using a simplified version of java to write a code to make black balls turn red and connected by a line, which is all reset by keypress

float x = 150;
float y = 200;
int red = 0;

void setup() {
size(300, 400);
background(80, 255, 80);
fill(255, 0, 0);
ellipse(150, 200, 50, 50);
}

void mousePressed() {
noLoop();
x = ((x + mouseX) /2);
y = ((y + mouseY) /2);
loop();
}
void draw() {

if (mousePressed == true) {
red = 0;
}
red = red + 10;
fill(red, 0, 0);
ellipse(x, y, 50, 50);
}

please someone help. lol. i get the feeling i have made it needlessly complicated but i dont know how to simplify it, also working on the connecting lines and reset now but my format makes it hard to include the information.

made some progress, should be easier to read now

final int DIA = 50;
float circleX = 150;
float circleY = 200;
float lineX, lineY;
int RED = 0;

void setup() {
size(300, 400);
background(80, 255, 80);
fill(255, 0, 0);
ellipse(150, 200, DIA, DIA); // DIA is constant
strokeWeight(1);
}

void draw() {
if (mousePressed == true) // pressing mouse resets colour to black
RED = 0;
RED = RED + 10;
strokeWeight(2);
line(circleX, circleY, lineX, lineY);
strokeWeight(1);
fill(RED, 0, 0); // (0, 0, 0) approaches (255, 0, 0)
ellipse(circleX, circleY, DIA, DIA);
}

void mousePressed() {
circleX = (circleX + mouseX) /2; // midpoint of circleX and mouseX
circleY = (circleY + mouseY) /2; // midpoint of circleY and mouseY
}

i need to draw a line from circleX/Y to the previous circleX/Y

but i have no idea what i need to do in order to find the coordinates of the previous circle

i need to draw the line before the circle so the final circle appear on top of the line

if you know there are exactly two circles, just add more variables. eg circle2x and circle2y

if there are more than two, create an array. every time you draw a circle, queue up your points