procedure DrawPolygon_ClearType(img: TImage32; const polygons: TPathsD; fillRule: TFillRule; color: TColor32; backColor: TColor32 = clWhite32);

This function is used almost exclusively when rendering text on relatively low resolution displays. Text rendering with smaller fonts on low resolution monitors can be blurry, and 'Clear Type' (also known as Subpixel rendering) can improve text clarity. 'Clear Type' rendering is of little or no benefit when displaying text in larger fonts and on high resolution displays, and will only compromise performance.