This function queries a global named block for its data returning it in lpBlockData.

Declaration:

AT_ERRCOUNT ART_global_block_query(
        HIGEAR hIGear, 
        const LPART_BLOCK_NAME lpBlockName, 
        LPVOID lpBlockData, 
        LPDWORD lpBlockSize
);

Arguments:

Return Value:

Returns the number of ImageGear errors that occurred during the function call.

Supported Raster Image Formats:

All pixel formats supported by ImageGear for C and C++.

Sample:

None

Example:

HIGEAR hIGear; /* HIGEAR handle of image */
LPVOID blockData; /* data in global block  */
DWORD blockSize; /* size of block, in bytes */
AT_ERRCOUNT nErrCount; /* number of errors on the */
/* error stack  */
/* get the block size */
nErrCount = ART_global_block_query(hIGear, 
ART_BLOCK_GROUP, NULL, &blockSize);
blockData = (LPVOID)alloca(blockSize);
/* but the data into blockData */
nErrCount = ART_global_block_query(hIGear, 
ART_BLOCK_GROUP, blockData, &blockSize);

Remarks:

The buffer pointed to by lpBlockData must be large enough to fit the named block data. The size of the block is returned by lpBlockSize.

To find the size of a buffer necessary to hold the block data, call ART_global_block_query() with lpBlockData set to NULL. lpBlockSize returns the size of the block.

An error is set if any of the following conditions are met:

• hIGear does not reference a valid ImageGear handle.
• lpBlockName does not point to a valid address.
• lpBlockData does not point to a valid address or is not NULL.
• lpBlockData points to a buffer smaller than the block data.
• lpBlockSize points to an invalid address.
• lpBlockSize points to a value smaller than the size of the block data.