ftp://ftp.uni-heidelberg.de/pub/X11/contrib/applications/xscreensaver-2.07.tar.gz

[xscreensaver] / hacks / moire.c

diff --git a/hacks/moire.c b/hacks/moire.c
new file mode 100644 (file)
index 0000000..7d9798c
--- /dev/null
+++ b/hacks/moire.c
@@ -0,0 +1,193 @@
+/* xscreensaver, Copyright (c) 1997 Jamie Zawinski <jwz@netscape.com>
+ *
+ * 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.
+ *
+ * Concept snarfed from Michael D. Bayne in
+ * http://www.go2net.com/internet/deep/1997/04/16/body.html
+ */
+
+#include "screenhack.h"
+#include <X11/Xutil.h>
+#include <stdio.h>
+
+int offset = 0;
+XColor *colors = 0;
+int ncolors = 0;
+GC gc = 0;
+unsigned long fg_pixel = 0;
+unsigned long bg_pixel = 0;
+
+static void
+init_moire (Display *dpy, Window window)
+{
+  int oncolors;
+  int i;
+  int fgh, bgh;
+  double fgs, fgv, bgs, bgv;
+  XWindowAttributes xgwa;
+  XColor fgc, bgc;
+  XGCValues gcv;
+  XGetWindowAttributes (dpy, window, &xgwa);
+
+  offset = get_integer_resource ("offset", "Integer");
+  if (offset < 2) offset = 2;
+
+ MONO:
+  if (colors)
+    {
+      for (i = 0; i < ncolors; i++)
+       XFreeColors (dpy, xgwa.colormap, &colors[i].pixel, 1, 0);
+      free(colors);
+      colors = 0;
+    }
+
+  if (mono_p)
+    {
+      fg_pixel = WhitePixelOfScreen (DefaultScreenOfDisplay(dpy));
+      bg_pixel = BlackPixelOfScreen (DefaultScreenOfDisplay(dpy));
+    }
+  else
+    {
+      fg_pixel = get_pixel_resource ("foreground", "Foreground", dpy,
+                                    xgwa.colormap);
+      bg_pixel = get_pixel_resource ("background", "Background", dpy,
+                                    xgwa.colormap);
+    }
+
+  if (mono_p)
+    {
+      offset *= 20;   /* compensate for lack of shading */
+      gcv.foreground = fg_pixel;
+    }
+  else
+    {
+      ncolors = get_integer_resource ("ncolors", "Integer");
+      if (ncolors < 2) ncolors = 2;
+      oncolors = ncolors;
+
+      fgc.flags = bgc.flags = DoRed|DoGreen|DoBlue;
+      if (get_boolean_resource("random","Boolean"))
+       {
+         fgc.red   = random() & 0xFFFF;
+         fgc.green = random() & 0xFFFF;
+         fgc.blue  = random() & 0xFFFF;
+         bgc.red   = random() & 0xFFFF;
+         bgc.green = random() & 0xFFFF;
+         bgc.blue  = random() & 0xFFFF;
+       }
+      else
+       {
+         fgc.pixel = fg_pixel;
+         bgc.pixel = bg_pixel;
+         XQueryColor (dpy, xgwa.colormap, &fgc);
+         XQueryColor (dpy, xgwa.colormap, &bgc);
+       }
+      rgb_to_hsv (fgc.red, fgc.green, fgc.blue, &fgh, &fgs, &fgv);
+      rgb_to_hsv (bgc.red, bgc.green, bgc.blue, &bgh, &bgs, &bgv);
+
+      colors = (XColor *) malloc (sizeof (XColor) * (ncolors+2));
+      memset(colors, 0, (sizeof (XColor) * (ncolors+2)));
+      make_color_ramp (dpy, xgwa.colormap,
+                      fgh, fgs, fgv, bgh, bgs, bgv,
+                      colors, &ncolors,
+                      True, True, False);
+      if (ncolors != oncolors)
+       fprintf(stderr, "%s: got %d of %d requested colors.\n",
+               progname, ncolors, oncolors);
+
+      if (ncolors <= 2)
+       {
+         mono_p = True;
+         goto MONO;
+       }
+
+      gcv.foreground = colors[0].pixel;
+    }
+  gc = XCreateGC (dpy, window, GCForeground, &gcv);
+}
+
+
+static void
+moire (Display *dpy, Window window, int offset, XColor *colors, int ncolors)
+{
+  long x, y, xo, yo;
+  int factor = (random() % offset) + 1;
+  XGCValues gcv;
+  XWindowAttributes xgwa;
+  XImage *image;
+  int depth;
+  XGetWindowAttributes (dpy, window, &xgwa);
+
+  xo = (random() % xgwa.width)  - xgwa.width/2;
+  yo = (random() % xgwa.height) - xgwa.height/2;
+
+  depth = visual_depth(DefaultScreenOfDisplay(dpy), xgwa.visual);
+  image = XCreateImage (dpy, xgwa.visual,
+                       depth, ZPixmap, 0,       /* depth, format, offset */
+                       0, xgwa.width, 1, 8, 0); /* data, w, h, pad, bpl */
+
+  image->data = (char *) malloc (((xgwa.width + 1) * depth / 8)
+                                * 2  /* uh, I dunno... */
+                                );
+
+  for (y = 0; y < xgwa.height; y++)
+    {
+      for (x = 0; x < xgwa.width; x++)
+       {
+         double xx = x + xo;
+         double yy = y + yo;
+         double i = ((xx * xx) + (yy * yy)) / (double) factor;
+         if (mono_p)
+           gcv.foreground = ((((long) i) & 1) ? fg_pixel : bg_pixel);
+         else
+           gcv.foreground = colors[((long) i) % ncolors].pixel;
+         XPutPixel (image, x, 0, gcv.foreground);
+       }
+      XPutImage (dpy, window, gc, image, 0, 0, 0, y, xgwa.width, 1);
+      XSync(dpy, False);
+    }
+  if (image->data) free(image->data);
+  image->data = 0;
+  XDestroyImage (image);
+}
+
+\f
+char *progclass = "Moire";
+
+char *defaults [] = {
+  "Moire.background:   blue",          /* to placate SGI */
+  "Moire.foreground:   red",
+  "*random:            true",
+  "*delay:             5",
+  "*ncolors:           64",
+  "*offset:            50",
+  0
+};
+
+XrmOptionDescRec options [] = {
+  { "-random",         ".random",      XrmoptionSepArg, 0 },
+  { "-delay",          ".delay",       XrmoptionSepArg, 0 },
+  { "-ncolors",                ".ncolors",     XrmoptionSepArg, 0 },
+  { "-offset",         ".offset",      XrmoptionSepArg, 0 },
+  { 0, 0, 0, 0 }
+};
+
+void
+screenhack (Display *dpy, Window window)
+{
+  int delay = get_integer_resource ("delay", "Integer");
+  while (1)
+    {
+      init_moire (dpy, window);
+      moire (dpy, window, offset, colors, ncolors);
+      XSync (dpy, True);
+      if (delay)
+       sleep(delay);
+    }
+}