final int repaintRectWidth = 5 * this.pointsAdded;
backBufferGc.copyArea(repaintRectWidth, 0, clientArea.width
- repaintRectWidth, clientArea.height, 0, 0, false);
backBufferGc.fillRectangle(clientArea.width - repaintRectWidth, 0,
repaintRectWidth, clientArea.height);
frontGc.drawImage(this.backBuffer, 0, 0);
backBufferGc.dispose();
this.redraw(clientArea.width - repaintRectWidth, 0, repaintRectWidth,
clientArea.height, false);
this.pointsAdded = 0;