X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?p=xscreensaver;a=blobdiff_plain;f=hacks%2Fglitchpeg.c;fp=hacks%2Fglitchpeg.c;h=4f3b0520de20a279804468335c1d0c78d0a75ec2;hp=0000000000000000000000000000000000000000;hb=c85f503f5793839a6be4c818332aca4a96927bb2;hpb=78add6e627ee5f10e1fa6f3852602ea5066eee5a

diff --git a/hacks/glitchpeg.c b/hacks/glitchpeg.c
new file mode 100644
index 00000000..4f3b0520
--- /dev/null
+++ b/hacks/glitchpeg.c
@@ -0,0 +1,440 @@
+/* glitchpeg, Copyright (c) 2018 Jamie Zawinski <jwz@jwz.org>
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that
+ * copyright notice and this permission notice appear in supporting
+ * documentation.  No representations are made about the suitability of this
+ * software for any purpose.  It is provided "as is" without express or 
+ * implied warranty.
+ *
+ * Insert errors into an image file, then display the corrupted result.
+ *
+ * This only works on X11 and MacOS because iOS and Android don't have
+ * access to the source files of images, only the decoded image data.
+ */
+
+#include "screenhack.h"
+#include "ximage-loader.h"
+
+#ifndef HAVE_JWXYZ
+# include <X11/Intrinsic.h>   /* for XtInputId, etc */
+#endif
+
+#include <sys/stat.h>
+
+#undef countof
+#define countof(x) (sizeof((x))/sizeof((*x)))
+
+struct state {
+  Display *dpy;
+  Window window;
+  GC gc;
+  XWindowAttributes xgwa;
+  int delay;
+  int count;
+  int duration;
+  time_t start_time;
+  unsigned char *image_data; unsigned long image_size;
+  XtInputId pipe_id;
+  FILE *pipe;
+  Bool button_down_p;
+};
+
+
+static Bool
+bigendian (void)
+{
+  union { int i; char c[sizeof(int)]; } u;
+  u.i = 1;
+  return !u.c[0];
+}
+
+
+/* Given a bitmask, returns the position and width of the field.
+   Duplicated from ximage-loader.c.
+ */
+static void
+decode_mask (unsigned long mask, unsigned long *pos_ret,
+             unsigned long *size_ret)
+{
+  int i;
+  for (i = 0; i < 32; i++)
+    if (mask & (1L << i))
+      {
+        int j = 0;
+        *pos_ret = i;
+        for (; i < 32; i++, j++)
+          if (! (mask & (1L << i)))
+            break;
+        *size_ret = j;
+        return;
+      }
+}
+
+
+/* Renders a scaled, cropped version of the RGBA XImage onto the window.
+ */
+static void
+draw_image (Display *dpy, Window window, Visual *v, GC gc, 
+            int w, int h, int depth, XImage *in)
+{
+  XImage *out;
+  int x, y, w2, h2, xoff, yoff;
+  double xs, ys, s;
+
+  unsigned long crpos=0, cgpos=0, cbpos=0, capos=0; /* bitfield positions */
+  unsigned long srpos=0, sgpos=0, sbpos=0;
+  unsigned long srmsk=0, sgmsk=0, sbmsk=0;
+  unsigned long srsiz=0, sgsiz=0, sbsiz=0;
+
+# ifdef HAVE_JWXYZ
+  // BlackPixel has alpha: 0xFF000000.
+  unsigned long black = BlackPixelOfScreen (DefaultScreenOfDisplay (dpy));
+#else
+  unsigned long black = 0;
+# endif
+
+  xs = in->width  / (double) w;
+  ys = in->height / (double) h;
+  s = (xs > ys ? ys : xs);
+  w2 = in->width  / s;
+  h2 = in->height / s;
+  xoff = (w - w2) / 2;
+  yoff = (h - h2) / 2;
+
+  /* Create a new image in the depth and bit-order of the server. */
+  out = XCreateImage (dpy, v, depth, ZPixmap, 0, 0, w, h, 8, 0);
+  out->bitmap_bit_order = in->bitmap_bit_order;
+  out->byte_order = in->byte_order;
+
+  out->bitmap_bit_order = BitmapBitOrder (dpy);
+  out->byte_order = ImageByteOrder (dpy);
+
+  out->data = (char *) malloc (out->height * out->bytes_per_line);
+  if (!out->data) abort();
+
+  /* Find the server's color masks.
+     We could cache this and just do it once, but it's a small number
+     of instructions compared to the per-pixel operations happening next.
+   */
+  srmsk = out->red_mask;
+  sgmsk = out->green_mask;
+  sbmsk = out->blue_mask;
+
+  if (!(srmsk && sgmsk && sbmsk)) abort();  /* No server color masks? */
+
+  decode_mask (srmsk, &srpos, &srsiz);
+  decode_mask (sgmsk, &sgpos, &sgsiz);
+  decode_mask (sbmsk, &sbpos, &sbsiz);
+
+  /* 'in' is RGBA in client endianness.  Convert to what the server wants. */
+  if (bigendian())
+    crpos = 24, cgpos = 16, cbpos =  8, capos =  0;
+  else
+    crpos =  0, cgpos =  8, cbpos = 16, capos = 24;
+
+  /* Iterate the destination rectangle and pull in the corresponding
+     scaled and cropped source pixel, or black. Nearest-neighbor is fine.
+   */
+  for (y = 0; y < out->height; y++)
+    {
+      int iy = (out->height - y - yoff - 1) * s;
+      for (x = 0; x < out->width; x++)
+        {
+          int ix = (x - xoff) * s;
+          unsigned long p = (ix >= 0 && ix < in->width &&
+                             iy >= 0 && iy < in->height
+                             ? XGetPixel (in, ix, iy)
+                             : black);
+       /* unsigned char a = (p >> capos) & 0xFF; */
+          unsigned char b = (p >> cbpos) & 0xFF;
+          unsigned char g = (p >> cgpos) & 0xFF;
+          unsigned char r = (p >> crpos) & 0xFF;
+          XPutPixel (out, x, y, ((r << srpos) |
+                                 (g << sgpos) |
+                                 (b << sbpos) |
+                                 black));
+        }
+    }
+
+  XPutImage (dpy, window, gc, out, 0, 0, 0, 0, out->width, out->height);
+  XDestroyImage (out);
+}
+
+
+# define BACKSLASH(c) \
+  (! ((c >= 'a' && c <= 'z') || \
+      (c >= 'A' && c <= 'Z') || \
+      (c >= '0' && c <= '9') || \
+      c == '.' || c == '_' || c == '-' || c == '+' || c == '/'))
+
+/* Gets the name of an image file to load by running xscreensaver-getimage-file
+   at the end of a pipe.  This can be very slow!
+   Duplicated from utils/grabclient.c
+ */
+static FILE *
+open_image_name_pipe (void)
+{
+  char *s;
+
+  /* /bin/sh on OS X 10.10 wipes out the PATH. */
+  const char *path = getenv("PATH");
+  char *cmd = s = malloc (strlen(path) * 2 + 100);
+  strcpy (s, "/bin/sh -c 'export PATH=");
+  s += strlen (s);
+  while (*path) {
+    char c = *path++;
+    if (BACKSLASH(c)) *s++ = '\\';
+    *s++ = c;
+  }
+  strcpy (s, "; ");
+  s += strlen (s);
+
+  strcpy (s, "xscreensaver-getimage-file --name --absolute");
+  s += strlen (s);
+
+  strcpy (s, "'");
+  s += strlen (s);
+
+  *s = 0;
+
+  FILE *pipe = popen (cmd, "r");
+  free (cmd);
+  return pipe;
+}
+
+
+/* Duplicated from utils/grabclient.c */
+static void
+xscreensaver_getimage_file_cb (XtPointer closure, int *source, XtInputId *id)
+{
+  /* This is not called from a signal handler, so doing stuff here is fine.
+   */
+  struct state *st = (struct state *) closure;
+  char buf[10240];
+  char *file = buf;
+  FILE *fp;
+  struct stat stat;
+  int n;
+  unsigned char *s;
+  int L;
+
+  *buf = 0;
+  fgets (buf, sizeof(buf)-1, st->pipe);
+  pclose (st->pipe);
+  st->pipe = 0;
+  XtRemoveInput (st->pipe_id);
+  st->pipe_id = 0;
+
+  /* strip trailing newline */
+  L = strlen(buf);
+  while (L > 0 && (buf[L-1] == '\r' || buf[L-1] == '\n'))
+    buf[--L] = 0;
+
+  fp = fopen (file, "r");
+  if (! fp)
+    {
+      fprintf (stderr, "%s: unable to read %s\n", progname, file);
+      return;
+    }
+
+  if (fstat (fileno (fp), &stat))
+    {
+      fprintf (stderr, "%s: %s: stat failed\n", progname, file);
+      return;
+    }
+
+  if (st->image_data) free (st->image_data);
+  st->image_size = stat.st_size;
+  st->image_data = malloc (st->image_size);
+  
+  s = st->image_data;
+  do {
+    n = fread (s, 1, st->image_data + st->image_size - s, fp);
+    if (n > 0) s += n;
+  } while (n > 0);
+
+  fclose (fp);
+
+  /* fprintf (stderr, "loaded %s (%lu)\n", file, st->image_size); */
+
+  st->start_time = time((time_t *) 0);
+}
+
+
+static void *
+glitchpeg_init (Display *dpy, Window window)
+{
+  struct state *st = (struct state *) calloc (1, sizeof(*st));
+  XGCValues gcv;
+
+  st->dpy = dpy;
+  st->window = window;
+  st->gc = XCreateGC (dpy, window, 0, &gcv);
+
+  XGetWindowAttributes (st->dpy, st->window, &st->xgwa);
+
+  st->delay = get_integer_resource (st->dpy, "delay", "Integer");
+  if (st->delay < 1) st->delay = 1;
+
+  st->duration = get_integer_resource (st->dpy, "duration", "Integer");
+  if (st->duration < 0) st->duration = 0;
+
+  st->count = get_integer_resource (st->dpy, "count", "Integer");
+  if (st->count < 1) st->count = 1;
+
+  XClearWindow (st->dpy, st->window);
+
+  return st;
+}
+
+
+static unsigned long
+glitchpeg_draw (Display *dpy, Window window, void *closure)
+{
+  struct state *st = (struct state *) closure;
+
+  if ((!st->image_data ||
+       time((time_t *) 0) >= st->start_time + st->duration) &&
+      !st->pipe)
+    {
+      /* Time to reload */
+      st->pipe = open_image_name_pipe();
+      st->pipe_id =
+        XtAppAddInput (XtDisplayToApplicationContext (dpy), 
+                       fileno (st->pipe),
+                       (XtPointer) (XtInputReadMask | XtInputExceptMask),
+                       xscreensaver_getimage_file_cb, (XtPointer) st);
+    }
+
+  if (st->image_data && !st->button_down_p)
+    {
+      int n;
+      XImage *image;
+      unsigned char *glitched = malloc (st->image_size);
+      int nn = random() % st->count;
+      if (nn <= 0) nn = 1;
+
+      memcpy (glitched, st->image_data, st->image_size);
+
+      for (n = 0; n < nn; n++)
+        {
+          int start = 255;
+          int end = st->image_size - 255;
+          int size = end - start;
+          Bool byte_p = True;  /* random() % 100; */
+          if (size <= 100) break;
+          if (byte_p)
+            {
+              int i = start + (random() % size);
+              if (!(random() % 10))
+                /* Take one random byte and randomize it. */
+                glitched[i] = random() % 0xFF; 
+              else
+                /* Take one random byte and add 5% to it. */
+                glitched[i] += 
+                  (1 + (random() % 0x0C)) * ((random() & 1) ? 1 : -1);
+            }
+          else
+            {
+              /* Take two randomly-sized chunks of the file and swap them.
+                 This tends to just destroy the image.  Doesn't look good. */
+              int s2 = 2 + size * 0.05;
+              char *swap = malloc (s2);
+              int start1 = start + (random() % (size - s2));
+              int start2 = start + (random() % (size - s2));
+              memcpy (glitched + start1, swap, s2);
+              memmove (glitched + start2, glitched + start1, s2);
+              memcpy (swap, glitched + start2, s2);
+              free (swap);
+            }
+        }
+
+      image = image_data_to_ximage (dpy, st->xgwa.visual,
+                                    glitched, st->image_size);
+      free (glitched);
+
+      if (image)  /* Might be null if decode fails */
+        {
+          draw_image (dpy, window, st->xgwa.visual, st->gc,
+                      st->xgwa.width, st->xgwa.height, st->xgwa.depth,
+                      image);
+          XDestroyImage (image);
+        }
+    }
+
+  return st->delay;
+}
+
+
+static void
+glitchpeg_reshape (Display *dpy, Window window, void *closure, 
+                 unsigned int w, unsigned int h)
+{
+  struct state *st = (struct state *) closure;
+  XGetWindowAttributes (st->dpy, st->window, &st->xgwa);
+}
+
+
+static Bool
+glitchpeg_event (Display *dpy, Window window, void *closure, XEvent *event)
+{
+  struct state *st = (struct state *) closure;
+  if (event->xany.type == ButtonPress)
+    {
+      st->button_down_p = True;
+      return True;
+    }
+  else if (event->xany.type == ButtonRelease)
+    {
+      st->button_down_p = False;
+      return True;
+    }
+  else if (screenhack_event_helper (dpy, window, event))
+    {
+      st->start_time = 0;  /* reload */
+      return True;
+    }
+
+  return False;
+}
+
+
+static void
+glitchpeg_free (Display *dpy, Window window, void *closure)
+{
+  struct state *st = (struct state *) closure;
+  XFreeGC (dpy, st->gc);
+  if (st->pipe_id) XtRemoveInput (st->pipe_id);
+  if (st->pipe) fclose (st->pipe);
+  if (st->image_data) free (st->image_data);
+  free (st);
+}
+
+
+static const char *glitchpeg_defaults [] = {
+  ".background:			black",
+  ".foreground:			white",
+  ".lowrez:                     True",
+  "*fpsSolid:			true",
+  "*delay:			30000",
+  "*duration:			120",
+  "*count:			100",
+  "*grabDesktopImages:		False",   /* HAVE_JWXYZ */
+  "*chooseRandomImages:		True",    /* HAVE_JWXYZ */
+#ifdef HAVE_MOBILE
+  "*ignoreRotation:             True",
+  "*rotateImages:               True",
+#endif
+  0
+};
+
+static XrmOptionDescRec glitchpeg_options [] = {
+  { "-delay",		".delay",		XrmoptionSepArg, 0 },
+  { "-duration",	".duration",		XrmoptionSepArg, 0 },
+  { "-count",		".count",		XrmoptionSepArg, 0 },
+  { 0, 0, 0, 0 }
+};
+
+XSCREENSAVER_MODULE ("GlitchPEG", glitchpeg)