ID Number: Q77934
1.00
WINDOWS
Summary:
In some display drivers compatible with Microsoft Multimedia 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 reference words: 1.00