+++ /dev/null
-/* -*- Mode: C; tab-width: 4 -*- */
-/* discrete --- chaotic mappings */
-
-#if !defined( lint ) && !defined( SABER )
-static const char sccsid[] = "@(#)discrete.c 4.10 98/04/24 xlockmore";
-
-#endif
-
-/*-
- * Copyright (c) 1996 by Tim Auckland <Tim.Auckland@Sun.COM>
- *
- * 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.
- *
- * "discrete" shows a number of fractals based on the "discrete map"
- * type of dynamical systems. They include a different way of looking
- * at the HOPALONG system, an inverse julia-set iteration, the "Standard
- * Map" and the "Bird in a Thornbush" fractal.
- *
- * Revision History:
- * 31-Jul-97: Ported to xlockmore-4
- * 08-Aug-96: Adapted from hop.c Copyright (c) 1991 by Patrick J. Naughton.
- */
-
-#ifdef STANDALONE
-# define PROGCLASS "Discrete"
-# define HACK_INIT init_discrete
-# define HACK_DRAW draw_discrete
-# define discrete_opts xlockmore_opts
-# define SMOOTH_COLORS
-# define BRIGHT_COLORS
-# define DEFAULTS "*delay: 1000 \n" \
- "*count: 4096 \n" \
- "*cycles: 2500 \n" \
- "*ncolors: 100 \n"
-
-# include "xlockmore.h" /* in xscreensaver distribution */
-# include "erase.h"
-
-#else /* STANDALONE */
-# include "xlock.h" /* in xlockmore distribution */
-#endif /* STANDALONE */
-
-ModeSpecOpt discrete_opts =
-{0, NULL, 0, NULL, NULL};
-
-#ifdef USE_MODULES
-ModStruct discrete_description =
-{"discrete", "init_discrete", "draw_discrete", "release_discrete",
- "refresh_discrete", "init_discrete", NULL, &discrete_opts,
- 1000, 4096, 2500, 1, 64, 1.0, "",
- "Shows various discrete maps", 0, NULL};
-
-#endif
-
-enum ftypes {
- SQRT, BIRDIE, STANDARD, TRIG, CUBIC, HENON, AILUJ, HSHOE, DELOG
-};
-
-/*#define TEST STANDARD */
-
-#define BIASES 18
-static int bias[BIASES] =
-{
- STANDARD, STANDARD, STANDARD, STANDARD,
- SQRT, SQRT, SQRT, SQRT,
- BIRDIE, BIRDIE, BIRDIE,
- AILUJ, AILUJ, AILUJ,
- TRIG, TRIG,
- CUBIC,
- HENON,
-};
-
-typedef struct {
- int maxx;
- int maxy; /* max of the screen */
- double a;
- double b;
- double c;
- double d;
- double e;
- double i;
- double j; /* discrete parameters */
- double ic;
- double jc;
- double is;
- double js;
- int inc;
- int pix;
- enum ftypes op;
- int count;
- XPoint *pointBuffer; /* pointer for XDrawPoints */
-} discretestruct;
-
-static discretestruct *discretes = NULL;
-
-void
-init_discrete(ModeInfo * mi)
-{
- double range;
- discretestruct *hp;
-
- if (discretes == NULL) {
- if ((discretes =
- (discretestruct *) calloc(MI_NUM_SCREENS(mi),
- sizeof (discretestruct))) == NULL)
- return;
- }
- hp = &discretes[MI_SCREEN(mi)];
-
-
- hp->maxx = MI_WIDTH(mi);
- hp->maxy = MI_HEIGHT(mi);
-#ifdef TEST
- hp->op = TEST;
-#else
- hp->op = bias[LRAND() % BIASES];
-#endif
- switch (hp->op) {
- case HSHOE:
- hp->ic = 0;
- hp->jc = 0;
- hp->is = hp->maxx / (4);
- hp->js = hp->maxy / (4);
- hp->a = 0.5;
- hp->b = 0.5;
- hp->c = 0.2;
- hp->d = -1.25;
- hp->e = 1;
- hp->i = hp->j = 0.0;
- break;
- case DELOG:
- hp->ic = 0.5;
- hp->jc = 0.3;
- hp->is = hp->maxx / 1.5;
- hp->js = hp->maxy / 1.5;
- hp->a = 2.176399;
- hp->i = hp->j = 0.01;
- break;
- case HENON:
- hp->jc = ((LRAND() / MAXRAND) * 2.0 - 1.0) * 0.4;
- hp->ic = 1.3 * (1 - (hp->jc * hp->jc) / (0.4 * 0.4));
- hp->is = hp->maxx;
- hp->js = hp->maxy * 1.5;
- hp->a = 1;
- hp->b = 1.4;
- hp->c = 0.3;
- hp->i = hp->j = 0;
- break;
- case SQRT:
- hp->ic = 0;
- hp->jc = 0;
- hp->is = 1;
- hp->js = 1;
- range = sqrt((double) hp->maxx * 2 * hp->maxx * 2 +
- (double) hp->maxy * 2 * hp->maxy * 2) /
- (10.0 + LRAND() % 10);
-
- hp->a = (LRAND() / MAXRAND) * range - range / 2.0;
- hp->b = (LRAND() / MAXRAND) * range - range / 2.0;
- hp->c = (LRAND() / MAXRAND) * range - range / 2.0;
- if (!(LRAND() % 2))
- hp->c = 0.0;
- hp->i = hp->j = 0.0;
- break;
- case STANDARD:
- hp->ic = M_PI;
- hp->jc = M_PI;
- hp->is = hp->maxx / (M_PI * 2);
- hp->js = hp->maxy / (M_PI * 2);
- hp->a = 0; /* decay */
- hp->b = (LRAND() / MAXRAND) * 2.0;
- hp->c = 0;
- hp->i = M_PI;
- hp->j = M_PI;
- break;
- case BIRDIE:
- hp->ic = 0;
- hp->jc = 0;
- hp->is = hp->maxx / 2;
- hp->js = hp->maxy / 2;
- hp->a = 1.99 + ((LRAND() / MAXRAND) * 2.0 - 1.0) * 0.2;
- hp->b = 0;
- hp->c = 0.8 + ((LRAND() / MAXRAND) * 2.0 - 1.0) * 0.1;
- hp->i = hp->j = 0;
- break;
- case TRIG:
- hp->a = 5;
- hp->b = 0.5 + ((LRAND() / MAXRAND) * 2.0 - 1.0) * 0.3;
- hp->ic = hp->a;
- hp->jc = 0;
- hp->is = hp->maxx / (hp->b * 20);
- hp->js = hp->maxy / (hp->b * 20);
- hp->i = hp->j = 0;
- break;
- case CUBIC:
- hp->a = 2.77;
- hp->b = 0.1 + ((LRAND() / MAXRAND) * 2.0 - 1.0) * 0.1;
- hp->ic = 0;
- hp->jc = 0;
- hp->is = hp->maxx / 4;
- hp->js = hp->maxy / 4;
- hp->i = hp->j = 0.1;
- break;
- case AILUJ:
- {
- int i;
- double x, y, xn, yn;
-
- hp->ic = 0;
- hp->jc = 0;
- hp->is = hp->maxx / 4;
- hp->js = hp->maxx / 4;
- do {
- hp->a = ((LRAND() / MAXRAND) * 2.0 - 1.0) * 1.5 - 0.5;
- hp->b = ((LRAND() / MAXRAND) * 2.0 - 1.0) * 1.5;
- x = y = 0;
-#define MAXITER 10
- for (i = 0; i < MAXITER && x * x + y * y < 13; i++) { /* 'Brot calc */
- xn = x * x - y * y + hp->a;
- yn = 2 * x * y + hp->b;
- x = xn;
- y = yn;
- }
- } while (i < MAXITER); /* wait for a connected set */
- hp->i = hp->j = 0.1;
- break;
- }
- }
- hp->pix = 0;
- hp->inc = 0;
-
- if (hp->pointBuffer == NULL)
- hp->pointBuffer = (XPoint *) malloc(MI_COUNT(mi) * sizeof (XPoint));
-
- /* Clear the background. */
- MI_CLEARWINDOW(mi);
-
- hp->count = 0;
-}
-
-
-void
-draw_discrete(ModeInfo * mi)
-{
- Display *dsp = MI_DISPLAY(mi);
- Window win = MI_WINDOW(mi);
- double oldj, oldi;
- int batchcount = MI_COUNT(mi);
- int cycles = MI_CYCLES(mi);
- int k;
- XPoint *xp;
- GC gc = MI_GC(mi);
- discretestruct *hp = &discretes[MI_SCREEN(mi)];
-
- k = batchcount;
- xp = hp->pointBuffer;
-
- hp->inc++;
-
- if (MI_NPIXELS(mi) > 2) {
- XSetForeground(dsp, gc, MI_PIXEL(mi, hp->pix));
- if (++hp->pix >= MI_NPIXELS(mi))
- hp->pix = 0;
- }
- while (k--) {
- oldj = hp->j;
- oldi = hp->i;
- switch (hp->op) {
- case HSHOE:
- {
- int i;
-
-#if 0
- if (!k) {
- XSetForeground(dsp, gc, MI_BLACK_PIXEL(mi));
- XFillRectangle(dsp, win, gc, 0, 0, hp->maxx, hp->maxy);
- XSetForeground(dsp, gc, MI_PIXEL(mi, hp->pix));
- } else
-#endif
-#define HD
-#ifdef HD
- if (k < batchcount / 4) {
- hp->i = ((double) k / batchcount) * 8 - 1;
- hp->j = 1;
- } else if (k < batchcount / 2) {
- hp->i = 1;
- hp->j = 3 - ((double) k / batchcount) * 8;
- } else if (k < 3 * batchcount / 4) {
- hp->i = 5 - ((double) k / batchcount) * 8;
- hp->j = -1;
- } else {
- hp->i = -1;
- hp->j = ((double) k / batchcount) * 8 - 7;
- }
- for (i = 1; i < (hp->inc % 15); i++) {
- oldj = hp->j;
- oldi = hp->i;
-#endif
- hp->i = (hp->a * oldi + hp->b) * oldj;
- hp->j = (hp->e - hp->d + hp->c * oldi) * oldj * oldj - hp->c * oldi + hp->d;
-#ifdef HD
- }
-#endif
- break;
- }
- case DELOG:
- hp->j = oldi;
- hp->i = hp->a * oldi * (1 - oldj);
- break;
- case HENON:
- hp->i = oldj + hp->a - hp->b * oldi * oldi;
- hp->j = hp->c * oldi;
- break;
- case SQRT:
- if (k) {
- hp->j = hp->a + hp->i;
- hp->i = -oldj + (hp->i < 0
- ? sqrt(fabs(hp->b * (hp->i - hp->c)))
- : -sqrt(fabs(hp->b * (hp->i - hp->c))));
- } else {
- static int s = 1;
-
- hp->i = s * hp->inc * hp->maxx / cycles / 2;
- hp->j = hp->a + hp->i;
- s = -s;
- }
- break;
- case STANDARD:
- if (k) {
- hp->j = (1 - hp->a) * oldj + hp->b * sin(oldi) + hp->a * hp->c;
- hp->j = fmod(hp->j + 2 * M_PI, 2 * M_PI);
- hp->i = oldi + hp->j;
- hp->i = fmod(hp->i + 2 * M_PI, 2 * M_PI);
- } else {
- static int s = 1;
-
- hp->j = M_PI + fmod(s * hp->inc * 2 * M_PI / (cycles - 0.5), M_PI);
- hp->i = M_PI;
- s = -s;
- }
- break;
- case BIRDIE:
- hp->j = oldi;
- hp->i = (1 - hp->c) * cos(M_PI * hp->a * oldj) + hp->c * hp->b;
- hp->b = oldj;
- break;
- case TRIG:
- {
- double r2 = oldi * oldi + oldj * oldj;
-
- hp->i = hp->a + hp->b * (oldi * cos(r2) - oldj * sin(r2));
- hp->j = hp->b * (oldj * cos(r2) + oldi * sin(r2));
- }
- break;
- case CUBIC:
- hp->i = oldj;
- hp->j = hp->a * oldj - oldj * oldj * oldj - hp->b * oldi;
- break;
- case AILUJ:
- hp->i = ((LRAND() < MAXRAND / 2) ? -1 : 1) *
- sqrt(((oldi - hp->a) +
- sqrt((oldi - hp->a) * (oldi - hp->a) + (oldj - hp->b) * (oldj - hp->b))) / 2);
- hp->j = (oldj - hp->b) / (2 * hp->i);
- break;
- }
- xp->x = hp->maxx / 2 + (int) ((hp->i - hp->ic) * hp->is);
- xp->y = hp->maxy / 2 - (int) ((hp->j - hp->jc) * hp->js);
- xp++;
- }
- XDrawPoints(dsp, win, gc, hp->pointBuffer, batchcount, CoordModeOrigin);
- if (++hp->count > cycles) {
-#ifdef STANDALONE
- erase_full_window(MI_DISPLAY(mi), MI_WINDOW(mi));
-#endif /* STANDALONE */
- init_discrete(mi);
- }
-}
-
-void
-release_discrete(ModeInfo * mi)
-{
- if (discretes != NULL) {
- int screen;
-
- for (screen = 0; screen < MI_NUM_SCREENS(mi); screen++) {
- discretestruct *hp = &discretes[screen];
-
- if (hp->pointBuffer != NULL)
- (void) free((void *) hp->pointBuffer);
- }
- (void) free((void *) discretes);
- discretes = NULL;
- }
-}
-
-void
-refresh_discrete(ModeInfo * mi)
-{
- MI_CLEARWINDOW(mi);
-}
projects / xscreensaver / blobdiff