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4 Programming (SDK)
401
4.5.17 is_LockDDOverlayMem
Syntax
INT is_LockDDOverlayMem(HIDS hCam, void** ppMem, INT* pPitch)
Description
Attention
This function is obsolete and should not be used anymore. We recommend to use the is_DirectRenderer()
function instead (see also Obsolete functions ).
In DirectDraw BackBuffer mode, is_LockDDOverlayMem() enables access to the overlay memory and returns
the pointer to the starting address of the overlay buffer. This way, you can write data directly to the overlay buffer
without the need to use the Windows GDI functions.
pPitch returns the line offset (in bytes) from the beginning of a line to the beginning of the next line. Make sure to
release the memory again as early as possible using the is_UnlockDDOverlayMem() function.
While a LockDDOverlayMem … UnlockDDOverlayMem block is executed, the contents of the overlay buffer will
not be refreshed on the screen.
Input parameters
Pointer to the variable that holds the address pointer
Pointer to the variable that holds the pitch value
Return values
Function executed successfully
Related functions
is_UnlockDDOverlayMem()
is_LockDDMem()
is_UnlockDDMem()
is_LockSeqBuf()
is_UnlockSeqBuf()
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