Section Header
    + name := AREA_MASK;
    - comment := "Mask Window Clipping.";
    - version := 2;
Section Inherit
    + parent_area:Expanded AREA;
Section Public
    + mask:FAST_ARRAY[FAST_ARRAY[UINTEGER_16]];
    - clear_mask <-
Creation
    - make father:AREA from (x0,y0:INTEGER) size (w,h:INTEGER) <-
    - resize (lx,ly:INTEGER) <-
Master display
(Build mask)
    - pixel_hard (x,y:INTEGER) color col:UINTEGER_32 <-
    - line_h_hard (x1,y:INTEGER) until x2:INTEGER color col:UINTEGER_32 <-
    - line_h_hard (x1,y:INTEGER) until x2:INTEGER image line:ABSTRACT_BMP_LINE offset ofs:INTEGER <-
Slave display
(Use Mask)
    - slave_pixel_hard (x,y:INTEGER) color col:UINTEGER_32 <-
    - slave_line_h_hard (x1,y:INTEGER) until x2:INTEGER color col:UINTEGER_32 <-
    - slave_line_h_hard (x1,y:INTEGER) until x2:INTEGER image line:ABSTRACT_BMP_LINE offset ofs:INTEGER <-
    - mask_draw (x0,y0:INTEGER) to (x1,y1:INTEGER) color col:UINTEGER_32 <-