code: private void updateCoordinates() {
      // Top-left of heat map.
      int x = margin + axisThickness + yAxisLabelSize.height;
      x += (yValuesHorizontal ? yAxisValuesWidthMax : yAxisValuesHeight);
      int y = titleSize.height + margin;
      heatMapTL = new Point(x, y);
  
      // Top-right of heat map.
      x = heatMapTL.x + heatMapSize.width;
      y = heatMapTL.y + heatMapSize.height;
      heatMapBR = new Point(x, y);
  
      // Centre of heat map.
      x = heatMapTL.x + (heatMapSize.width / 2);
      y = heatMapTL.y + (heatMapSize.height / 2);
      heatMapC = new Point(x, y);
    }
docs: /*
  Calculates the co-ordinates of some key positions.