BUG: Patterned Flood Fill Locks Machine or Draws Incorrectly

The information in this article applies to:

• The C Run-time (CRT), included with:

      - Microsoft C/C++ for MS-DOS, version 7.0
      - Microsoft Visual C++ for Windows, versions 1.0 and 1.5
  

SYMPTOMS

When the GRAPHICS.LIB function _setfillmask() is used to specify a patterned fill region in an MS-DOS application, _floodfill() or _floodfill_w() may not fill the region as expected. Either a patterned area is drawn outside of the enclosed region or the application hangs before the region to be painted is completely filled.

STATUS

Microsoft has confirmed this to be a bug in Microsoft C/C++ for MS-DOS, version 7.0, and Microsoft Visual C++ for Windows, versions 1.0 and 1.5. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

This is not an issue with Visual C++ for Windows NT, because GRAPHICS.LIB is strictly an MS-DOS library.

MORE INFORMATION

This sample code illustrates the problem:

Sample Code

/* Compile options needed: none
*/

   #include <graph.h>

   void main()
   {
      unsigned char small_dots[8] =
      {
         0x88, 0x22, 0x88, 0x22,
         0x88, 0x22, 0x88, 0x22
      };
      _setvideomode(_VRES16COLOR);
      _setfillmask(small_dots);               /* solid fill works fine */
      _rectangle(_GBORDER, 10, 61, 300, 341);
      _rectangle(_GBORDER, 20, 71, 290, 338);
      _floodfill(12, 260, _getcolor());       /* hangs here */
      _setvideomode(_DEFAULTMODE);
   }