void setup()
{
    size(800, 600);
    frameRate(60);
}
float second;
float offset = 0;

void draw()
{
    background(40, 40, 40, 256);
   //fill(0,0,0,1);
    second =  constrain(((float) frameCount / (float) frameRate) - offset, 0 , 1000);

    if(mousePressed == true)
    {
        offset = second + offset ;
    }

    println(offset + " " + mousePressed);
    textSize(50);
    text(second, width / 2 -50, height/2);
}