Gradient interpolation with 3+ points

Processing Coding Questions
3

Ok here is my version, the rect() bit is probably not the best, also it doesn’t look at smooth as I expected.

PVector[] points = new PVector[4];
PVector[] cols = new PVector[4];

void setup() {
	size(200, 200);
	background(100);
	frameRate(1);
	noLoop();
  points[0] = new PVector(50, 50);
  points[1] = new PVector(20, 20);
  points[2] = new PVector(80, 60);
  points[3] = new PVector(120, 120);
  cols[0] = new PVector(255, 100, 100);
  cols[1] = new PVector(200, 255, 100);
  cols[2] = new PVector(0, 100, 200);								
  cols[3] = new PVector(50, 0, 200);                
}

void draw() {
	// ellipse(mouseX, mouseY, 20, 20);
	for (int x = 0; x < width; x += 1) {
		for (int y = 0; y < height; y += 1) {
			PVector rgb = new PVector(0, 0, 0);
			float d_total = 0;
			for (int i = 0; i < points.length; i++) {
				// weight by inverse distance, avoid div by 0
				float d = 100 / (dist(x, y, points[i].x, points[i].y) + random(-0.001, .001));
        PVector incr = PVector.mult(cols[i], d);
        // rgb.add(cols[i]);
				rgb.add(incr);
				d_total += d;
			}
			rgb.div(d_total);
      // rgb.div(points.length);
      noStroke();
			fill(rgb.x, rgb.y, rgb.z);
			rect(x, y, 1, 1);
		}
	}
       filter(BLUR, 5);
}