/* -*- 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 . */ #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 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; } }