         CARD16 *t = (CARD16 *)src->data + x + y*src->bytes_per_line/sizeof(CARD16);
 546
 547         while (u < (CARD16 *)(dest->data + sizeof(CARD16)*dest->height
 548                                 *dest->bytes_per_line/sizeof(CARD16))) {
 549                 *u++ = t[*distort_matrix++];
 550         }
 551 }
 552
 553 static void fast_draw_32(struct state *st, XImage *src, XImage *dest, int x, int y, int *distort_matrix)
 554 {
 555         CARD32 *u = (CARD32 *)dest->data;
 556         CARD32 *t = (CARD32 *)src->data + x + y*src->bytes_per_line/sizeof(CARD32);
 557
 558         while (u < (CARD32 *)(dest->data + sizeof(CARD32)*dest->height
 559                                 *dest->bytes_per_line/sizeof(CARD32))) {
 560                 *u++ = t[*distort_matrix++];
 561         }
 562 }
 563
 564 static void generic_draw(struct state *st, XImage *src, XImage *dest, int x, int y, int *distort_matrix)
 565 {
 566         int i, j;
 567         for (i = 0; i < dest->width; i++)
 568                 for (j = 0; j < dest->height; j++)
 569                         if (st->from[i][j][0] + x >= 0 &&
 570                                         st->from[i][j][0] + x < src->width &&
 571                                         st->from[i][j][1] + y >= 0 &&
 572                                         st->from[i][j][1] + y < src->height)
 573                                 XPutPixel(dest, i, j,
 574                                                 XGetPixel(src,
 575                                                         st->from[i][j][0] + x,
 576                                                         st->from[i][j][1] + y));
 577 }
 578
 579 /* generate an XImage of from[][][] and draw it on the screen */
 580 static void plain_draw(struct state *st, int k)
 581 {
 582         if (st->xy_coo[k].x+2*st->radius+st->speed+2 > st->orig_map->width ||
 583                         st->xy_coo[k].y+2*st->radius+st->speed+2 > st->orig_map->height)
 584                 return;
 585
 586         st->draw_routine(st, st->orig_map, st->buffer_map, st->xy_coo[k].x, st->xy_coo[k].y, st->fast_from);
 587
 588         put_xshm_image(st->dpy, st->window, st->gc, st->buffer_map, 0, 0, st->xy_coo[k].x, st->xy_coo[k].y,
 589                        2*st->radius+st->speed+2, 2*st->radius+st->speed+2, &st->shm_info);
 590 }
 591
 592
 593 /* generate an XImage from the reflect algoritm submitted by
 594  * Randy Zack <randy@acucorp.com>
 595  * draw really got too big and ugly so I split it up
 596  * it should be possible to use the from[][] to speed it up
 597  * (once I figure out the algorithm used :)
 598  */
 599 static void reflect_draw(struct state *st, int k)
 600 {
 601         int i, j;
 602         int     cx, cy;
 603         int     ly, lysq, lx, ny, dist, rsq = st->radius * st->radius;
 604
 605         cx = cy = st->radius;
 606         if (st->xy_coo[k].ymove > 0)
 607                 cy += st->speed;
 608         if (st->xy_coo[k].xmove > 0)
 609                 cx += st->speed;
 610
 611         for(i = 0 ; i < 2*st->radius+st->speed+2; i++) {
 612                 ly = i - cy;
 613                 lysq = ly * ly;
 614                 ny = st->xy_coo[k].y + i;
 615                 if (ny >= st->orig_map->height) ny = st->orig_map->height-1;
 616                 for(j = 0 ; j < 2*st->radius+st->speed+2 ; j++) {
 617                         lx = j - cx;
 618                         dist = lx * lx + lysq;
 619                         if (dist > rsq ||
 620                                 ly < -st->radius || ly > st->radius ||
 621                                 lx < -st->radius || lx > st->radius)
 622                                 XPutPixel( st->buffer_map, j, i,
 623                                                    XGetPixel( st->orig_map, st->xy_coo[k].x + j, ny ));
 624                         else if (dist == 0)
 625                                 XPutPixel( st->buffer_map, j, i, st->black_pixel );
 626                         else {
 627                                 int     x = st->xy_coo[k].x + cx + (lx * rsq / dist);
 628                                 int     y = st->xy_coo[k].y + cy + (ly * rsq / dist);
 629                                 if (x < 0 || x >= st->xgwa.width ||
 630                                         y < 0 || y >= st->xgwa.height)
 631                                         XPutPixel( st->buffer_map, j, i, st->black_pixel );
 632                                 else
 633                                         XPutPixel( st->buffer_map, j, i,
 634                                                            XGetPixel( st->orig_map, x, y ));
 635                         }
 636                 }
 637         }
 638
 639         XPutImage(st->dpy, st->window, st->gc, st->buffer_map, 0, 0, st->xy_coo[k].x, st->xy_coo[k].y,
 640                         2*st->radius+st->speed+2, 2*st->radius+st->speed+2);
 641 }
 642
 643 /* create a new, random coordinate, that won't interfer with any other
 644  * coordinates, as the drawing routines would be significantly slowed
 645  * down if they were to handle serveral layers of distortions
 646  */
 647 static void new_rnd_coo(struct state *st, int k)
 648 {
 649         int i;
 650     int loop = 0;
 651
 652         st->xy_coo[k].x = (random() % (st->xgwa.width-2*st->radius));
 653         st->xy_coo[k].y = (random() % (st->xgwa.height-2*st->radius));
 654
 655         for (i = 0; i < st->number; i++) {
 656                 if (i != k) {
 657                         if ((abs(st->xy_coo[k].x - st->xy_coo[i].x) <= 2*st->radius+st->speed+2)
 658                          && (abs(st->xy_coo[k].y - st->xy_coo[i].y) <= 2*st->radius+st->speed+2)) {
 659                                 st->xy_coo[k].x = (random() % (st->xgwa.width-2*st->radius));
 660                                 st->xy_coo[k].y = (random() % (st->xgwa.height-2*st->radius));
 661                                 i=-1; /* ugly */
 662                         }
 663                 }
 664         if (loop++ > 1000) return;  /* let's not get stuck */
 665         }
 666 }
 667
 668 /* move lens and handle bounces with walls and other lenses */
 669 static void move_lense(struct state *st, int k)
 670 {
 671         int i;
 672
 673         if (st->xy_coo[k].x + 2*st->radius + st->speed + 2 >= st->xgwa.width)
 674                 st->xy_coo[k].xmove = -abs(st->xy_coo[k].xmove);
 675         if (st->xy_coo[k].x <= st->speed)
 676                 st->xy_coo[k].xmove = abs(st->xy_coo[k].xmove);
 677         if (st->xy_coo[k].y + 2*st->radius + st->speed + 2 >= st->xgwa.height)
 678                 st->xy_coo[k].ymove = -abs(st->xy_coo[k].ymove);
 679         if (st->xy_coo[k].y <= st->speed)
 680                 st->xy_coo[k].ymove = abs(st->xy_coo[k].ymove);
 681
 682         st->xy_coo[k].x = st->xy_coo[k].x + st->xy_coo[k].xmove;
 683         st->xy_coo[k].y = st->xy_coo[k].y + st->xy_coo[k].ymove;
 684
 685         /* bounce against othe lenses */
 686         for (i = 0; i < st->number; i++) {
 687                 if ((i != k)
 688
 689 /* This commented test is for rectangular lenses (not currently used) and
 690  * the one used is for circular ones
 691                 && (abs(xy_coo[k].x - xy_coo[i].x) <= 2*radius)
 692                 && (abs(xy_coo[k].y - xy_coo[i].y) <= 2*radius)) { */
 693
 694                 && ((st->xy_coo[k].x - st->xy_coo[i].x)*(st->xy_coo[k].x - st->xy_coo[i].x)
 695                   + (st->xy_coo[k].y - st->xy_coo[i].y)*(st->xy_coo[k].y - st->xy_coo[i].y)
 696                         <= 2*st->radius*2*st->radius)) {
 697
 698                         int x, y;
 699                         x = st->xy_coo[k].xmove;
 700                         y = st->xy_coo[k].ymove;
 701                         st->xy_coo[k].xmove = st->xy_coo[i].xmove;
 702                         st->xy_coo[k].ymove = st->xy_coo[i].ymove;
 703                         st->xy_coo[i].xmove = x;
 704                         st->xy_coo[i].ymove = y;
 705                 }
 706         }
 707
 708 }
 709
 710 /* make xy_coo[k] grow/shrink */
 711 static void swamp_thing(struct state *st, int k)
 712 {
 713         if (st->xy_coo[k].r >= st->radius)
 714                 st->xy_coo[k].r_change = -abs(st->xy_coo[k].r_change);
 715
 716         if (st->xy_coo[k].r <= 0) {
 717                 st->from = st->from_array[0];
 718                 st->draw(st,k);
 719                 st->xy_coo[k].r_change = abs(st->xy_coo[k].r_change);
 720                 new_rnd_coo(st,k);
 721                 st->xy_coo[k].r=st->xy_coo[k].r_change;
 722                 return;
 723         }
 724
 725         st->xy_coo[k].r = st->xy_coo[k].r + st->xy_coo[k].r_change;
 726
 727         if (st->xy_coo[k].r >= st->radius)
 728                 st->xy_coo[k].r = st->radius;
 729         if (st->xy_coo[k].r <= 0)
 730                 st->xy_coo[k].r=0;
 731
 732         st->from = st->from_array[st->xy_coo[k].r];
 733 }
 734
 735
 736 static unsigned long
 737 distort_draw (Display *dpy, Window window, void *closure)
 738 {
 739   struct state *st = (struct state *) closure;
 740   int k;
 741
 742   if (st->img_loader)   /* still loading */
 743     {
 744       st->img_loader = load_image_async_simple (st->img_loader, 0, 0, 0, 0, 0);
 745       if (! st->img_loader) {  /* just finished */
 746         distort_finish_loading (st);
 747       }
 748       return st->delay;
 749     }
 750
 751   if (!st->img_loader &&
 752       st->start_time + st->duration < time ((time_t *) 0)) {
 753     if (st->pm) XFreePixmap (st->dpy, st->pm);
 754     st->pm = XCreatePixmap (st->dpy, st->window,
 755                             st->xgwa.width, st->xgwa.height, st->xgwa.depth);
 756     st->img_loader = load_image_async_simple (0, st->xgwa.screen, st->window,
 757                                               st->pm, 0, 0);
 758     return st->delay;
 759   }
 760
 761   for (k = 0; k < st->number; k++) {
 762     st->effect(st,k);
 763     st->draw(st,k);
 764   }
 765   return st->delay;
 766 }
 767
 768 static void
 769 distort_reshape (Display *dpy, Window window, void *closure,
 770                  unsigned int w, unsigned int h)
 771 {
 772   struct state *st = (struct state *) closure;
 773   XGetWindowAttributes (st->dpy, st->window, &st->xgwa);
 774   /* XClearWindow (dpy, window); */
 775   /* Why doesn't this work? */
 776   if (st->orig_map)  /* created in distort_finish_loading, might be early */
 777     XPutImage (st->dpy, st->window, st->gc, st->orig_map,
 778                0, 0, st->orig_map->width, st->orig_map->height, 0, 0);
 779 }
 780
 781 static Bool
 782 distort_event (Display *dpy, Window window, void *closure, XEvent *event)
 783 {
 784   struct state *st = (struct state *) closure;
 785   if (screenhack_event_helper (dpy, window, event))
 786     {
 787       distort_reset(st);
 788       return True;
 789     }
 790   return False;
 791 }
 792
 793 static void
 794 distort_free (Display *dpy, Window window, void *closure)
 795 {
 796   struct state *st = (struct state *) closure;
 797   XFreeGC (st->dpy, st->gc);
 798   if (st->pm) XFreePixmap (dpy, st->pm);
 799   if (st->orig_map) XDestroyImage (st->orig_map);
 800   if (st->buffer_map) destroy_xshm_image (st->dpy, st->buffer_map, &st->shm_info);
 801   if (st->from) free (st->from);
 802   if (st->fast_from) free (st->fast_from);
 803   if (st->from_array) free (st->from_array);
 804   free (st);
 805 }
 806
 807
 808 \f
 809
 810 static const char *distort_defaults [] = {
 811         "*dontClearRoot:                True",
 812         "*background:                   Black",
 813     "*fpsSolid:                         true",
 814 #ifdef __sgi    /* really, HAVE_READ_DISPLAY_EXTENSION */
 815         "*visualID:                     Best",
 816 #endif
 817
 818         "*delay:                        20000",
 819     "*duration:                 120",
 820         "*radius:                       0",
 821         "*speed:                        0",
 822         "*number:                       0",
 823         "*slow:                         False",
 824         "*vortex:                       False",
 825         "*magnify:                      False",
 826         "*reflect:                      False",
 827         "*blackhole:            False",
 828         "*effect:                   none",
 829 #ifdef HAVE_XSHM_EXTENSION
 830         "*useSHM:                       False",         /* xshm turns out not to help. */
 831 #endif /* HAVE_XSHM_EXTENSION */
 832 #ifdef HAVE_MOBILE
 833   "*ignoreRotation:     True",
 834   "*rotateImages:       True",
 835 #endif
 836         0
 837 };
 838
 839 static XrmOptionDescRec distort_options [] = {
 840   { "-delay",     ".delay",       XrmoptionSepArg, 0 },
 841   { "-duration",  ".duration",    XrmoptionSepArg, 0 },
 842   { "-radius",    ".radius",      XrmoptionSepArg, 0 },
 843   { "-speed",     ".speed",       XrmoptionSepArg, 0 },
 844   { "-number",    ".number",      XrmoptionSepArg, 0 },
 845
 846   { "-effect",    ".effect",      XrmoptionSepArg, 0 },
 847   { "-swamp",     ".effect",      XrmoptionNoArg, "swamp"  },
 848   { "-bounce",    ".effect",      XrmoptionNoArg, "bounce" },
 849
 850   { "-reflect",   ".reflect",     XrmoptionNoArg, "True" },
 851   { "-vortex",    ".vortex",      XrmoptionNoArg, "True" },
 852   { "-magnify",   ".magnify",     XrmoptionNoArg, "True" },
 853   { "-blackhole", ".blackhole",   XrmoptionNoArg, "True" },
 854   { "-slow",      ".slow",        XrmoptionNoArg, "True" },
 855 #ifdef HAVE_XSHM_EXTENSION
 856   { "-shm",       ".useSHM",      XrmoptionNoArg, "True" },
 857   { "-no-shm",    ".useSHM",      XrmoptionNoArg, "False" },
 858 #endif /* HAVE_XSHM_EXTENSION */
 859   { 0, 0, 0, 0 }
 860 };
 861
 862 XSCREENSAVER_MODULE ("Distort", distort)