voronoi ?

openframworks.cpp

	// create cells with random positions and colors
	for (auto i = 0; i < 2000; i++) {
		Cell cell;
		cell.position.x = ofRandom(0, ofGetWidth());
		cell.position.y = ofRandom(0, ofGetHeight());
		cell.color = ofColor(ofRandom(0, 255), ofRandom(0, 255), ofRandom(0, 255));
		cells.push_back(cell);
	}

	
	// loop through all the cells and compare them to each other to see if they are close enough to change color
	// effectively, this creates a "neighborhood" of cells that are close to each other
	for (auto &cell : cells) {
		for (auto &otherCell : cells) {
			if (&cell != &otherCell) {
				float distance = ofDist(cell.position.x, cell.position.y, otherCell.position.x, otherCell.position.y);
				if (distance < 100) {
					cell.color = otherCell.color;
				}
			}
		}
	}