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

472 lines
12 KiB
C
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/* -*- Mode: C; tab-width: 4 -*- */
/* strange --- strange attractors */
#if !defined( lint ) && !defined( SABER )
static const char sccsid[] = "@(#)strange.c 5.00 2000/11/01 xlockmore";
#endif
/*-
* Copyright (c) 1997 by Massimino Pascal <Pascal.Massimon@ens.fr>
*
* 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:
* 22-Dec-2004: TDA: Replace Gauss_Rand with a real Gaussian.
* 01-Nov-2000: Allocation checks
* 10-May-1997: jwz@jwz.org: turned into a standalone program.
* Made it render into an offscreen bitmap and then copy
* that onto the screen, to reduce flicker.
*
* strange attractors are not so hard to find...
*/
#ifdef STANDALONE
#define MODE_strange
#define PROGCLASS "Strange"
#define HACK_INIT init_strange
#define HACK_DRAW draw_strange
#define strange_opts xlockmore_opts
#define DEFAULTS "*delay: 1000 \n" \
"*ncolors: 100 \n"
#define SMOOTH_COLORS
#include "xlockmore.h" /* from the xscreensaver distribution */
#else /* !STANDALONE */
#include "xlock.h" /* from the xlockmore distribution */
#endif /* !STANDALONE */
#ifdef MODE_strange
ModeSpecOpt strange_opts =
{0, (XrmOptionDescRec *) NULL, 0, (argtype *) NULL, (OptionStruct *) NULL};
#ifdef USE_MODULES
ModStruct strange_description =
{"strange", "init_strange", "draw_strange", "release_strange",
"init_strange", "init_strange", (char *) NULL, &strange_opts,
1000, 1, 1, 1, 64, 1.0, "",
"Shows strange attractors", 0, NULL};
#endif
typedef float DBL;
typedef int PRM;
#define UNIT (1<<12)
#define UNIT2 (1<<14)
/* #define UNIT2 (3140*UNIT/1000) */
#define SKIP_FIRST 100
#define MAX_POINTS 5500
#define DBL_To_PRM(x) (PRM)( (DBL)(UNIT)*(x) )
#define DO_FOLD(a) (a)<0 ? -A->Fold[ (-(a))&(UNIT2-1) ] : A->Fold[ (a)&(UNIT2-1) ]
#if 0
#define DO_FOLD(a) (a)<-UNIT2 ? -A->Fold[(-(a))%UNIT2] : (a)<0 ? -A->Fold[ -(a) ] :\
(a)>UNIT2 ? A->Fold[ (a)%UNIT2 ] : A->Fold[ (a) ]
#define DO_FOLD(a) DBL_To_PRM( sin( (DBL)(a)/UNIT ) )
#define DO_FOLD(a) (a)<0 ? DBL_To_PRM( exp( 16.0*(a)/UNIT2 ) )-1.0 : \
DBL_To_PRM( 1.0-exp( -16.0*(a)/UNIT2 ) )
#endif
/******************************************************************/
#define MAX_PRM 3*5
typedef struct _ATTRACTOR {
DBL Prm1[MAX_PRM], Prm2[MAX_PRM];
PRM Prm[MAX_PRM], *Fold;
void (*Iterate) (struct _ATTRACTOR *, PRM, PRM, PRM *, PRM *);
XPoint *Buffer1, *Buffer2;
int Cur_Pt, Max_Pt;
int Col, Count, Speed;
int Width, Height;
Pixmap dbuf; /* jwz */
GC dbuf_gc;
} ATTRACTOR;
static ATTRACTOR *Root = (ATTRACTOR *) NULL;
static DBL Amp_Prm[MAX_PRM] =
{
1.0, 3.5, 3.5, 2.5, 4.7,
1.0, 3.5, 3.6, 2.5, 4.7,
1.0, 1.5, 2.2, 2.1, 3.5
};
static DBL Mid_Prm[MAX_PRM] =
{
0.0, 1.5, 0.0, .5, 1.5,
0.0, 1.5, 0.0, .5, 1.5,
0.0, 1.5, -1.0, -.5, 2.5,
};
#if 0
static DBL
Gauss_Rand(DBL c, DBL A, DBL S)
{
DBL y;
y = (DBL) LRAND() / MAXRAND;
y = A * (1.0 - exp(-y * y * S)) / (1.0 - exp(-S));
if (NRAND(2))
return (c + y);
else
return (c - y);
}
#else
/* I don't know that it makes a difference, but this one actually *is*
a Gaussian. [TDA] */
/* Generate Gaussian random number: mean c, "amplitude" A (actually
A is 3*standard deviation). 'S' is unused. */
/* Note this generates a pair of gaussian variables, so it saves one
to give out next time it's called */
static double
Gauss_Rand(DBL c, DBL A, DBL S)
{
static double d;
static Bool ready = 0;
if(ready) {
ready = 0;
return c + A/3 * d;
} else {
double x, y, w;
do {
x = 2.0 * (double)LRAND() / MAXRAND - 1.0;
y = 2.0 * (double)LRAND() / MAXRAND - 1.0;
w = x*x + y*y;
} while(w >= 1.0);
w = sqrt((-2 * log(w))/w);
ready = 1;
d = x * w;
return c + A/3 * y * w;
}
}
#endif
static void
Random_Prm(DBL * Prm)
{
int i;
for (i = 0; i < MAX_PRM; ++i)
Prm[i] = Gauss_Rand(Mid_Prm[i], Amp_Prm[i], 4.0);
}
/***************************************************************/
/* 2 examples of non-linear map */
static void
Iterate_X2(ATTRACTOR * A, PRM x, PRM y, PRM * xo, PRM * yo)
{
PRM xx, yy, xy, x2y, y2x, Tmp;
xx = (x * x) / UNIT;
x2y = (xx * y) / UNIT;
yy = (y * y) / UNIT;
y2x = (yy * x) / UNIT;
xy = (x * y) / UNIT;
Tmp = A->Prm[1] * xx + A->Prm[2] * xy + A->Prm[3] * yy + A->Prm[4] * x2y;
Tmp = A->Prm[0] - y + (Tmp / UNIT);
*xo = DO_FOLD(Tmp);
Tmp = A->Prm[6] * xx + A->Prm[7] * xy + A->Prm[8] * yy + A->Prm[9] * y2x;
Tmp = A->Prm[5] + x + (Tmp / UNIT);
*yo = DO_FOLD(Tmp);
}
static void
Iterate_X3(ATTRACTOR * A, PRM x, PRM y, PRM * xo, PRM * yo)
{
PRM xx, yy, xy, x2y, y2x, Tmp_x, Tmp_y, Tmp_z;
xx = (x * x) / UNIT;
x2y = (xx * y) / UNIT;
yy = (y * y) / UNIT;
y2x = (yy * x) / UNIT;
xy = (x * y) / UNIT;
Tmp_x = A->Prm[1] * xx + A->Prm[2] * xy + A->Prm[3] * yy + A->Prm[4] * x2y;
Tmp_x = A->Prm[0] - y + (Tmp_x / UNIT);
Tmp_x = DO_FOLD(Tmp_x);
Tmp_y = A->Prm[6] * xx + A->Prm[7] * xy + A->Prm[8] * yy + A->Prm[9] * y2x;
Tmp_y = A->Prm[5] + x + (Tmp_y / UNIT);
Tmp_y = DO_FOLD(Tmp_y);
Tmp_z = A->Prm[11] * xx + A->Prm[12] * xy + A->Prm[13] * yy + A->Prm[14] * y2x;
Tmp_z = A->Prm[10] + x + (Tmp_z / UNIT);
Tmp_z = UNIT + Tmp_z * Tmp_z / UNIT;
*xo = (Tmp_x * UNIT) / Tmp_z;
*yo = (Tmp_y * UNIT) / Tmp_z;
}
static void (*Funcs[2]) (ATTRACTOR *, PRM, PRM, PRM *, PRM *) = {
Iterate_X2, Iterate_X3
};
/***************************************************************/
static void
free_strange(Display *display, ATTRACTOR *A)
{
if (A->Buffer1 != NULL) {
free(A->Buffer1);
A->Buffer1 = (XPoint *) NULL;
}
if (A->Buffer2 != NULL) {
free(A->Buffer2);
A->Buffer2 = (XPoint *) NULL;
}
if (A->dbuf) {
XFreePixmap(display, A->dbuf);
A->dbuf = None;
}
if (A->dbuf_gc) {
XFreeGC(display, A->dbuf_gc);
A->dbuf_gc = None;
}
if (A->Fold != NULL) {
free(A->Fold);
A->Fold = (PRM *) NULL;
}
}
void
draw_strange(ModeInfo * mi)
{
int i, j, n, Cur_Pt;
PRM x, y, xo, yo;
DBL u;
XPoint *Buf;
Display *display = MI_DISPLAY(mi);
Window window = MI_WINDOW(mi);
GC gc = MI_GC(mi);
DBL Lx, Ly;
void (*Iterate) (ATTRACTOR *, PRM, PRM, PRM *, PRM *);
PRM xmin, xmax, ymin, ymax;
ATTRACTOR *A;
if (Root == NULL)
return;
A = &Root[MI_SCREEN(mi)];
if (A->Fold == NULL)
return;
Cur_Pt = A->Cur_Pt;
Iterate = A->Iterate;
u = (DBL) (A->Count) / 1000.0;
for (j = MAX_PRM - 1; j >= 0; --j)
A->Prm[j] = DBL_To_PRM((1.0 - u) * A->Prm1[j] + u * A->Prm2[j]);
x = y = DBL_To_PRM(.0);
for (n = SKIP_FIRST; n; --n) {
(*Iterate) (A, x, y, &xo, &yo);
x = xo + NRAND(8) - 4;
y = yo + NRAND(8) - 4;
}
xmax = 0;
xmin = UNIT * 4;
ymax = 0;
ymin = UNIT * 4;
A->Cur_Pt = 0;
Buf = A->Buffer2;
Lx = (DBL) A->Width / UNIT / 2.2;
Ly = (DBL) A->Height / UNIT / 2.2;
for (n = A->Max_Pt; n; --n) {
(*Iterate) (A, x, y, &xo, &yo);
Buf->x = (int) (Lx * (x + DBL_To_PRM(1.1)));
Buf->y = (int) (Ly * (DBL_To_PRM(1.1) - y));
/* (void) fprintf( stderr, "X,Y: %d %d ", Buf->x, Buf->y ); */
Buf++;
A->Cur_Pt++;
if (xo > xmax)
xmax = xo;
else if (xo < xmin)
xmin = xo;
if (yo > ymax)
ymax = yo;
else if (yo < ymin)
ymin = yo;
x = xo + NRAND(8) - 4;
y = yo + NRAND(8) - 4;
}
MI_IS_DRAWN(mi) = True;
XSetForeground(display, gc, MI_BLACK_PIXEL(mi));
if (A->dbuf != None) { /* jwz */
XSetForeground(display, A->dbuf_gc, 0);
/* XDrawPoints(display, A->dbuf, A->dbuf_gc, A->Buffer1,
Cur_Pt,CoordModeOrigin); */
XFillRectangle(display, A->dbuf, A->dbuf_gc, 0, 0, A->Width, A->Height);
} else
XDrawPoints(display, window, gc, A->Buffer1, Cur_Pt, CoordModeOrigin);
if (MI_NPIXELS(mi) < 2)
XSetForeground(display, gc, MI_WHITE_PIXEL(mi));
else
XSetForeground(display, gc, MI_PIXEL(mi, A->Col % MI_NPIXELS(mi)));
if (A->dbuf != None) {
XSetForeground(display, A->dbuf_gc, 1);
XDrawPoints(display, A->dbuf, A->dbuf_gc, A->Buffer2, A->Cur_Pt,
CoordModeOrigin);
XCopyPlane(display, A->dbuf, window, gc, 0, 0, A->Width, A->Height, 0, 0, 1);
} else
XDrawPoints(display, window, gc, A->Buffer2, A->Cur_Pt, CoordModeOrigin);
Buf = A->Buffer1;
A->Buffer1 = A->Buffer2;
A->Buffer2 = Buf;
if ((xmax - xmin < DBL_To_PRM(.2)) && (ymax - ymin < DBL_To_PRM(.2)))
A->Count += 4 * A->Speed;
else
A->Count += A->Speed;
if (A->Count >= 1000) {
for (i = MAX_PRM - 1; i >= 0; --i)
A->Prm1[i] = A->Prm2[i];
Random_Prm(A->Prm2);
A->Count = 0;
}
A->Col++;
}
/***************************************************************/
void
init_strange(ModeInfo * mi)
{
Display *display = MI_DISPLAY(mi);
Window window = MI_WINDOW(mi);
GC gc = MI_GC(mi);
ATTRACTOR *Attractor;
if (Root == NULL) {
if ((Root = (ATTRACTOR *) calloc(MI_NUM_SCREENS(mi),
sizeof (ATTRACTOR))) == NULL)
return;
}
Attractor = &Root[MI_SCREEN(mi)];
if (Attractor->Fold == NULL) {
int i;
if ((Attractor->Fold = (PRM *) calloc(UNIT2 + 1,
sizeof (PRM))) == NULL) {
free_strange(display, Attractor);
return;
}
for (i = 0; i <= UNIT2; ++i) {
DBL x;
/* x = ( DBL )(i)/UNIT2; */
/* x = sin( M_PI/2.0*x ); */
/* x = sqrt( x ); */
/* x = x*x; */
/* x = x*(1.0-x)*4.0; */
x = (DBL) (i) / UNIT;
x = sin(x);
Attractor->Fold[i] = DBL_To_PRM(x);
}
}
if (Attractor->Buffer1 == NULL)
if ((Attractor->Buffer1 = (XPoint *) calloc(MAX_POINTS,
sizeof (XPoint))) == NULL) {
free_strange(display, Attractor);
return;
}
if (Attractor->Buffer2 == NULL)
if ((Attractor->Buffer2 = (XPoint *) calloc(MAX_POINTS,
sizeof (XPoint))) == NULL) {
free_strange(display, Attractor);
return;
}
Attractor->Max_Pt = MAX_POINTS;
Attractor->Width = MI_WIDTH(mi);
Attractor->Height = MI_HEIGHT(mi);
Attractor->Cur_Pt = 0;
Attractor->Count = 0;
Attractor->Col = NRAND(MI_NPIXELS(mi));
Attractor->Speed = 4;
Attractor->Iterate = Funcs[NRAND(2)];
Random_Prm(Attractor->Prm1);
Random_Prm(Attractor->Prm2);
#ifndef NO_DBUF
if (Attractor->dbuf != None)
XFreePixmap(display, Attractor->dbuf);
Attractor->dbuf = XCreatePixmap(display, window,
Attractor->Width, Attractor->Height, 1);
/* Allocation checked */
if (Attractor->dbuf != None) {
XGCValues gcv;
gcv.foreground = 0;
gcv.background = 0;
gcv.graphics_exposures = False;
gcv.function = GXcopy;
if (Attractor->dbuf_gc != None)
XFreeGC(display, Attractor->dbuf_gc);
if ((Attractor->dbuf_gc = XCreateGC(display, Attractor->dbuf,
GCForeground | GCBackground | GCGraphicsExposures | GCFunction,
&gcv)) == None) {
XFreePixmap(display, Attractor->dbuf);
Attractor->dbuf = None;
} else {
XFillRectangle(display, Attractor->dbuf, Attractor->dbuf_gc,
0, 0, Attractor->Width, Attractor->Height);
XSetBackground(display, gc, MI_BLACK_PIXEL(mi));
XSetFunction(display, gc, GXcopy);
}
}
#endif
MI_CLEARWINDOW(mi);
/* Do not want any exposure events from XCopyPlane */
XSetGraphicsExposures(display, MI_GC(mi), False);
}
/***************************************************************/
void
release_strange(ModeInfo * mi)
{
if (Root != NULL) {
int screen;
for (screen = 0; screen < MI_NUM_SCREENS(mi); ++screen)
free_strange(MI_DISPLAY(mi), &Root[screen]);
free(Root);
Root = (ATTRACTOR *) NULL;
}
}
#endif /* MODE_strange */
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