/* -*- Mode: C; tab-width: 4 -*- */
/* thornbird --- continuously varying Thornbird set */
#if 0
static const char sccsid[] = "@(#)thornbird.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.
*
* "thornbird" shows a view of the "Bird in a Thornbush" fractal,
* continuously varying the three free parameters.
*
* Revision History:
* 01-Nov-2000: Allocation checks
* 04-Jun-1999: 3D tumble added by Tim Auckland
* 31-Jul-1997: Adapted from discrete.c Copyright (c) 1996 by Tim Auckland
*/
#ifdef STANDALONE
# define MODE_thornbird
#define DEFAULTS "*delay: 10000 \n" \
"*count: 100 \n" \
"*cycles: 400 \n" \
"*ncolors: 64 \n" \
"*fpsSolid: true \n" \
"*ignoreRotation: True \n" \
"*lowrez: True \n" \
# define BRIGHT_COLORS
# define release_thornbird 0
# define reshape_thornbird 0
# define thornbird_handle_event 0
# include "xlockmore.h" /* in xscreensaver distribution */
#else /* STANDALONE */
# include "xlock.h" /* in xlockmore distribution */
#endif /* STANDALONE */
#ifdef MODE_thornbird
ENTRYPOINT ModeSpecOpt thornbird_opts =
{0, (XrmOptionDescRec *) NULL, 0, (argtype *) NULL, (OptionStruct *) NULL};
#ifdef USE_MODULES
ModStruct thornbird_description =
{"thornbird", "init_thornbird", "draw_thornbird", (char *) NULL,
"refresh_thornbird", "init_thornbird", "free_thornbird", þbird_opts,
1000, 800, 16, 1, 64, 1.0, "",
"Shows an animated Bird in a Thorn Bush fractal map", 0, NULL};
#endif
#define balance_rand(v) ((LRAND()/MAXRAND*(v))-((v)/2)) /* random around 0 */
typedef struct {
int maxx;
int maxy; /* max of the screen */
double a;
double b;
double c;
double d;
double e;
double i;
double j; /* thornbird parameters */
struct {
double f1;
double f2;
} liss;
struct {
double theta;
double dtheta;
double phi;
double dphi;
} tumble;
int inc;
int pix;
int count;
int nbuffers;
XPoint **pointBuffer; /* pointer for XDrawPoints */
} thornbirdstruct;
static thornbirdstruct *thornbirds = (thornbirdstruct *) NULL;
ENTRYPOINT void
free_thornbird(ModeInfo * mi)
{
thornbirdstruct *hp = þbirds[MI_SCREEN(mi)];
if (hp->pointBuffer != NULL) {
int buffer;
for (buffer = 0; buffer < hp->nbuffers; buffer++)
if (hp->pointBuffer[buffer] != NULL)
(void) free((void *) hp->pointBuffer[buffer]);
(void) free((void *) hp->pointBuffer);
hp->pointBuffer = (XPoint **) NULL;
}
}
ENTRYPOINT void
init_thornbird (ModeInfo * mi)
{
thornbirdstruct *hp;
MI_INIT (mi, thornbirds);
hp = þbirds[MI_SCREEN(mi)];
hp->maxx = MI_WIDTH(mi);
hp->maxy = MI_HEIGHT(mi);
hp->b = 0.1;
hp->i = hp->j = 0.1;
hp->pix = 0;
hp->inc = 0;
hp->nbuffers = MI_CYCLES(mi);
if (hp->pointBuffer == NULL)
if ((hp->pointBuffer = (XPoint **) calloc(MI_CYCLES(mi),
sizeof (XPoint *))) == NULL) {
free_thornbird(mi);
return;
}
if (hp->pointBuffer[0] == NULL)
if ((hp->pointBuffer[0] = (XPoint *) malloc(MI_COUNT(mi) *
sizeof (XPoint))) == NULL) {
free_thornbird(mi);
return;
}
/* select frequencies for parameter variation */
hp->liss.f1 = LRAND() % 5000;
hp->liss.f2 = LRAND() % 2000;
/* choose random 3D tumbling */
hp->tumble.theta = 0;
hp->tumble.phi = 0;
hp->tumble.dtheta = balance_rand(0.001);
hp->tumble.dphi = balance_rand(0.005);
/* Clear the background. */
MI_CLEARWINDOW(mi);
hp->count = 0;
}
ENTRYPOINT void
draw_thornbird(ModeInfo * mi)
{
Display *dsp = MI_DISPLAY(mi);
Window win = MI_WINDOW(mi);
double oldj, oldi;
int batchcount = MI_COUNT(mi);
int k;
XPoint *xp;
GC gc = MI_GC(mi);
int erase;
int current;
double sint, cost, sinp, cosp;
thornbirdstruct *hp;
if (thornbirds == NULL)
return;
hp = þbirds[MI_SCREEN(mi)];
if (hp->pointBuffer == NULL)
return;
erase = (hp->inc + 1) % MI_CYCLES(mi);
current = hp->inc % MI_CYCLES(mi);
k = batchcount;
xp = hp->pointBuffer[current];
/* vary papameters */
hp->a = 1.99 + (0.4 * sin(hp->inc / hp->liss.f1) +
0.05 * cos(hp->inc / hp->liss.f2));
hp->c = 0.80 + (0.15 * cos(hp->inc / hp->liss.f1) +
0.05 * sin(hp->inc / hp->liss.f2));
/* vary view */
hp->tumble.theta += hp->tumble.dtheta;
hp->tumble.phi += hp->tumble.dphi;
sint = sin(hp->tumble.theta);
cost = cos(hp->tumble.theta);
sinp = sin(hp->tumble.phi);
cosp = cos(hp->tumble.phi);
while (k--) {
oldj = hp->j;
oldi = hp->i;
hp->j = oldi;
hp->i = (1 - hp->c) * cos(M_PI * hp->a * oldj) + hp->c * hp->b;
hp->b = oldj;
xp->x = (short)
(hp->maxx / 2 * (1
+ sint*hp->j + cost*cosp*hp->i - cost*sinp*hp->b));
xp->y = (short)
(hp->maxy / 2 * (1
- cost*hp->j + sint*cosp*hp->i - sint*sinp*hp->b));
xp++;
}
MI_IS_DRAWN(mi) = True;
if (MI_COUNT(mi) < 1) MI_COUNT(mi) = 1;
if (hp->pointBuffer[erase] == NULL) {
if ((hp->pointBuffer[erase] = (XPoint *) malloc(MI_COUNT(mi) *
sizeof (XPoint))) == NULL) {
free_thornbird(mi);
return;
}
} else {
XSetForeground(dsp, gc, MI_BLACK_PIXEL(mi));
XDrawPoints(dsp, win, gc, hp->pointBuffer[erase],
batchcount, CoordModeOrigin);
}
if (MI_NPIXELS(mi) > 2) {
XSetForeground(dsp, gc, MI_PIXEL(mi, hp->pix));
#if 0
if (erase == 0) /* change colours after "cycles" cycles */
#else
if (!((hp->inc + 1) % (1 + (MI_CYCLES(mi) / 3)))) /* jwz: sooner */
#endif
if (++hp->pix >= MI_NPIXELS(mi))
hp->pix = 0;
} else
XSetForeground(dsp, gc, MI_WHITE_PIXEL(mi));
XDrawPoints(dsp, win, gc, hp->pointBuffer[current],
batchcount, CoordModeOrigin);
hp->inc++;
}
#ifndef STANDALONE
ENTRYPOINT void
refresh_thornbird (ModeInfo * mi)
{
MI_CLEARWINDOW(mi);
}
#endif
XSCREENSAVER_MODULE ("Thornbird", thornbird)
#endif /* MODE_thornbird */
