//************************************************************************** // Interactive Barnsley Fern Applet by Rafael Wiemker, April 1996 // // (wasting his time on these stupid games // instead of doing the real work assigned to him, // such as finishing his thesis etc.... ) // // ( computed with a Random Iterated Functions System [IFS] // with four affine mappings) // // based on H.-O. Peitgen, H. J"urgens, D. Saupe: // Bausteine des Chaos: Fraktale // Springer, New York, Heidelberg 1992. // // The method which actually did cost me some sweat is // ColFernPanel.update FacPhi(), ie, determining such parameters that fit // together nicely. The parameter tuning seems to be a pretty // delicate affair. Probably one could do better. // //************************************************************************** import java.awt.*; import java.applet.*; public class ColFern extends Applet implements Runnable { Graphics g; Thread runner; ColFernPanel controls; double xcurr, ycurr; double[] xarr = new double[100]; double[] yarr = new double[100]; Color[] carr = new Color[100]; double[][][] M = new double[4][2][3]; int wid = 480; int hei = 580; float[][] img = new float[wid][hei]; double ly = (double)hei; // plot offset double lx = 0; // plot offset public void start() { if (runner == null); { runner = new Thread(this); runner.start(); } } public void stop() { if (runner != null); { runner.stop(); runner = null; } } public void init() { //resize(680,473); g = getGraphics(); // current graphics environment setBackground(Color.white); setLayout(new FlowLayout()); controls = new ColFernPanel(this); add("NORTH",controls); M = controls.M; xcurr = controls.x0; ycurr = controls.y0; ly = controls.defaulth; } public void run() { while ( true ) { repaint(); nextpoint(); try {Thread.sleep(20);} catch (InterruptedException e) { } } } public void update(Graphics g) { paint(g); // i.e. don't clear screen } public void paint(Graphics g) { for (int i=0; i<100; i++) { g.setColor(carr[i]); g.fillRect( (int)(xarr[i]-lx),(int)(ly-yarr[i]),1,1); } } public void clearAndUpdate() { g.clearRect(0,0,size().width,size().height); M = controls.M; xcurr = controls.x0; ycurr = controls.y0; lx = xcurr - controls.defaultw / 2; } private void nextpoint( ) { double z; for (int i=0; i<100; i++) { z = Math.random(); if (z < 0.05) { // altered from originally 0.02 mapping(0); } else if (z < 0.17) { mapping(1); } else if (z < 0.30) { mapping(2); } else if (z < 1.00) { mapping(3); } xarr[i] = xcurr; yarr[i] = ycurr; carr[i] = controls.drawColor; int xaddr = (int)(xarr[i]-lx); int yaddr = (int)(ly-yarr[i]); if ((xaddr >= 0) && (xaddr < wid) && (yaddr >= 0) && (yaddr < hei)) { if (img[xaddr][yaddr] == 0.0f) { img[xaddr][yaddr] = 1.0f; } else img[xaddr][yaddr] *= 0.9f; carr[i] = Color.getHSBColor( controls.drawColorHue,1.0f,img[xaddr][yaddr]); //carr[i] = Color.getHSBColor(img[xaddr][yaddr],1.0f,1.0f); } } // for i } private void mapping(int id) { double xnew, ynew; xnew = M[id][0][0]*xcurr + M[id][0][1]*ycurr + M[id][0][2]; ynew = M[id][1][0]*xcurr + M[id][1][1]*ycurr + M[id][1][2]; xcurr = xnew; ycurr = ynew; } } //--------------------------------------------------------------------------- class ColFernPanel extends Panel { ColFern outerParent; Label l1, l2, l3, l4, l5; Scrollbar sb1, sb2, sb3, sb4, sb5; int v1, v2, v3, v4, v5; Color drawColor = Color.getHSBColor(0.44f,1.0f,1.0f); float drawColorHue = 0.44f; double x0, y0; // start values double xstart = 0.5; // seed point, fix point of mapping [0] double ystart = 0.0; double[][][] M = new double[4][2][3]; // affine mappings[0..3] double[] xfac = new double[4]; // branch factors double[] yfac = new double[4]; double[] xphi = new double[4]; // branch angles double[] yphi = new double[4]; double[] xfix = new double[4]; // branch off points double[] yfix = new double[4]; double branchAngle , shootAngle , branchSize ; double defaulth = 580; // default overall height double defaultw = 480; // default overall size double w; // actual overall size ColFernPanel(ColFern fern) { outerParent = fern; setBackground(Color.gray); setLayout(new GridLayout(3,4)); // 4 hor. lines + 3 vert. lines l1 = new Label("0", Label.CENTER); sb1 = new Scrollbar(Scrollbar.HORIZONTAL,0,1,-45,45); l2 = new Label("0", Label.CENTER); sb2 = new Scrollbar(Scrollbar.HORIZONTAL,0,1,0,170); l3 = new Label("0", Label.CENTER); sb3 = new Scrollbar(Scrollbar.HORIZONTAL,0,1,0,100); l4 = new Label("100", Label.CENTER); sb4 = new Scrollbar(Scrollbar.HORIZONTAL,0,1,0,35); l5 = new Label("0", Label.CENTER); sb5 = new Scrollbar(Scrollbar.HORIZONTAL,0,1,0,200); Panel p1 = new Panel(); Panel p2 = new Panel(); Panel p3 = new Panel(); p1.add(new Button("original Barnsley")); p1.add(new Label("color:", Label.RIGHT)); p1.add(l4); p1.add(sb4); p3.add(new Label("curvature:", Label.RIGHT)); p3.add(l1); p3.add(sb1); p3.add(new Label("branch angle:", Label.RIGHT)); p3.add(l2); p3.add(sb2); p2.add(new Label("overall size:", Label.RIGHT)); p2.add(l5); p2.add(sb5); p2.add(new Label("branch size:", Label.RIGHT)); p2.add(l3); p2.add(sb3); add(p1); add(p2); add(p3); // initialize: sb4.setValue(16); // color sb5.setValue(100); // overall size w = defaultw; resetMappings(); updateScrollbars(); } public boolean handleEvent(Event evt) { if (evt.target instanceof Scrollbar) { updateScrollbars(); updateFacPhi(); updateM(); outerParent.clearAndUpdate(); return true; } else if (evt.target instanceof Button) { resetMappings(); updateScrollbars(); outerParent.clearAndUpdate(); return true; } else return false; } void resetMappings() { sb1.setValue(3); sb2.setValue(50); sb3.setValue(30); // almost original Barnsley Parameters // slightly changed by Peitgen/J"urgens/Saupe int id = 0; // stem M[id][0][0] = 0.0; // x : x multiplier M[id][0][1] = 0.0; // x : y multiplier M[id][0][2] = 0.5*w; // x : offset M[id][1][0] = 0.0; // y : x multiplier M[id][1][1] = 0.27; // y : y multiplier M[id][1][2] = 0.0*w; // y : offset id = 1; // right leaf M[id][0][0] = -0.139; // x : x multiplier M[id][0][1] = 0.263; // x : y multiplier M[id][0][2] = 0.57*w; // x : offset M[id][1][0] = 0.246; // y : x multiplier M[id][1][1] = 0.224; // y : y multiplier M[id][1][2] = -0.036*w; // y : offset id = 2; // left leaf M[id][0][0] = 0.17; // x : x multiplier M[id][0][1] = -0.215; // x : y multiplier M[id][0][2] = 0.408*w; // x : offset M[id][1][0] = 0.222; // y : x multiplier M[id][1][1] = 0.176; // y : y multiplier M[id][1][2] = 0.0893*w; // y : offset id = 3; // shoot M[id][0][0] = 0.781; // x : x multiplier M[id][0][1] = 0.034; // x : y multiplier M[id][0][2] = 0.1075*w; // x : offset M[id][1][0] = -0.032; // y : x multiplier M[id][1][1] = 0.739; // y : y multiplier M[id][1][2] = 0.27*w; // y : offset } void updateScrollbars() { v1 = sb1.getValue(); v2 = sb2.getValue(); v3 = sb3.getValue(); v4 = sb4.getValue(); v5 = sb5.getValue(); shootAngle = - v1 / 180.0 * 3.1415; branchAngle = v2 / 180.0 * 3.1415; branchSize = v3 / 100.0; w = v5/100.0f * defaultw; x0 = xstart*w; y0 = ystart*w; l1.setText(String.valueOf(v1)+" deg"); l2.setText(String.valueOf(v2)+" deg"); l3.setText(String.valueOf(branchSize)); l4.setText(String.valueOf(v4*10)+" deg hue"); l5.setText(String.valueOf(v5)+"%"); drawColor = Color.getHSBColor((float)v4/36,1.0f,1.0f); drawColorHue = (float)v4/36; } void updateFacPhi() { double xstemloc = 0.5; double shootfac = 0.78; double stemheight = 0.21; double stemthick = 0.01; double overallheight = 0.0; // determine will-be-overallheight: if (shootAngle != 0) { for (int i=0; i < (Math.abs(3.1415/2/shootAngle)+2); i++) { overallheight += stemheight * Math.pow(shootfac,i) * Math.cos(i*shootAngle); } } else overallheight = 0.80; xfix[0] = xfix[1] = xfix[2] = xfix[3] = xstemloc*w; yfix[0] = 0.00*stemheight*w; yfix[1] = 0.25*stemheight*w; yfix[2] = 0.75*stemheight*w; yfix[3] = 1.00*stemheight*w; xfac[0] = stemthick ; yfac[0] = stemheight / overallheight; xfac[1] = -branchSize ; xfac[2] = yfac[1] = yfac[2] = branchSize ; xfac[3] = yfac[3] = shootfac; xphi[0] = yphi[0] = 0.0; xphi[1] = yphi[1] = -branchAngle ; xphi[2] = yphi[2] = branchAngle ; xphi[3] = yphi[3] = shootAngle ; } void updateM() { for (int i=0; i < 4; i++) { // factors: M[i][0][0] = xfac[i]*Math.cos(xphi[i]); // x : x multiplier M[i][0][1] = -yfac[i]*Math.sin(yphi[i]) ; // x : y multiplier M[i][1][0] = xfac[i]*Math.sin(xphi[i]); // y : x multiplier M[i][1][1] = yfac[i]*Math.cos(xphi[i]); // y : y multiplier // offsets: M[i][0][2] = xfix[i] - ( M[i][0][0]*x0 + M[i][0][1]*y0 ); M[i][1][2] = yfix[i] - ( M[i][1][0]*x0 + M[i][1][1]*y0 ); } } } //---------------------------------------------------------------------------