DW      FILLSTYLE       ; Set the filling pattern

  Input:
     AL         Primary fill pattern number
     ES:BX      If the pattern number is 0FFh, this points to user define
                pattern mask.

  Return:
     Nothing


Sets the fill pattern for drawing. The fill pattern is used to fill all
bounded regions (BAR, POLY, and PIESLICE). The numbers for the
predefined fill patterns are as follows:

Code    Description                     8 Byte fill pattern

  0       No Fill          000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
  1       Solid Fill       0FFh, 0FFh, 0FFh, 0FFh, 0FFh, 0FFh, 0FFh, 0FFh
  2       Line Fill        0FFh, 0FFh, 000h, 000h, 0FFh, 0FFh, 000h, 000h
  3       Lt Slash Fill    001h, 002h, 004h, 008h, 010h, 020h, 040h, 080h
  4       Slash Fill       0E0h, 0C1h, 083h, 007h, 00Eh, 01Ch, 038h, 070h
  5       Backslash Fill   0F0h, 078h, 03Ch, 01Eh, 00Fh, 087h, 0C3h, 0E1h
  6       Lt Bkslash Fill  0A5h, 0D2h, 069h, 0B4h, 05Ah, 02Dh, 096h, 04Bh
  7       Hatch Fill       0FFh, 088h, 088h, 088h, 0FFh, 088h, 088h, 088h
  8       XHatch Fill      081h, 042h, 024h, 018h, 018h, 024h, 042h, 081h
  9       Interleave Fill  0CCh, 033h, 0CCh, 033h, 0CCh, 033h, 0CCh, 033h
 10       Wide Dot Fill    080h, 000h, 008h, 000h, 080h, 000h, 008h, 000h
 11       Close Dot Fill   088h, 000h, 022h, 000h, 088h, 000h, 022h, 000h

 0FFh     User is defining the pattern of the fill.

In the case of a user-defined fill pattern, the register pair ES:BX point
to 8 bytes of data arranged as a 8x8 bit pattern to be used for the fill
pattern.