--- /dev/null
+/* -*- Mode: C; tab-width: 4 -*-
+ * slip --- lots of blits.
+ */
+#if !defined( lint ) && !defined( SABER )
+static const char sccsid[] = "@(#)slip.c 4.00 97/01/01 xlockmore";
+#endif
+
+/* Copyright (c) 1992 by Scott Draves (spot@cs.cmu.edu)
+ *
+ * Permission to use, copy, modify, and distribute this software and its
+ * documentation for any purpose and without fee is hereby granted,
+ * provided that the above copyright notice appear in all copies and that
+ * both that copyright notice and this permission notice appear in
+ * supporting documentation.
+ *
+ * This file is provided AS IS with no warranties of any kind. The author
+ * shall have no liability with respect to the infringement of copyrights,
+ * trade secrets or any patents by this file or any part thereof. In no
+ * event will the author be liable for any lost revenue or profits or
+ * other special, indirect and consequential damages.
+ *
+ * Revision History:
+ * 12-May-97: jwz@jwz.org: turned into a standalone program.
+ * 01-Dec-95: Patched for VMS <joukj@alpha.chem.uva.nl>.
+ */
+
+#ifdef STANDALONE
+# define PROGCLASS "Slip"
+# define HACK_INIT init_slip
+# define HACK_DRAW draw_slip
+# define slip_opts xlockmore_opts
+# define DEFAULTS "*count: 35 \n" \
+ "*cycles: 50 \n" \
+ "*delay: 50000 \n" \
+ "*ncolors: 200 \n"
+# include "xlockmore.h" /* from the xscreensaver distribution */
+#else /* !STANDALONE */
+# include "xlock.h" /* from the xlockmore distribution */
+#endif /* !STANDALONE */
+
+ModeSpecOpt slip_opts = {
+ 0, NULL, 0, NULL, NULL };
+
+typedef struct {
+ int width, height;
+ int nblits_remaining;
+ int blit_width, blit_height;
+ int mode;
+ int first_time;
+ int backwards;
+} slipstruct;
+static slipstruct *slips = NULL;
+
+static short
+halfrandom(int mv)
+{
+ static short lasthalf = 0;
+ unsigned long r;
+
+ if (lasthalf) {
+ r = lasthalf;
+ lasthalf = 0;
+ } else {
+ r = LRAND();
+ lasthalf = r >> 16;
+ }
+ return r % mv;
+}
+
+static int
+erandom(int mv)
+{
+ static int stage = 0;
+ static unsigned long r;
+ int res;
+
+ if (0 == stage) {
+ r = LRAND();
+ stage = 7;
+ }
+ res = r & 0xf;
+ r = r >> 4;
+ stage--;
+ if (res & 8)
+ return res & mv;
+ else
+ return -(res & mv);
+}
+
+static void
+prepare_screen(ModeInfo * mi, slipstruct * s)
+{
+
+ Display *display = MI_DISPLAY(mi);
+ GC gc = MI_GC(mi);
+ int i, n, w = s->width / 20;
+ int not_solid = halfrandom(10);
+
+#ifdef STANDALONE /* jwz -- sometimes hack the desktop image! */
+ if (halfrandom(2) == 0)
+ {
+ grab_screen_image(DefaultScreenOfDisplay (MI_DISPLAY(mi)),
+ MI_WINDOW(mi));
+ return;
+ }
+#endif
+
+ s->backwards = LRAND() & 1; /* jwz: go the other way sometimes */
+
+ if (s->first_time || (0 == halfrandom(10))) {
+ XClearWindow(display, MI_WINDOW(mi));
+ n = 300;
+ } else {
+ if (halfrandom(5))
+ return;
+ if (halfrandom(5))
+ n = 100;
+ else
+ n = 2000;
+ }
+
+ if (MI_NPIXELS(mi) > 2)
+ XSetForeground(display, gc, MI_PIXEL(mi, halfrandom(MI_NPIXELS(mi))));
+ else if (halfrandom(2))
+ XSetForeground(display, gc, MI_WIN_WHITE_PIXEL(mi));
+ else
+ XSetForeground(display, gc, MI_WIN_BLACK_PIXEL(mi));
+
+ for (i = 0; i < n; i++) {
+ int ww = ((w/2) + halfrandom(w));
+ if (not_solid)
+ if (MI_NPIXELS(mi) > 2)
+ XSetForeground(display, gc, MI_PIXEL(mi, halfrandom(MI_NPIXELS(mi))));
+ else if (halfrandom(2))
+ XSetForeground(display, gc, MI_WIN_WHITE_PIXEL(mi));
+ else
+ XSetForeground(display, gc, MI_WIN_BLACK_PIXEL(mi));
+ XFillRectangle(display, MI_WINDOW(mi), gc,
+ halfrandom(s->width - ww),
+ halfrandom(s->height - ww),
+ ww, ww);
+ }
+ s->first_time = 0;
+}
+
+static int
+quantize(double d)
+{
+ int i = (int) floor(d);
+ double f = d - i;
+
+ if ((LRAND() & 0xff) < f * 0xff)
+ i++;
+ return i;
+}
+
+void
+init_slip(ModeInfo * mi)
+{
+ slipstruct *sp;
+
+ if (slips == NULL) {
+ if ((slips = (slipstruct *) calloc(MI_NUM_SCREENS(mi),
+ sizeof (slipstruct))) == NULL)
+ return;
+ }
+ sp = &slips[MI_SCREEN(mi)];
+
+ sp->width = MI_WIN_WIDTH(mi);
+ sp->height = MI_WIN_HEIGHT(mi);
+
+ sp->blit_width = sp->width / 25;
+ sp->blit_height = sp->height / 25;
+ sp->nblits_remaining = 0;
+ sp->mode = 0;
+ sp->first_time = 1;
+
+ /* no "NoExpose" events from XCopyArea wanted */
+ XSetGraphicsExposures(MI_DISPLAY(mi), MI_GC(mi), False);
+}
+
+void
+draw_slip(ModeInfo * mi)
+{
+ Display *display = MI_DISPLAY(mi);
+ Window window = MI_WINDOW(mi);
+ GC gc = MI_GC(mi);
+ slipstruct *s = &slips[MI_SCREEN(mi)];
+ int timer;
+
+ timer = MI_BATCHCOUNT(mi) * MI_CYCLES(mi);
+
+ while (timer--) {
+ int xi = halfrandom(s->width - s->blit_width);
+ int yi = halfrandom(s->height - s->blit_height);
+ double x, y, dx = 0, dy = 0, t, s1, s2;
+
+ if (0 == s->nblits_remaining--) {
+ static int lut[] =
+ {0, 0, 0, 1, 1, 1, 2};
+
+ prepare_screen(mi, s);
+ s->nblits_remaining = MI_BATCHCOUNT(mi) *
+ (2000 + halfrandom(1000) + halfrandom(1000));
+ if (s->mode == 2)
+ s->mode = halfrandom(2);
+ else
+ s->mode = lut[halfrandom(7)];
+ }
+ x = (2 * xi + s->blit_width) / (double) s->width - 1;
+ y = (2 * yi + s->blit_height) / (double) s->height - 1;
+
+ /* (x,y) is in biunit square */
+ switch (s->mode) {
+ case 0: /* rotor */
+ dx = x;
+ dy = y;
+
+ if (dy < 0) {
+ dy += 0.04;
+ if (dy > 0)
+ dy = 0.00;
+ }
+ if (dy > 0) {
+ dy -= 0.04;
+ if (dy < 0)
+ dy = 0.00;
+ }
+ t = dx * dx + dy * dy + 1e-10;
+ s1 = 2 * dx * dx / t - 1;
+ s2 = 2 * dx * dy / t;
+ dx = s1 * 5;
+ dy = s2 * 5;
+ if (s->backwards) { /* jwz: go the other way sometimes */
+ dx = -dx;
+ dy = -dy;
+ }
+ break;
+ case 1: /* shuffle */
+ dx = erandom(3);
+ dy = erandom(3);
+ break;
+ case 2: /* explode */
+ dx = x * 3;
+ dy = y * 3;
+ break;
+ }
+ {
+ int qx = xi + quantize(dx), qy = yi + quantize(dy);
+ int wrap;
+
+ if (qx < 0 || qy < 0 ||
+ qx >= s->width - s->blit_width ||
+ qy >= s->height - s->blit_height)
+ continue;
+
+ XCopyArea(display, window, window, gc, xi, yi,
+ s->blit_width, s->blit_height,
+ qx, qy);
+
+ switch (s->mode) {
+ case 0:
+ /* wrap */
+ wrap = s->width - (2 * s->blit_width);
+ if (qx > wrap)
+ XCopyArea(display, window, window, gc, qx, qy,
+ s->blit_width, s->blit_height,
+ qx - wrap, qy);
+
+ if (qx < 2 * s->blit_width)
+ XCopyArea(display, window, window, gc, qx, qy,
+ s->blit_width, s->blit_height,
+ qx + wrap, qy);
+
+ wrap = s->height - (2 * s->blit_height);
+ if (qy > wrap)
+ XCopyArea(display, window, window, gc, qx, qy,
+ s->blit_width, s->blit_height,
+ qx, qy - wrap);
+
+ if (qy < 2 * s->blit_height)
+ XCopyArea(display, window, window, gc, qx, qy,
+ s->blit_width, s->blit_height,
+ qx, qy + wrap);
+ break;
+ case 1:
+ case 2:
+ break;
+ }
+ }
+ }
+}
+
+void
+release_slip(ModeInfo * mi)
+{
+ if (slips != NULL) {
+ (void) free((void *) slips);
+ slips = NULL;
+ }
+}
projects / xscreensaver / blobdiff