public void processKeyboard() {
       boolean xSpeedCap = (+xvel < (Keyboard.isKeyDown(Keyboard.KEY_Z)? targetXSpeed_running : targetXSpeed));

        if (Keyboard.isKeyDown(Keyboard.KEY_RIGHT)) {
            if (grounded) {
                if (xSpeedCap) {
                    xvel += xAcceleration;
                }
            }
        }

        if (Keyboard.isKeyDown(Keyboard.KEY_LEFT)) {
            if (grounded) {
                if (xSpeedCap) {
                    xvel -= xAcceleration;
                }
            }
        }

        if (Keyboard.isKeyDown(Keyboard.KEY_X)) {
            if (grounded == true) {
                yvel += jumpForce;
            }
        }
    }