inG.fillRect(0, 0, width, height);
if (width < 2*BORDER_WIDTH || height < 2*BORDER_WIDTH) return;
// blank graph area, with line border
inG.fillRect(0, 0, width, height);
if (width < 2*BORDER_WIDTH || height < 2*BORDER_WIDTH) return;
// blank graph area, with line border