by Ira Greenberg. Using 2-dimensional arrays, record end points and replot scribbles between points.
Original Processing.org Example: ScribblePlotter
// All Examples Written by Casey Reas and Ben Fry // unless otherwise stated. // some scribble style constants that control // how the scribble plotting works int SCRIBBLE = 0; int HATCHING = 1; void setup(){ size(200, 200); background(0); // create arrays to hold x, y coords float[]x = new float[4]; float[]y = new float[4]; // create a convenient 2-dimensional // array to hold x, y arrays float[][]xy = {x, y}; // record points // x positions xy[0][0] = 25; xy[0][1] = 175; xy[0][2] = 175; xy[0][3] = 25; // y positions xy[1][0] = 25; xy[1][1] = 25; xy[1][2] = 175; xy[1][3] = 175; // call plotting function makeRect(xy); } void makeRect(float[][]pts){ stroke(255); smooth(); // scribble variables, that get passed as arguments to the scribble function int steps = 100; float scribVal = 3.0; for (int i=0; i< pts[0].length; i++){ //plots vertices strokeWeight(5); point(pts[0][i], pts[1][i]); // call scribble function strokeWeight(.5); if (i>0){ scribble(pts[0][i], pts[1][i], pts[0][i-1], pts[1][i-1], steps, scribVal, SCRIBBLE); } if (i== pts[0].length-1){ // show some hatching between last 2 points scribble(pts[0][i], pts[1][i], pts[0][0], pts[1][0], steps, scribVal*2, HATCHING); } } } /* scribble function plots lines between end points, determined by steps and scribVal arguments. 2 styles are available: SCRIBBLE and HATCHING, which are interestingly only dependent on parentheses placement in the line() function calls. */ void scribble(float x1, float y1, float x2, float y2, int steps, float scribVal, int style){ float xStep = (x2-x1)/steps; float yStep = (y2-y1)/steps; for (int i = 0; i<steps; i++){ if(style == SCRIBBLE){ if (i<steps-1){ line(x1, y1, x1+=xStep+random(-scribVal, scribVal), y1+=yStep+random(-scribVal, scribVal)); } else { // extra line needed to attach line back to point- not necessary in HATCHING style line(x1, y1, x2, y2); } } else if (style == HATCHING){ line(x1, y1, (x1+=xStep)+random(-scribVal, scribVal), (y1+=yStep)+random(-scribVal, scribVal)); } } }