int fps = 60;
//...lots of rendering
//..
//..
t1 = system.nanoTime();
long delta = ((1E+9)*1.0/fps) - (t1-t0);
t0 = system.nanoTime();
g.drawString("FPS:"+ (1E+9)*1.0/delta, 0,0);
buffer.show();
//Sleep
Thread.sleep(delta)

public void fire()
{
    // quadratic equation for the time taken for the bullet to hit the target: a*t^2 + b*t + c = 0, where:
    double a = targetVelX*targetVelX + targetVelY*targetVelY - BULLET_SPEED*BULLET_SPEED;

    double b = 2*targetVelX*(targetX-bulletX) + 2*targetVelY*(targetY-bulletY);

    double c = (targetX-bulletX)*(targetX-bulletX) + (targetY-bulletY)*(targetY-bulletY);

    // discriminant of the quadratic formula
    double disc = b*b - 4*a*c;
    if (disc>=0){ // the bullet can't hit the target if the discriminant is negative
        double q = (b + Math.signum(b)*Math.sqrt(disc))/-2.0;
        double t1 = q/a;
        double t2 = c/q;
        double t = 0; //will be set later
        if (t1>=0 && t2>=0)// both positive
            t = math.min(t1,t2);
        else if (t1>=0)// only t1 positive
            t = t1;
        else if (t2>=0)// only t2 positive
            t = t2;
        else // both negative
            return; // the target cannot be hit. might want to do something else here as well/instead.
        
        bulletVelX = targetVelX + (targetX - bulletX)/t;
        bulletVelY = targetVelY + (targetY - bulletY)/t;
    }
}

    globalPush = globalPushMult*(random.random() - 0.5)
    
    for i in range(0,len(xpos)):
        pygame.draw.circle(windowSurfaceObj, clrWhite, (int(xpos[i]), int(ypos[i])), 2, 0)
        xpos[i]+=xvel[i]
        ypos[i]+=yvel[i]
        
        xvel[i]+=globalPush+xPushMult*(random.random()-0.5)
        xvel[i]*=frictionMult

AffineTransform identity = new AffineTransform();

g2d.translate(-viewX, -viewY);

//
//rendering code here
//

g2d.setTransform(identity);

viewX = charX - screenWidth/2;
viewY = charY - screenHeight/2;

java Zip2Gzip b.proguard.kz.pack b.proguard.kz.pack.gz