Legacy Document

Inside Macintosh: Advanced Color Imaging Reference /

Chapter 3 - ColorSync Manager Reference for Applications and Device Drivers / ColorSync Manager Functions

Matching Colors Using Low-Level Functions Without QuickDraw /

CMGetCWInfo

Obtains information about the color management modules (CMMs) used for a specific color world.

pascal CMError CMGetCWInfo (
CMWorldRef cw,
CMCWInfoRecord *info);

cw

A reference to the color world (page 3-66) about which you want information.

info

A pointer to a color world information record (page 3-50) that your application supplies. On output, the ColorSync Manager returns information in this structure describing the number and kind of CMMs involved in the matching session and the CMM type and version of each CMM used.

function result

A result code of type CMError. See "Result Codes" (page 3-174) for a list of ColorSync-specific result codes.

DISCUSSION

To learn whether one or two CMMs are used for color matching and color checking in a given color world and to obtain the CMM type and version number of each CMM used, your application must first obtain a reference to the color world. To obtain a reference to a ColorSync color world, you must create the color world using the NCWNewColorWorld function or the CWConcatColorWorld function.

The source and destination profiles you specify when you create a color world identify their preferred CMMs, and you explicitly identify the profile whose CMM is used for a device-linked profile or a concatenated color world. However, you cannot be certain if the specified CMM will be used until the ColorSync Manager determines internally if the CMM is available and able to perform the requested function. For example, in some cases the default Apple CMM is used.

The CMGetCWInfo function identifies the CMM or CMMs to use. Your application must allocate a data structure of type CMCWInfoRecord and pass a pointer to it in the info parameter. The CMGetCWInfo function returns the color world information in this structure. The structure includes a cmmCount field identifying the number of CMMs to use and an array of two members containing structures of type CMMInfoRecord (page 3-51). The CMGetCWInfo function returns information in one or both of the CMM information records depending on whether one or two CMMs are used.

For a brief description of a color world, see "Matching Colors Using Low-Level Functions Without QuickDraw" (page 3-107).

SEE ALSO

The NCWNewColorWorld function (page 3-108) and the CWConcatColorWorld function (page 3-110) both allocate color world references of type CMWorldRef.