fixed and sorted/added comments to L-System
This commit is contained in:
Jürg Hallenbarter
@@ -1,178 +1,257 @@
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let angle = 3.141592653589*1.5;
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let angleDecrement = 1;
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let stepSize = 10;
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let widthIncrement = 1;
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let currentWidth = 1;
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let currentPosition = [501 / 2, 500];
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let fractalst = "FF+[+F-F-F]-[-F+F+F]";
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let stackList = [];
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let lineLenghtScaleFactor = 1.5;
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/*
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L-System Fractal Generator
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The following characters have a geometric interpretation:
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Character Meaning
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F Move forward by line length drawing a line
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f Move forward by line length without drawing a line
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+ Turn left by turning angle
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- Turn right by turning angle
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| Reverse direction (ie: turn by 180 degrees)
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[ Push current drawing state onto stack
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] Pop current drawing state from the stack
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# Increment the line width by line width increment
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! Decrement the line width by line width increment
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@ Draw a dot with line width radius
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{ Open a polygon
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} Close a polygon and fill it with fill colour
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> Multiply the line length by the line length scale factor
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< Divide the line length by the line length scale factor
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& Swap the meaning of + and -
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( Decrement turning angle by turning angle increment
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) Increment turning angle by turning angle increment
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*/
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let angle = Math.PI * 1.5;
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let turningAngle = Math.PI * 0.5;
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let lineLength = 5;
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let lineWidthIncrement = 1;
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let currentLineWidth = 1;
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let currentPosition = [0, 0];
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let stateStack = [];
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let lineLengthScaleFactor = 1.5;
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let swapPlusMinusState = false;
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let turningAngleIncrement = 0.1;
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let polygonVertices = [];
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let polygonOpen = false;
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//FF+[+F-F-F]-[-F+F+F] fork
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let axiom = 'F+F+F+F';
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let maxIterations = 4;
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const maxCalculations = 50000;
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let rules = {
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'F': 'FF+F-F+F+FF'
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};
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// Generate the fractal string from axiom and rules
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for (let i = 0; i < maxIterations; i++) {
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if (axiom.length > maxCalculations) {//hard coded limit to prevent infinite loops
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console.log('Reached max calculations, stopping at iteration', i);
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break;
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}
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let newAxiom = '';
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for (let char of axiom) {//loop through each character in the axiom and replace it with the corresponding rule
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if (rules[char]) {
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newAxiom += rules[char];
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} else {
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newAxiom += char;
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}
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}
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axiom = newAxiom;
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}
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function setup() {
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console.log("setup");
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createCanvas(windowWidth, windowHeight);
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background(255, 255, 255)
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background(255, 255, 255);
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noFill();
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stroke(0, 0, 0);
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strokeWeight(1);
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currentPosition = [width / 2, height];
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strokeWeight(currentLineWidth);
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currentPosition = [width / 2, height - 100];
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generateFractal();
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}
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function generateFractal() {
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for (let i = 0; i < fractalst.length; i++) {
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let c = fractalst.charAt(i);
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for (let i = 0; i < axiom.length; i++) {
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let c = axiom.charAt(i);
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switch (c) {
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case "F":
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forward();
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break;
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case "+":
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plus();
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break;
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case "-":
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minus();
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moveForwardDraw();
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break;
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case "f":
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forwardNoLine();
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moveForwardNoDraw();
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break;
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case "+":
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turnLeft();
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break;
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case "-":
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turnRight();
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break;
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case "|":
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reverseDirection();
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break;
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case "#":
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lineWidthIncrement();
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break;
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case "!":
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lineWidthDecrement();
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break;
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case "[":
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pushStack(i);
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pushState(i);
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break;
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case "]":
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popStack(i);
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popState(i);
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break;
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case ">":
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lineWidthMultiply();
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case "#":
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incrementLineWidth();
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break;
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case "<":
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lineWidthDivide();
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break;
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case "&":
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swapPlusMinus();
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case "!":
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decrementLineWidth();
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break;
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case "@":
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drawDot();
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break;
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case "{":
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openPolygon();
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break;
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case "}":
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closePolygon();
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break;
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case ">":
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multiplyLineLength();
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break;
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case "<":
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divideLineLength();
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break;
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case "&":
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swapPlusMinus();
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break;
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case ")":
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angleIncrement();
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incrementTurningAngle();
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break;
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case "(":
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angleDecrement();
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decrementTurningAngle();
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break;
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default:
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console.log("unrecognized character",c);
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// Ignore characters not in the specification (like X)
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break;
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}
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}
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}
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function minus() {
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if (swapPlusMinusState) {
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angle += angleDecrement;
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return
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// F: Move forward by line length drawing a line
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function moveForwardDraw() {
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let x = currentPosition[0] + cos(angle) * lineLength;
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let y = currentPosition[1] + sin(angle) * lineLength;
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if (polygonOpen) {
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polygonVertices.push([x, y]);
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} else {
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line(currentPosition[0], currentPosition[1], x, y);
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}
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angle -= angleDecrement;
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}
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function plus() {
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if (swapPlusMinusState) {
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angle -= angleDecrement;
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return
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}
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angle += angleDecrement;
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}
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function lineWidthIncrement(){
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currentWidth + widthIncrement;
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strokeWeight(currentWidth);
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}
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function lineWidthDecrement(){
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currentWidth - widthIncrement;
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strokeWeight(currentWidth);
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}
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function forward() {
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let x = currentPosition[0] + cos(angle) * stepSize;
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let y = currentPosition[1] + sin(angle) * stepSize;
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line(currentPosition[0], currentPosition[1], x, y);
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currentPosition = [x, y];
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}
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function forwardNoLine(){
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let x = currentPosition[0] + cos(angle) * stepSize;
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let y = currentPosition[1] + sin(angle) * stepSize;
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// f: Move forward by line length without drawing a line
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function moveForwardNoDraw() {
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let x = currentPosition[0] + cos(angle) * lineLength;
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let y = currentPosition[1] + sin(angle) * lineLength;
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currentPosition = [x, y];
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}
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function backward() {
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let x = currentPosition[0] - cos(angle) * stepSize;
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let y = currentPosition[1] - sin(angle) * stepSize;
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line(currentPosition[0], currentPosition[1], x, y);
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currentPosition = [x, y];
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}
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function reverseDirection(){
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angle - 3.14159265358979323;
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}
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function pushStack(i){
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console.log(angle)
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stackList.push([i,currentPosition[0],currentPosition[1],angle,currentWidth]);
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}
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function popStack(i){
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stackToPop = stackList.length - 1;
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console.log(stackList[stackToPop])
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currentPosition = [stackList[stackToPop][1],stackList[stackToPop][2]];
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angle = stackList[stackToPop][3];
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strokeWeight[stackList[stackToPop][4]]
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}
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function lineWidthMultiply(){
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currentWidth * lineLenghtScaleFactor;
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strokeWeight(currentWidth);
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}
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function lineWidthDivide(){
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currentWidth / lineLenghtScaleFactor;
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strokeWeight(currentWidth);
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}
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function swapPlusMinus(){
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// +: Turn left by turning angle
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function turnLeft() {
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if (swapPlusMinusState) {
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swapPlusMinusState = false;
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angle -= turningAngle;
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return
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}
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swapPlusMinusState = true;
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angle += turningAngle;
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}
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// -: Turn right by turning angle
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function turnRight() {
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if (swapPlusMinusState) {
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angle += turningAngle;
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return
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}
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angle -= turningAngle;
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}
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// |: Reverse direction (turn by 180 degrees)
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function reverseDirection() {
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angle += Math.PI;
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}
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// [: Push current drawing state onto stack
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function pushState(i) {
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stateStack.push([i, currentPosition[0], currentPosition[1], angle, currentLineWidth]);
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}
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// ]: Pop current drawing state from the stack
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function popState(i) {
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let stackIndex = stateStack.length - 1;
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currentPosition = [stateStack[stackIndex][1], stateStack[stackIndex][2]];
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angle = stateStack[stackIndex][3];
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currentLineWidth = stateStack[stackIndex][4];
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strokeWeight(currentLineWidth);
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}
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// #: Increment the line width by line width increment
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function incrementLineWidth() {
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currentLineWidth += lineWidthIncrement;
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strokeWeight(currentLineWidth);
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}
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// !: Decrement the line width by line width increment
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function decrementLineWidth() {
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currentLineWidth -= lineWidthIncrement;
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strokeWeight(currentLineWidth);
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}
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// @: Draw a dot with line width radius
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function drawDot() {
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let x = currentPosition[0];
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let y = currentPosition[1];
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strokeWeight(currentWidth);
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strokeWeight(currentLineWidth);
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point(x, y);
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}
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function angleIncrement() {
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angle += turningAngleIncrement;
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// {: Open a polygon
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function openPolygon() {
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polygonVertices = [[currentPosition[0], currentPosition[1]]];
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polygonOpen = true;
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}
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function angleDecrement() {
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angle -= turningAngleIncrement;
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// }: Close a polygon and fill it with fill colour
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function closePolygon() {
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if (polygonOpen && polygonVertices.length > 2) {
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fill(100, 150, 255); // Default fill colour
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beginShape();
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for (let v of polygonVertices) {
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vertex(v[0], v[1]);
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}
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endShape(CLOSE);
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noFill(); // Reset to no fill
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}
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polygonVertices = [];
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polygonOpen = false;
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}
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// >: Multiply the line length by the line length scale factor
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function multiplyLineLength() {
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lineLength *= lineLengthScaleFactor;
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}
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// <: Divide the line length by the line length scale factor
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function divideLineLength() {
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lineLength /= lineLengthScaleFactor;
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}
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// &: Swap the meaning of + and -
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function swapPlusMinus() {
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swapPlusMinusState = !swapPlusMinusState;
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}
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// ): Increment turning angle by turning angle increment
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function incrementTurningAngle() {
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turningAngle += turningAngleIncrement;
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}
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// (: Decrement turning angle by turning angle increment
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function decrementTurningAngle() {
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turningAngle -= turningAngleIncrement;
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}
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function draw() {
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