+++ /dev/null
-/* -*- Mode: C; tab-width: 4 -*- */
-/* flow --- flow of strange bees */
-
-#if !defined( lint ) && !defined( SABER )
-static const char sccsid[] = "@(#)flow.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.
- *
- * "flow" shows a variety of continuous phase-space flows around strange
- * attractors. It includes the well-known Lorentz mask (the "Butterfly"
- * of chaos fame), two forms of Rossler's "Folded Band" and Poincare'
- * sections of the "Birkhoff Bagel" and Duffing's forced occilator.
- *
- * Revision History:
- * 31-Nov-98: [TDA] Added Duffing (what a strange day that was :) DAB)
- * Duffing's forced oscillator has been added to the formula list and
- * the parameters section has been updated to display it in Poincare'
- * section.
- * 30-Nov-98: [TDA] Added travelling perspective option
- * A more exciting point-of-view has been added to all autonomous flows.
- * This views the flow as seen by a particle moving with the flow. In the
- * metaphor of the original code, I've attached a camera to one of the
- * trained bees!
- * 30-Nov-98: [TDA] Much code cleanup.
- * 09-Apr-97: [TDA] Ported to xlockmore-4
- * 18-Jul-96: Adapted from swarm.c Copyright (c) 1991 by Patrick J. Naughton.
- * 31-Aug-90: Adapted from xswarm by Jeff Butterworth. (butterwo@ncsc.org)
- */
-
-#ifdef STANDALONE
-# define PROGCLASS "Flow"
-# define HACK_INIT init_flow
-# define HACK_DRAW draw_flow
-# define flow_opts xlockmore_opts
-# define DEFAULTS "*delay: 1000 \n" \
- "*count: 1024 \n" \
- "*cycles: 3000 \n" \
- "*ncolors: 200 \n"
-# define SMOOTH_COLORS
-# include "xlockmore.h" /* in xscreensaver distribution */
-# include "erase.h"
-
-#else /* STANDALONE */
-# include "xlock.h" /* in xlockmore distribution */
-#endif /* STANDALONE */
-
-ModeSpecOpt flow_opts = { 0, NULL, 0, NULL, NULL };
-
-#ifdef USE_MODULES
-ModStruct flow_description = {
- "flow", "init_flow", "draw_flow", "release_flow",
- "refresh_flow", "init_flow", NULL, &flow_opts,
- 1000, 1024, 3000, 1, 64, 1.0, "",
- "Shows dynamic strange attractors", 0, NULL
-};
-
-#endif
-
-typedef struct {
- double x;
- double y;
- double z;
-} dvector;
-
-typedef struct {
- double a, b, c;
-} Par;
-
-/* Macros */
-#define X(t,b) (sp->p[t][b].x)
-#define Y(t,b) (sp->p[t][b].y)
-#define Z(t,b) (sp->p[t][b].z)
-#define balance_rand(v) ((LRAND()/MAXRAND*(v))-((v)/2)) /* random around 0 */
-#define SCALE_X(A) (sp->width/2+sp->width/sp->size*(A))
-#define SCALE_Y(A) (sp->height/2+sp->height/sp->size*(A))
-
-typedef struct {
- int width;
- int height;
- int count;
- double size;
-
- int beecount; /* number of bees */
- XSegment *csegs; /* bee lines */
- int *cnsegs;
- XSegment *old_segs; /* old bee lines */
- int nold_segs;
- double step;
- dvector centre; /* centre */
- struct {
- double depth;
- double height;
- } view;
- dvector *p[2]; /* bee positions x[time][bee#] */
- struct {
- double theta;
- double dtheta;
- double phi;
- double dphi;
- } tumble;
- dvector (*ODE) (Par par, double x, double y, double z);
- Par par;
-} flowstruct;
-
-static flowstruct *flows = NULL;
-
-static dvector
-Lorentz(Par par, double x, double y, double z)
-{
- dvector d;
-
- d.x = par.a * (y - x);
- d.y = x * (par.b - z) - y;
- d.z = x * y - par.c * z;
- return d;
-}
-
-static dvector
-Rossler(Par par, double x, double y, double z)
-{
- dvector d;
-
- d.x = -(y + par.a * z);
- d.y = x + y * par.b;
- d.z = par.c + z * (x - 5.7);
- return d;
-}
-
-static dvector
-RosslerCone(Par par, double x, double y, double z)
-{
- dvector d;
-
- d.x = -(y + par.a * z);
- d.y = x + y * par.b - z * z * par.c;
- d.z = 0.2 + z * (x - 5.7);
- return d;
-}
-
-static dvector
-Birkhoff(Par par, double x, double y, double z)
-{
- dvector d;
-
- d.x = -y + par.b * sin(z);
- d.y = 0.7 * x + par.a * y * (0.1 - x * x);
- d.z = par.c;
- return d;
-}
-
-static dvector
-Duffing(Par par, double x, double y, double z)
-{
- dvector d;
-
- d.x = -par.a * x - y/2 - y * y * y/8 + par.b * cos(z);
- d.y = 2*x;
- d.z = par.c;
- return d;
-}
-
-void
-init_flow(ModeInfo * mi)
-{
- flowstruct *sp;
- int b;
- double beemult = 1;
- dvector range;
- static int allocated = 0;
-
- if (flows == NULL) {
- if ((flows = (flowstruct *) calloc(MI_NUM_SCREENS(mi),
- sizeof (flowstruct))) == NULL)
- return;
- }
- sp = &flows[MI_SCREEN(mi)];
-
- sp->count = 0;
-
- sp->width = MI_WIDTH(mi);
- sp->height = MI_HEIGHT(mi);
-
- sp->tumble.theta = balance_rand(M_PI);
- sp->tumble.phi = balance_rand(M_PI);
- sp->tumble.dtheta = 0.002;
- sp->tumble.dphi = 0.001;
- sp->view.height = 0;
- sp->view.depth = 0; /* no perspective view */
-
- switch (NRAND(8)) {
- case 0:
- sp->view.depth = 10;
- sp->view.height = 0.2;
- beemult = 3;
- case 1:
- sp->ODE = Lorentz;
- sp->step = 0.02;
- sp->size = 60;
- sp->centre.x = 0;
- sp->centre.y = 0;
- sp->centre.z = 24;
- range.x = 5;
- range.y = 5;
- range.z = 1;
- sp->par.a = 10 + balance_rand(5);
- sp->par.b = 28 + balance_rand(5);
- sp->par.c = 2 + balance_rand(1);
- break;
- case 2:
- sp->view.depth = 10;
- sp->view.height = 0.1;
- beemult = 4;
- case 3:
- sp->ODE = Rossler;
- sp->step = 0.05;
- sp->size = 24;
- sp->centre.x = 0;
- sp->centre.y = 0;
- sp->centre.z = 3;
- range.x = 4;
- range.y = 4;
- range.z = 7;
- sp->par.a = 2 + balance_rand(1);
- sp->par.b = 0.2 + balance_rand(0.1);
- sp->par.c = 0.2 + balance_rand(0.1);
- break;
- case 4:
- sp->view.depth = 10;
- sp->view.height = 0.1;
- beemult = 3;
- case 5:
- sp->ODE = RosslerCone;
- sp->step = 0.05;
- sp->size = 24;
- sp->centre.x = 0;
- sp->centre.y = 0;
- sp->centre.z = 3;
- range.x = 4;
- range.y = 4;
- range.z = 4;
- sp->par.a = 2;
- sp->par.b = 0.2;
- sp->par.c = 0.25 + balance_rand(0.09);
- break;
- case 6:
- sp->ODE = Birkhoff;
- sp->step = 0.04;
- sp->size = 2.6;
- sp->centre.x = 0;
- sp->centre.y = 0;
- sp->centre.z = 0;
- range.x = 3;
- range.y = 4;
- range.z = 0;
- sp->par.a = 10 + balance_rand(5);
- sp->par.b = 0.35 + balance_rand(0.25);
- sp->par.c = 1.57;
- sp->tumble.theta = 0;
- sp->tumble.phi = 0;
- sp->tumble.dtheta = 0;
- sp->tumble.dphi = 0;
- break;
- case 7:
- default:
- sp->ODE = Duffing;
- sp->step = 0.02;
- sp->size = 30;
- sp->centre.x = 0;
- sp->centre.y = 0;
- sp->centre.z = 0;
- range.x = 20;
- range.y = 20;
- range.z = 0;
- sp->par.a = 0.2 + balance_rand(0.1);
- sp->par.b = 27.0 + balance_rand(3.0);
- sp->par.c = 1.33;
- sp->tumble.theta = 0;
- sp->tumble.phi = 0;
- sp->tumble.dtheta = -NRAND(2)*sp->par.c*sp->step;
- sp->tumble.dphi = 0;
- beemult = 0.5;
- break;
- }
-
- sp->beecount = beemult * MI_COUNT(mi);
- if (sp->beecount < 0) /* random variations */
- sp->beecount = NRAND(-sp->beecount) + 1; /* Minimum 1 */
-
- /* Clear the background. */
- MI_CLEARWINDOW(mi);
-
- if(!allocated || sp->beecount != allocated){ /* reallocate */
- if (sp->csegs != NULL) {
- (void) free((void *) sp->csegs);
- sp->csegs = NULL;
- }
- if (sp->cnsegs != NULL) {
- (void) free((void *) sp->cnsegs);
- sp->cnsegs = NULL;
- }
- if (sp->old_segs != NULL) {
- (void) free((void *) sp->old_segs);
- sp->old_segs = NULL;
- }
- if (sp->p[0] != NULL) {
- (void) free((void *) sp->p[0]);
- sp->p[0] = NULL;
- }
- if (sp->p[1] != NULL) {
- (void) free((void *) sp->p[1]);
- sp->p[1] = NULL;
- }
- }
-
- /* Allocate memory. */
-
- if (!sp->csegs) {
- sp->csegs = (XSegment *) malloc(sizeof (XSegment) * sp->beecount
- * MI_NPIXELS(mi));
- sp->cnsegs = (int *) malloc(sizeof (int) * MI_NPIXELS(mi));
-
- sp->old_segs = (XSegment *) malloc(sizeof (XSegment) * sp->beecount);
- sp->p[0] = (dvector *) malloc(sizeof (dvector) * sp->beecount);
- sp->p[1] = (dvector *) malloc(sizeof (dvector) * sp->beecount);
- }
-
- /* Initialize point positions, velocities, etc. */
-
- for (b = 0; b < sp->beecount; b++) {
- X(1, b) = X(0, b) = balance_rand(range.x);
- Y(1, b) = Y(0, b) = balance_rand(range.y);
- Z(1, b) = Z(0, b) = balance_rand(range.z);
- }
-}
-
-void
-draw_flow(ModeInfo * mi)
-{
- Display *display = MI_DISPLAY(mi);
- Window window = MI_WINDOW(mi);
- GC gc = MI_GC(mi);
- flowstruct *sp = &flows[MI_SCREEN(mi)];
- int b, c, i;
- int col, ix;
- double M[3][3]; /* transformation matrix */
-
- if(!sp->view.depth){ /* simple 3D tumble */
- double sint, cost, sinp, cosp;
- sp->tumble.theta += sp->tumble.dtheta;
- sp->tumble.phi += sp->tumble.dphi;
- sint = sin(sp->tumble.theta);
- cost = cos(sp->tumble.theta);
- sinp = sin(sp->tumble.phi);
- cosp = cos(sp->tumble.phi);
- M[0][0]= cost; M[0][1]=-sint*cosp; M[0][2]= sint*sinp;
- M[1][0]= sint; M[1][1]= cost*cosp; M[1][2]=-cost*sinp;
- M[2][0]= 0; M[2][1]= 0; M[2][2]= 1;
- } else { /* initialize matrix */
- M[0][0]= 0; M[0][1]= 0; M[0][2]= 0;
- M[1][0]= 0; M[1][1]= 0; M[1][2]= 0;
- M[2][0]= 0; M[2][1]= 0; M[2][2]= 0;
-
- }
-
- for (col = 0; col < MI_NPIXELS(mi); col++)
- sp->cnsegs[col] = 0;
-
- MI_IS_DRAWN(mi) = True;
-
- /* <=- Bees -=> */
- for (b = 0; b < sp->beecount; b++) {
- /* Age the arrays. */
- X(1, b) = X(0, b);
- Y(1, b) = Y(0, b);
- Z(1, b) = Z(0, b);
-
- /* 2nd order Kunge Kutta */
- {
- dvector k1, k2;
-
- k1 = sp->ODE(sp->par, X(1, b), Y(1, b), Z(1, b));
- k1.x *= sp->step;
- k1.y *= sp->step;
- k1.z *= sp->step;
- k2 = sp->ODE(sp->par, X(1, b) + k1.x, Y(1, b) + k1.y, Z(1, b) + k1.z);
- k2.x *= sp->step;
- k2.y *= sp->step;
- k2.z *= sp->step;
- X(0, b) = X(1, b) + (k1.x + k2.x) / 2.0;
- Y(0, b) = Y(1, b) + (k1.y + k2.y) / 2.0;
- Z(0, b) = Z(1, b) + (k1.z + k2.z) / 2.0;
- }
-
- /* Colour according to bee */
- col = b % (MI_NPIXELS(mi) - 1);
- ix = col * sp->beecount + sp->cnsegs[col];
-
- /* Fill the segment lists. */
-
- if(sp->view.depth) /* perspective view has special points */
- if(b==0){ /* point of view */
- sp->centre.x=X(0, b);
- sp->centre.y=Y(0, b);
- sp->centre.z=Z(0, b);
- }else if(b==1){ /* neighbour: used to compute local axes */
- double x[3], p[3], x2=0, xp=0;
- int j;
-
- /* forward */
- x[0] = X(0, 0) - X(1, 0);
- x[1] = Y(0, 0) - Y(1, 0);
- x[2] = Z(0, 0) - Z(1, 0);
-
- /* neighbour */
- p[0] = X(0, 1) - X(1, 0);
- p[1] = Y(0, 1) - Y(1, 0);
- p[2] = Z(0, 1) - Z(1, 0);
-
- for(i=0; i<3; i++){
- x2+= x[i]*x[i]; /* X . X */
- xp+= x[i]*p[i]; /* X . P */
- M[0][i] = x[i]; /* X */
- }
-
- for(i=0; i<3; i++) /* (X x P) x X */
- M[1][i] = x2*p[i] - xp*x[i]; /* == (X . X) P - (X . P) X */
-
- M[2][0] = x[1]*p[2] - x[2]*p[1]; /* X x P */
- M[2][1] = -x[0]*p[2] + x[2]*p[0];
- M[2][2] = x[0]*p[1] - x[1]*p[0];
-
- /* normalise axes */
- for(j=0; j<3; j++){
- double A=0;
- for(i=0; i<3; i++) A+=M[j][i]*M[j][i]; /* sum squares */
- A=sqrt(A);
- for(i=0; i<3; i++) M[j][i]/=A;
- }
-
- X(0, 1)=X(0, 0)+M[1][0]; /* adjust neighbour */
- Y(0, 1)=Y(0, 0)+M[1][1];
- Z(0, 1)=Z(0, 0)+M[1][2];
-
-#if 0 /* display local axes for testing */
- X(1, b)=X(0, 0);
- Y(1, b)=Y(0, 0);
- Z(1, b)=Z(0, 0);
- }else if(b==2){
- X(0, b)=X(0, 0)+0.5*M[0][0];
- Y(0, b)=Y(0, 0)+0.5*M[0][1];
- Z(0, b)=Z(0, 0)+0.5*M[0][2];
- X(1, b)=X(0, 0);
- Y(1, b)=Y(0, 0);
- Z(1, b)=Z(0, 0);
- }else if(b==3){
- X(0, b)=X(0, 0)+1.5*M[2][0];
- Y(0, b)=Y(0, 0)+1.5*M[2][1];
- Z(0, b)=Z(0, 0)+1.5*M[2][2];
- X(1, b)=X(0, 0);
- Y(1, b)=Y(0, 0);
- Z(1, b)=Z(0, 0);
-#endif
- }
-
- for(i=0; i<2; i++){
- double x=X(i,b)-sp->centre.x;
- double y=Y(i,b)-sp->centre.y;
- double z=Z(i,b)-sp->centre.z;
- double X=M[0][0]*x + M[0][1]*y + M[0][2]*z;
- double Y=M[1][0]*x + M[1][1]*y + M[1][2]*z;
- double Z=M[2][0]*x + M[2][1]*y + M[2][2]*z+sp->view.height;
- double absx, absy;
- if(sp->view.depth){
- if(X <= 0) break;
- absx=SCALE_X(sp->view.depth*Y/X);
- absy=SCALE_Y(sp->view.depth*Z/X);
- if(absx < -sp->width || absx > 2*sp->width ||
- absy < -sp->height || absy > 2*sp->height)
- break;
- }else{
- absx=SCALE_X(X);
- absy=SCALE_Y(Y);
- }
- if(i){
- sp->csegs[ix].x1 = (short) absx;
- sp->csegs[ix].y1 = (short) absy;
- }else{
- sp->csegs[ix].x2 = (short) absx;
- sp->csegs[ix].y2 = (short) absy;
- }
- }
- if(i == 2) /* both assigned */
- sp->cnsegs[col]++;
- }
- if (sp->count) { /* erase */
- XSetForeground(display, gc, MI_BLACK_PIXEL(mi));
- XDrawSegments(display, window, gc, sp->old_segs, sp->nold_segs);
- }
-
- if (MI_NPIXELS(mi) > 2){ /* render colour */
- for (col = 0; col < MI_NPIXELS(mi); col++)
- if (sp->cnsegs[col] > 0) {
- XSetForeground(display, gc, MI_PIXEL(mi, col));
- XDrawSegments(display, window, gc,
- sp->csegs + col * sp->beecount, sp->cnsegs[col]);
- }
- } else { /* render mono */
- XSetForeground(display, gc, MI_WHITE_PIXEL(mi));
- XDrawSegments(display, window, gc,
- sp->csegs + col * sp->beecount, sp->cnsegs[col]);
- }
-
- /* Copy to erase-list */
- for (col = 0, c = 0; col < MI_NPIXELS(mi); col++)
- for (b = 0; b < sp->cnsegs[col]; b++)
- sp->old_segs[c++] = (sp->csegs + col * sp->beecount)[b];
- sp->nold_segs = c;
-
- if (++sp->count > MI_CYCLES(mi)) /* pick a new flow */
- init_flow(mi);
-}
-
-void
-release_flow(ModeInfo * mi)
-{
- if (flows != NULL) {
- int screen;
-
- for (screen = 0; screen < MI_NUM_SCREENS(mi); screen++) {
- flowstruct *sp = &flows[screen];
-
- if (sp->csegs != NULL)
- (void) free((void *) sp->csegs);
- if (sp->cnsegs != NULL)
- (void) free((void *) sp->cnsegs);
- if (sp->old_segs != NULL)
- (void) free((void *) sp->old_segs);
- if (sp->p[0] != NULL)
- (void) free((void *) sp->p[0]);
- if (sp->p[1] != NULL)
- (void) free((void *) sp->p[1]);
- }
- (void) free((void *) flows);
- flows = NULL;
- }
-}
-
-void
-refresh_flow(ModeInfo * mi)
-{
- MI_CLEARWINDOW(mi);
-}
projects / xscreensaver / blobdiff