Q39215: Pattern Format for _setfillmask

Article: Q39215
Product(s): See article
Version(s): 5.00 5.10
Operating System(s): MS-DOS
Keyword(s): ENDUSER | _getfillmask | mspl13_c
Last Modified: 29-DEC-1988

The _setfillmask function sets a background pattern using repeated
8-by-8 pixel patterns. The mask consists of an 8-byte character array.

The following example illustrates a pixel pattern:

                         Powers of 2

    decimal:   128  64  32  16  08  04  02  01
        hex:    80  40  20  10  08  04  02  01
               --------------------------------
       byte 1 |      1   1           1   1        =   0x66
       byte 2 |      1   1           1   1        =   0x66
       byte 3 |                                   =   0x00
       byte 4 |                  1                =   0x08
       byte 5 |              1   1                =   0x18
       byte 6 |  1                           1    =   0x81
       byte 7 |      1                   1        =   0x42
       byte 8 |          1   1   1   1            =   0x3C

The character array for this particular fill mask would be declared in
a C program as follows:

   unsigned char *maskarray = "\x66\x66\x00\x08\x18\x81\x42\x3C";

When the fill mask above is used with _setfillmask and a graphics
function such as _rectangle or _ellipse, the pattern will create
a continuous field of faces.