KnowledgeBase Archive

An Archive of Early Microsoft KnowledgeBase Articles

View on GitHub

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.

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.