I call mine CirclesFollow. I set out to code something that can write words with circles; I find circles to be aesthetically pleasing. So, first I made the background a deep blue, to provide contrast to the circles. I had a triangle of a lighter blue in the background, with the alpha value so it would be more transparent, letting the background show through.  My loop created faint yellow lines along the triangle and the background. With the movement of the mouse, circle trail in random sizes and colors, but all with transparency ; I use this to write out words as “hello” and such. But, when you press the mouse, the circles are suddenly joined by various rectangles in random colors. I like the idea of surprise; so the obtrusive rectangles contrasting the softer background and the circles I find interesting. From the first attempt, I added transparency to the shapes, finally figured out how to center the triangle, added the mouse interaction, and included a loop.

 

 

My Code:

int CIRCLES = 0;

void setup() {
size (900, 600);
background(3, 24, 59);
fill( 128, 243, 255, 50);
stroke(CIRCLES + 128, 243, 255, 50);
strokeWeight(3);
triangle(100, 500, 800, 500, 450, 10);
for ( int o = 0; o < 900; o = o+2) {
for (int k = 0; k<900; k= k+5) {
stroke(225, 243, 0, 5);
point (o, k);
}
}
}

void draw() {
stroke(random(CIRCLES, 225), random(CIRCLES, 225), random(CIRCLES, 225));
strokeWeight(1);
fill(random(CIRCLES, 225), random(CIRCLES, 255), random(CIRCLES, 255), 110);
ellipse(mouseX, mouseY, random(30), random(30));
if (mousePressed) {
stroke(random(CIRCLES, 41), random(CIRCLES, 225), random(CIRCLES, 80));
strokeWeight( random ( CIRCLES, 10));
fill(random(CIRCLES, 225), random(CIRCLES, 255), random(CIRCLES, 255));
rect(mouseX, mouseY, random( 0, 50), random( 0, 100));
}
}