// sketch.js
var xC; // orbit center
var yC;
var rV = 120; // orbit radius Venus
var rE = 180; // orbit radius Earth
var aV; // angle Venus
var aE; // angle Earth
var xV; var yV; // coord venus
var xE; var yE; // coord Earth
function setup() {
var cnv = createCanvas(640, 400);
cnv.position(24, 140);
background(0, 0, 255);
xC = width/2;
yC = height/2;
aV = -PI/2;
aE = -PI/2;
ellipseMode(RADIUS);
} //setup
function draw() {
background(0, 0, 255);
drawCentralPoint();
drawOrbits();
aV = aV + PI/40;
aE = aE + PI/60;
drawVenus();
drawEarth();
} //draw
function drawCentralPoint() {
strokeWeight(3);
point(xC, yC);
} //drawCentralPoint
function drawOrbits() {
strokeWeight(1);
fill(0, 0, 0, 0);
ellipse(xC, yC, rV, rV);
ellipse(xC, yC, rE, rE);
} //drawOrbits
function drawVenus() {
xV = xC + rV*cos(aV);
yV = yC + rV*sin(aV);
fill(255, 0, 255);
ellipse(xV, yV, 7, 7);
} //drawVenus
function drawEarth() {
xE = xC + rE*cos(aE);
yE = yC + rE*sin(aE);
fill(0, 255, 255);
ellipse(xE, yE, 7, 7);
} //drawEarth