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xenocara/app/xlockmore/modes/discrete.c
matthieu 110b2a9207 Importing xlockmore 5.22
2006-11-26 11:07:42 +00:00

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/* -*- Mode: C; tab-width: 4 -*- */
/* discrete --- chaotic mappings */
#if !defined( lint ) && !defined( SABER )
static const char sccsid[] = "@(#)discrete.c 5.00 2000/11/01 xlockmore";
#endif
/*-
* Copyright (c) 1996 by Tim Auckland <tda10.geo@yahoo.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:
* 01-Nov-2000: Allocation checks
* 31-Jul-1997: Ported to xlockmore-4
* 08-Aug-1996: Adapted from hop.c Copyright (c) 1991 by Patrick J. Naughton.
*/
#ifdef STANDALONE
#define MODE_discrete
#define PROGCLASS "Discrete"
#define HACK_INIT init_discrete
#define HACK_DRAW draw_discrete
#define discrete_opts xlockmore_opts
#define DEFAULTS "*delay: 1000 \n" \
"*count: 4096 \n" \
"*cycles: 2500 \n" \
"*ncolors: 100 \n"
#define SMOOTH_COLORS
#include "xlockmore.h" /* in xscreensaver distribution */
#else /* STANDALONE */
#include "xlock.h" /* in xlockmore distribution */
#endif /* STANDALONE */
#ifdef MODE_discrete
ModeSpecOpt discrete_opts =
{0, (XrmOptionDescRec *) NULL, 0, (argtype *) NULL, (OptionStruct *) NULL};
#ifdef USE_MODULES
ModStruct discrete_description =
{"discrete", "init_discrete", "draw_discrete", "release_discrete",
"refresh_discrete", "init_discrete", (char *) 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 enum ftypes 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 = (discretestruct *) 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, xtemp, ytemp;
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 */
xtemp = x * x - y * y + hp->a;
ytemp = 2 * x * y + hp->b;
x = xtemp;
y = ytemp;
}
} 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(sizeof (XPoint) * MI_COUNT(mi));
/* if fails will check later */
}
/* Clear the background. */
MI_CLEARWINDOW(mi);
XSetForeground(MI_DISPLAY(mi), MI_GC(mi), MI_WHITE_PIXEL(mi));
hp->count = 0;
}
void
draw_discrete(ModeInfo * mi)
{
Display *dsp = MI_DISPLAY(mi);
Window win = MI_WINDOW(mi);
double oldj, oldi;
int count = MI_COUNT(mi);
int cycles = MI_CYCLES(mi);
int k;
XPoint *xp;
GC gc = MI_GC(mi);
discretestruct *hp;
if (discretes == NULL)
return;
hp = &discretes[MI_SCREEN(mi)];
if (hp->pointBuffer == NULL)
return;
k = count;
xp = hp->pointBuffer;
hp->inc++;
MI_IS_DRAWN(mi) = True;
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 < count / 4) {
hp->i = ((double) k / count) * 8 - 1;
hp->j = 1;
} else if (k < count / 2) {
hp->i = 1;
hp->j = 3 - ((double) k / count) * 8;
} else if (k < 3 * count / 4) {
hp->i = 5 - ((double) k / count) * 8;
hp->j = -1;
} else {
hp->i = -1;
hp->j = ((double) k / count) * 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);
if (hp->i < 0.00000001 && hp->i > -0.00000001)
hp->i = (hp->i > 0.0) ? 0.00000001 : -0.00000001;
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, count, CoordModeOrigin);
if (++hp->count > cycles) {
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) {
free(hp->pointBuffer);
/* hp->pointBuffer = NULL; */
}
}
free(discretes);
discretes = (discretestruct *) NULL;
}
}
void
refresh_discrete(ModeInfo * mi)
{
MI_CLEARWINDOW(mi);
}
#endif /* MODE_discrete */
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