Draw a golden spiral with Processing

goldenSpiral.pde

float PHI = (1 + sqrt(5)) / 2;

void goldenSpiral(float h) {
	// Base case: stop drawing if the height is too small.
	if (h < 2) {
		return;
	}

	// Draw bounding box and quarter circle.  For some reason, using 2 * h - 1
	// looks better than using 2 * h.
	rect(0, 0, h, h);
	arc(h, h, 2 * h - 1, 2 * h - 1, PI, PI + HALF_PI);

	// Reposition canvas for next iteration.
	translate(h * PHI, 0);
	rotate(HALF_PI);

	// Perform recursive call (with height scaled down by golden ratio).
	goldenSpiral(h / PHI);
}

void setup() {
	// 500 * PHI is approximately 809.  We add an additional 100 to the width
	// and height to account for margins.
	size(909, 600);
	
	background(255);   // Set a white background.
	translate(50, 50); // Add margins.
	noFill();          // Draw outlines only.

	goldenSpiral(500);
	save("goldenSpiral.png");
}

goldenSpiral.png

This was inspired by https://thirdfoundation.github.io/#/art/pyramids