48

int numChecks = 25;
Check[]checks = new Check[numChecks];

void setup(){
size(100,100);
int x = 14;
int y = 14;
for(int i = 0; i < numChecks; i++){
checks[i] = new Check(x,y,12,color(0));
x += 15;
if(x > 80){
x = 14;
y += 15;
}
}
}

void draw(){
background(40);
for(int i =0; i < numChecks; i++){
checks[i].display();
}
}

void mousePressed(){
for(int i =0; i < numChecks; i++){
checks[i].press(mouseX,mouseY);
}
}

void keyPressed(){
if(key=='k'){
save("48.jpg");
}
}


class Check{
int x,y;
int size;
color baseGray;
boolean checked = false;

Check(int xp, int yp, int s, color b){
x = xp;
y = yp;
size = s;
baseGray = b;
}

void press(float mx, float my){
if((mx >= x)&&(mx <= x + size) && (my >= y)&&(my <= y+size)){
checked =!checked;
}
}

void display(){
stroke(255);
fill(baseGray);
rect(x,y,size,size);
if(checked == true){
line(x,y,x+size,y+size);
line(x+size,y,x,y+size);
}
}
}