--- /dev/null
+/* coral, by "Frederick G.M. Roeber" <roeber@netscape.com>, 15-jul-97.
+ *
+ * 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.
+ */
+
+#include "screenhack.h"
+#include "colors.h"
+
+static GC draw_gc;
+static unsigned int default_fg_pixel;
+#define NCOLORSMAX 200
+static XColor colors[NCOLORSMAX];
+static int ncolors = 0;
+static int colorindex = 0;
+static int colorsloth;
+
+static XPoint *walkers;
+static int nwalkers;
+static int width, widthb;
+static int height;
+
+static unsigned int *board;
+#define getdot(x,y) (board[(y*widthb)+(x>>5)] & (1<<(x & 31)))
+#define setdot(x,y) (board[(y*widthb)+(x>>5)] |= (1<<(x & 31)))
+
+
+static void
+init_coral(Display *dpy, Window window)
+{
+ XGCValues gcv;
+ Colormap cmap;
+ XWindowAttributes xgwa;
+ Bool writeable = False;
+ int seeds;
+ int density;
+ int i;
+
+ XClearWindow(dpy, window);
+ XGetWindowAttributes(dpy, window, &xgwa);
+ width = xgwa.width;
+ widthb = ((xgwa.width + 31) >> 5);
+ height = xgwa.height;
+ board = (unsigned int *)calloc(widthb * xgwa.height, sizeof(unsigned int));
+ if(!board) exit(1);
+ cmap = xgwa.colormap;
+ if( ncolors ) {
+ free_colors(dpy, cmap, colors, ncolors);
+ ncolors = 0;
+ }
+ gcv.foreground = default_fg_pixel = get_pixel_resource("foreground", "Foreground", dpy, cmap);
+ draw_gc = XCreateGC(dpy, window, GCForeground, &gcv);
+ ncolors = NCOLORSMAX;
+ make_uniform_colormap(dpy, xgwa.visual, cmap, colors, &ncolors, True, &writeable, False);
+ colorindex = random()%ncolors;
+
+ density = get_integer_resource("density", "Integer");
+ if( density < 1 ) density = 1;
+ if( density > 100 ) density = 90; /* more like mold than coral */
+ nwalkers = (width*height*density)/100;
+ walkers = (XPoint *)calloc(nwalkers, sizeof(XPoint));
+ if( (XPoint *)0 == walkers ) exit(1);
+
+ seeds = get_integer_resource("seeds", "Integer");
+ if( seeds < 1 ) seeds = 1;
+ if( seeds > 1000 ) seeds = 1000;
+
+ colorsloth = nwalkers*2/ncolors;
+ XSetForeground(dpy, draw_gc, colors[colorindex].pixel);
+
+ for( i = 0; i < seeds; i++ ) {
+ int x, y;
+ do {
+ x = random() % width;
+ y = random() % height;
+ } while( getdot(x, y) );
+
+ setdot((x-1), (y-1)); setdot(x, (y-1)); setdot((x+1), (y-1));
+ setdot((x-1), y ); setdot(x, y ); setdot((x+1), y );
+ setdot((x-1), (y+1)); setdot(x, (y+1)); setdot((x+1), (y+1));
+ XDrawPoint(dpy, window, draw_gc, x, y);
+ }
+
+ for( i = 0; i < nwalkers; i++ ) {
+ walkers[i].x = (random() % (width-2)) + 1;
+ walkers[i].y = (random() % (height-2)) + 1;
+ }
+}
+
+
+/* returns 2 bits of randomness (conserving calls to random()).
+ This speeds things up a little, but not a lot (5-10% or so.)
+ */
+static int
+rand_2(void)
+{
+ static int i = 0;
+ static int r = 0;
+ if (i != 0) {
+ i--;
+ } else {
+ i = 15;
+ r = random();
+ }
+
+ {
+ register int j = (r & 3);
+ r = r >> 2;
+ return j;
+ }
+}
+
+
+static void
+coral(Display *dpy, Window window)
+{
+ int delay2 = get_integer_resource ("delay2", "Integer");
+
+ int max_points = 200;
+ int npoints = 0;
+ XPoint *pointbuf = (XPoint *) calloc(sizeof(XPoint), max_points+2);
+ if (!pointbuf) exit(-1);
+
+ while( 1 ) {
+ int i;
+
+ for( i = 0; i < nwalkers; i++ ) {
+ int x = walkers[i].x;
+ int y = walkers[i].y;
+
+ if( getdot(x, y) ) {
+
+ Bool flush = False;
+ Bool color = False;
+
+ /* XDrawPoint(dpy, window, draw_gc, x, y); */
+ pointbuf[npoints].x = x;
+ pointbuf[npoints].y = y;
+ npoints++;
+
+ /* Mark the surrounding area as "sticky" */
+ setdot((x-1), (y-1)); setdot(x, (y-1)); setdot((x+1), (y-1));
+ setdot((x-1), y ); setdot((x+1), y );
+ setdot((x-1), (y+1)); setdot(x, (y+1)); setdot((x+1), (y+1));
+ nwalkers--;
+ walkers[i].x = walkers[nwalkers].x;
+ walkers[i].y = walkers[nwalkers].y;
+ if( 0 == (nwalkers%colorsloth) ) {
+ color = True;
+ }
+
+ if (flush || color || 0 == nwalkers || npoints >= max_points) {
+ XDrawPoints(dpy, window, draw_gc, pointbuf, npoints,
+ CoordModeOrigin);
+ npoints = 0;
+ XSync(dpy, True);
+ }
+
+ if (color) {
+ colorindex++;
+ if( colorindex == ncolors )
+ colorindex = 0;
+ XSetForeground(dpy, draw_gc, colors[colorindex].pixel);
+ }
+
+ if( 0 == nwalkers ) {
+ XSync(dpy, True);
+ free(pointbuf);
+ return;
+ }
+ } else {
+ /* move it a notch */
+ do {
+ switch(rand_2()) {
+ case 0:
+ if( 1 == x ) continue;
+ walkers[i].x--;
+ break;
+ case 1:
+ if( width-2 == x ) continue;
+ walkers[i].x++;
+ break;
+ case 2:
+ if( 1 == y ) continue;
+ walkers[i].y--;
+ break;
+ default: /* case 3: */
+ if( height-2 == y ) continue;
+ walkers[i].y++;
+ break;
+ /* default:
+ abort(); */
+ }
+ } while(0);
+ }
+ }
+
+ if (delay2 > 0) {
+ if (npoints > 0) {
+ XDrawPoints(dpy, window, draw_gc, pointbuf, npoints,
+ CoordModeOrigin);
+ npoints = 0;
+ XSync(dpy, True);
+ }
+ usleep(delay2);
+ }
+ }
+}
+
+char *progclass = "Coral";
+
+char *defaults[] = {
+ "Coral.background: black",
+ "Coral.foreground: white",
+ "*density: 25",
+ "*seeds: 20", /* too many for 640x480, too few for 1280x1024 */
+ "*delay: 5",
+ "*delay2: 1000",
+ 0
+};
+
+XrmOptionDescRec options[] = {
+ { "-density", ".density", XrmoptionSepArg, 0 },
+ { "-seeds", ".seeds", XrmoptionSepArg, 0 },
+ { "-delay", ".delay", XrmoptionSepArg, 0 },
+ { "-delay2", ".delay2", XrmoptionSepArg, 0 },
+ { 0, 0, 0, 0 }
+};
+
+void
+screenhack(dpy, window)
+Display *dpy;
+Window window;
+{
+ int delay = get_integer_resource ("delay", "Integer");
+
+ while( 1 ) {
+ init_coral(dpy, window);
+ coral(dpy, window);
+ if( delay ) sleep(delay);
+ }
+}
projects / xscreensaver / blobdiff