QuickTime 4 Reference

Transfer Component Flag Type

The gxComponentFlag type is used for transfer component flags.



 
typedef unsigned char   gxComponentFlag;

These flags, which are in the in the component field of the gxTransferComponent structure, alter the source, destination, or result value for an individual color component. For more information about the transfer modes for QuickTime vectors, see "Transfer Modes" .

The following transfer component flags are defined:

Constant	Value	Explanation
`gxOverResultComponent`	0x01	QuickDraw GX performs an AND operation between the result color and 0xFFFF before clamping.
`gxReverseComponent`	0x02	QuickDraw GX reverses the source and destination values before performing the transfer mode operation.

Specifying gxOverResultComponent allows the result of transfers using gxAddMode to wrap around (from 0xFFFF to 0x0000 ) instead of remaining clamped at 0xFFFF .

Specifying gxReverseComponent allows you to apply a transfer mode backwards--from the destination to the source--for a particular component. It is most useful for component modes that depend on order, like gxMigrateMode , or gxAddMode when used for subtraction.