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Q77934: Determining That Display Driver Supports Transparent Mode

Article: Q77934
Product(s): Microsoft Windows Software Development Kit
Version(s): WINDOWS:3.0,3.1
Operating System(s): 
Keyword(s): kb16bitonly
Last Modified: 12-NOV-1999

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The information in this article applies to:

- Microsoft Windows Software Development Kit (SDK) versions 3.0, 3.1 
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SUMMARY
=======

In some display drivers compatible with Microsoft Windows, the BitBlt and
StretchBlt functions support transparent mode. Before using this feature, an
application must determine whether the display driver supports this mode by
calling the GetDeviceCaps function.

MORE INFORMATION
================

Two of the multimedia display drivers, MMV7VGA.DRV and MMWD480.DRV, support
transparent mode. When using GetDeviceCaps to determine the capabilities of
these drivers, it is common to use the RASTERCAPS index. However, to determine
if transparent mode is supported, an application must use the CAPS1 index.

Use the bitwise AND operator with C1_TRANSPARENT mask to determine if the
appropriate bit is set; if it is, the driver supports transparent mode. The
following code fragment demonstrates this test:

     bTransSupport = (GetDeviceCaps(hDC, CAPS1) & C1_TRANSPARENT)
                      ? TRUE : FALSE;

Additional query words: 3.00 3.10 no32bit

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Keywords          : kb16bitonly 
Technology        : kbAudDeveloper kbWin3xSearch kbSDKSearch kbWinSDKSearch kbWinSDK300 kbWinSDK310
Version           : WINDOWS:3.0,3.1

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