init'

tutorials/jarvisMarsh/sketch.js

@@ -0,0 +1,102 @@
+var jarvisMarsh = function( p ){
+
+	const numPoints = 12;
+	var vertices = [];
+	var route = [];
+	let iterations = 0;
+
+	p.setup = function(){
+		p.createCanvas(750, 500);
+		p.background(217);
+
+		button = p.createButton('Reset Button')
+		button.mousePressed(p.resetSketch);
+
+		p.initValues();
+
+	}
+
+	p.draw = function(){}
+
+
+	p.drawLine = function(){
+		let r = p.findLeftPoint();
+		route[iterations] = r;
+
+		p.findLeftLine(r);
+
+		p.stroke(215, 75, 75);
+		p.strokeWeight(1);
+		for (var i = 0; i < route.length - 1; i++){
+			p.line(vertices[route[i]].x, vertices[route[i]].y, vertices[route[i+1]].x, vertices[route[i+1]].y)
+		}
+	}
+
+	p.findLeftLine = function(originPoint){
+		var recordLeftVector = 1;
+		let x1, x2, y1, y2;
+
+		for (var i = 0; i < vertices.length; i++){
+			if (i != originPoint){
+				x1 = vertices[recordLeftVector].x - vertices[originPoint].x;
+				y1 = vertices[recordLeftVector].y - vertices[originPoint].y;
+
+
+
+				x2 = vertices[i].x - vertices[originPoint].x;
+				y2 = vertices[i].y - vertices[originPoint].y;
+
+				//if the result if positive then vector u is left of vector v
+				//where u and v are both vectors from the target point
+				//If its equal to 0 then they're colinear. This is also good :)
+				if ((y2 * x1) - (y1 * x2) <= 0){
+					recordLeftVector = i;
+				}
+
+			}
+		}
+
+		if (originPoint != recordLeftVector && iterations < 75){
+			route[iterations] = recordLeftVector;
+			iterations += 1;
+			p.findLeftLine(recordLeftVector);
+			
+		}
+	}
+
+	p.findLeftPoint = function(){
+		let recordLeft = 0;
+
+		for (var i = 0; i < vertices.length; i++){
+			if (vertices[i].x < vertices[recordLeft].x){
+				recordLeft = i;
+			}
+		}
+		return recordLeft;
+	}
+
+	p.resetSketch = function(){
+		vertices.length = 0;
+		p.clear()
+		p.background(217);
+		p.initValues();
+		p.findLeftLine();
+		p.draw();
+	}
+
+	p.initValues = function(){
+		p.stroke(0);
+		p.strokeWeight(7);
+
+		var bufferx = p.width * 0.0625;
+		var buffery = p.height * 0.0625; 
+
+		for (var i = 0; i < numPoints; i++){
+			vertices[i] = new dot(p.random(bufferx, p.width - bufferx), p.random(buffery, p.height - buffery));
+			p.point(vertices[i].x, vertices[i].y);
+		}
+		iterations = 0;
+		p.drawLine();
+	}
+};
+var myp5 = new p5(jarvisMarsh, 'c1');