colorMode(HSB);

var nodeCount = 360;
var friendCount = 2;
var centerX = 200;
var centerY = 200;
var radius = 198;

var coordsOfPoint = function(ptNum) {
    var theta = map(ptNum, 0, nodeCount-1, 0, 360);
    return new PVector(centerX + radius*cos(theta), centerY + radius*sin(theta));
};

var coords = [];

for(var i = 0; i < nodeCount; i++) {
    coords[i] = coordsOfPoint(i);
}

background(255, 0, 255);
var draw = function() {
    if(frameCount >= nodeCount) {
        //return;
        frameCount = frameCount % nodeCount;
    }
    
    // draw friends
    for(var j = 0; j < friendCount; j++) {
        var friend = (frameCount + floor(nodeCount/(friendCount+1))*(j+1)) % nodeCount;
        strokeWeight(1);
        stroke(map(friend, 0, nodeCount-1, 0, 255), 255, 255, 100);
        //stroke(map(frameCount, 0, nodeCount-1, 0, 255), 255, 255);
        line(coords[frameCount].x, coords[frameCount].y, coords[friend].x, coords[friend].y); // coords[0].y
    }
    
    // draw point
    stroke(0, 0, 0);
    strokeWeight(3);
    point(coords[frameCount].x, coords[frameCount].y);
};