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CMMGetPS2ColorRenderingIntent |
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Header: | CMMComponent.h | Carbon status: | Unsupported | |
Handles the kCMMGetPS2ColorRenderingIntent request by obtaining the rendering intent from the source profile.
CMError CMMGetPS2ColorRenderingIntent ( CMMComponentInst cmm, CMProfileRef srcProf, UInt32 flags, CMFlattenUPP proc, void *refCon );
A handle to your CMMs storage for the instance of your component associated with the calling application or device driver.
A profile reference to the source profile whose header contains the rendering intent.
Reserved for future use.
A pointer to a function supplied by the calling application or device driver. Your CMMGetPS2ColorRenderingIntent function calls this function repeatedly as necessary until you have passed all the source profiles rendering intent data to this function.
A reference constant, containing data specified by the calling application or device driver, that your CMMGetPS2ColorRenderingIntent function must pass to the CMFlattenProcPtr function.
A CMM may respond to the kCMMGetPS2ColorRenderingIntent request code, but it is not required to do so. The ColorSync Manager sends this request code to your CMM on behalf of an application that called the CMGetPS2ColorRenderingIntent function. The ColorSync Manager dispatches this request to the Component Manager, which calls your CMM to service the request. A CMM typically responds to the kCMMGetPS2ColorRenderingIntent request code by calling a CMM-defined function (for example, CMMGetPS2ColorRenderingIntent) to handle the request.
Only for special cases should a custom CMM need to support this request code. If your CMM supports this function, your CMMGetPS2ColorRenderingIntent function must obtain the rendering intent from the source profile whose reference is passed to your function in the srcProf parameter. The byte stream containing the rendering intent data that your function passes to the CMFlattenProcPtr function is used as the operand to the PostScript findRenderingIntent operator.
Your function must allocate a data buffer in which to pass the rendering intent data to the CMFlattenProcPtr function supplied by the calling application or driver. Your CMMGetPS2ColorRenderingIntent function must call the CMFlattenProcPtr function repeatedly until you have passed all the data to it.
Your CMMGetPS2ColorRenderingIntent function communicates with the CMFlattenProcPtr function using a command parameter to identify the operation to perform. Your function should call the CMFlattenProcPtr function first with the cmOpenWriteSpool command to direct the CMFlattenProcPtr function to begin the process of writing the profile color-rendering intent element data you pass it in the data buffer. Next, you should call the CMFlattenProcPtr function with the cmWriteSpool command. After the CMFlattenProcPtr function returns in the size parameter the amount of data it actually read, you should call the CMFlattenProcPtr function again with the cmWriteSpool command, repeating this process as often as necessary until all the color-rendering intent data is transferred. After the data is transferred, you should call the CMFlattenProcPtr function with the cmCloseSpool command.
When your function calls the CMFlattenProcPtr function, it passes in the data buffer the profile data to transfer to the CMFlattenProcPtr function and the size in bytes of the buffered data in the size parameter. The CMFlattenProcPtr function may not always write all the data you pass it in the data buffer. Therefore, on return the CMFlattenProcPtr function command passes back in the size parameter the number of bytes it actually wrote. Your CMMGetPS2ColorRenderingIntent function keeps track of the number of bytes of remaining color-rendering intent element data.
Each time your CMMGetPS2ColorRenderingIntent function calls the CMFlattenProcPtr function, you pass it the reference constant passed to your function in the reference constant parameter.
For information about PostScript operations, see the PostScript Language Manual, second edition.
CMMGetPS2ColorRenderingIntent is an API to CMMs. Use CMGetPS2ColorRenderingIntent instead. Application developers should avoid calling CMMs directly, since they may or may not support a given API.
© 2000 Apple Computer, Inc. (Last Updated 7/17/2000)