public void mouseDragged(MouseEvent e) {
int x = e.getX();
int y = e.getY();
tmpMatrix.unit();
tmpMatrix.xrot(360.0 * (mouseY - y) / getSize().height);
tmpMatrix.yrot(360.0 * (x - mouseX) / getSize().width);
viewMatrix.mult(tmpMatrix);
repaint();
mouseX = x;
mouseY = y;
e.consume();
}
