MM Developer's Guide
MM Interfaces | MM Methods | MM Types and Misc API

IMoaMmXTransitionActor

Interface ID: IID_IMoaMmXTransitionActor
Pointer type: PIMoaMmXTransitionActor
Inheritance: IMoaUnknown
Header file: mmixasst.h

Methods

Asset interaction

Notify()

Performance

Cue()
Continue()
Finish()

Continue()

Syntax

Continue(PIMoaMmXTransitionActorThis,

PIMoaMmGCpDestGC,
PIMoaMmGCpSrcGC,
ConstPMoaRectpRect,
ConstPMoaMmTransInfopTransInfo,
MoaBoolParam FAR *pFinished)

Parameters

This

Pointer to the IMoaMmXTransitionActor interface

pDestGC

PIMoaMmGCPointer to an IMoaMmGC interface for the graphics context of the destination buffer or window.

pSrcGC

PIMoaMmGCPointer to an IMoaMmGC interface for the graphics context of the source buffer.

pRect

ConstPMoaRectPointer to a ConstPMoaRect describing the area to be transitioned.

pTransInfo

ConstPMoaMmTransInfoPointer to a ConstPMoaMmTransInfo structure containing values for the standard property settings

pFinished

MoaBoolParam FAR *Pointer to a MoaBoolParam, telling the host application whether or not your transition is complete.

Returns

kMoaErr_NoErr	Successful, transition serviced
kMoaMmErr_GCTypeNotSupported	Doesn't support supplied GC type
kMoaErr_OutOfMem	Couldn't service transition due to memory error
kMoaMmErr_InternalError	Couldn't service transition due to internal error

Description

Called when it's time to image more of the transition. This call occurs only after the IMoaMmXTransitionActor::Cue() method is called. If your transition is being stepped by the calling application, it can be interrupted by user action before your code has a chance to finish; in this case, the IMoaMmXTransitionActor::Finish() method gets called even if you did not set pFinished to TRUE in this call.

pDestGC is a pointer to an IMoaMmGC interface for the graphics context of the destination buffer or window. Typically, the graphics context corresponds to a native operating system window, but may be an offscreen buffer, for example, if the transition is rendered for export to digital video or other sequential image file. The destination graphics context is the one in which the transition is rendered or displayed. Upon calling Cue(), the destination graphics context contains the image from which to transition.

pSrcGC is a pointer to an IMoaMmGC interface for the graphics context of the source buffer. The source is never a window; it is always an offscreen buffer. The source graphics context is the one for the buffer containing the final image. The final image is displayed in the pDestGC graphics context after the transition is complete. If your transition effect requires access to the original image over the duration of the effect, you should copy the image in the destination graphics context to a private offscreen buffer in your Cue() method.

pRect is a pointer to a MoaRect describing the area to be transitioned. The same area applies to both the source and destination graphics contexts.

pTransInfo is a pointer to a structure containing values for the standard property settings, such as changeArea, chunkSize, duration, a flag indicating whether the transition should be performed in real-time, and the elapsed time since the start of the transition. The elapsed time is 0 when Cue() is called.

pFinished is a Boolean value indicating whether or not your transition is complete. When set to FALSE, it signifies that the transition is not yet complete and indicates that IMoaMmXTransitionActor::Continue() should be called again. When set to TRUE, it indicates that the transition has been completed; IMoaMmXTransitionActor::Continue() won't be called again, IMoaMmXTransitionActor::Finish() will be called next.

Cue()

Syntax

Cue(PIMoaMmXTransitionActorThis,

PIMoaMmGCpDestGC,
PIMoaMmGCpSrcGC,
ConstPMoaRectpRect,
ConstPMoaMmTransInfopTransInfo)

Parameters

This

Pointer to the IMoaMmXTransitionActor interface

pDestGC

PIMoaMmGCPointer to IMoaMmGC interface for destination buffer or window

pSrcGC

PIMoaMmGCPointer to IMoaMmGC interface for the source buffer

pRect

ConstPMoaRectPointer to a ConstPMoaRect for area to transition

pTransInfo

ConstPMoaMmTransInfoPointer to a ConstPMoaMmTransInfo structure containing values for standard property settings

Returns

kMoaErr_NoErr	Successful, ready to begin transition sequence
kMoaMmErr_GCTypeNotSupported	Doesn't support supplied GC type
kMoaErr_OutOfMem	Couldn't prepare for transition due to memory error
kMoaMmErr_InternalError	Couldn't prepare for transition due to internal error

Description

Called when the host application is preparing to perform a transition.

pDestGC is a pointer to an IMoaMmGC interface for the graphics context of the destination buffer or window. Typically, the graphics context corresponds to a native operating system window, but may be an offscreen buffer, for example, if the transition is rendered for export to digital video or other sequential image file. The destination graphics context is the one in which the transition is rendered or displayed. Upon calling Cue(), the destination graphics context contains the image from which to transition. Imaging should not occur while Cue() is invoked; the graphics contexts are supplied only for reference and preparation.

pSrcGC is a pointer to an IMoaMmGC interface for the graphics context of the source buffer. The source is never a window; it is always an offscreen buffer. The source graphics context is the one for the buffer containing the final image. The final image is displayed in the pDestGC graphics context after the transition is complete. If your transition effect requires access to the original image over the duration of the effect, you should copy the image in the destination graphics context to a private offscreen buffer in your Cue() method.

pRect is a pointer to a MoaRect describing the area to be transitioned. The same area applies to both the source and destination graphics contexts.

pTransInfo is a pointer to a structure containing values for the standard property settings, such as changeArea, chunkSize, duration, a flag indicating whether the transition should be performed in real-time, and the elapsed time since the start of the transition. The elapsed time is 0 when Cue() is called).

If the Cue routine returns kMoaErr_NoError, the Continue() method is called at least once, and the Finish() method is called after the Continue() method has signaled that the transition is complete.

If the Cue routine returns an error code, the Continue()and the Finish() methods are not called

Finish()

Syntax

Finish(PIMoaMmXTransitionActorThis,

PIMoaMmGCpDestGC,
PIMoaMmGCpSrcGC,
ConstPMoaRectpRect,
ConstPMoaMmTransInfopTransInfo)

Parameters

This

Pointer to the IMoaMmXTransitionActor interface

pDestGC

PIMoaMmGCPointer to IMoaMmGC interface for the destination buffer or window.

pSrcGC

PIMoaMmGCPointer to IMoaMmGC interface for the source buffer.

pRect

ConstPMoaRectPointer to a ConstPMoaRect for area to transition

pTransInfo

ConstPMoaMmTransInfoPointer to a ConstPMoaMmTransInfo structure containing values for the standard property settings

Returns

kMoaErr_NoErr

Successful, transition completed

Description

Called when the host has completed playing the transition. This call occurs only after the Cue() method has been called. If your transition is being stepped by the calling application it may have been interrupted by user action before finishing. In this case, the Finish() method is responsible for updating any parts of the destination graphics context with the final image from the source graphics context which did not get imaged.

pDestGC is a pointer to an IMoaMmGC interface for the graphics context of the destination buffer or window. Typically, the graphics context corresponds to a native operating system window, but may be an offscreen buffer, for example, if the transition is rendered for export to digital video or other sequential image file. The destination graphics context is the one in which the transition is rendered or displayed. Upon calling Cue(), the destination graphics context contains the image from which to transition. Imaging should not occur while Cue() is invoked; the graphics contexts are supplied only for reference and preparation.

pSrcGC is a pointer to an IMoaMmGC interface for the graphics context of the source buffer. The source is never a window; it is always an offscreen buffer. The source graphics context is the one for the buffer containing the final image. The final image is displayed in the pDestGC graphics context after the transition is complete. If your transition effect requires access to the original image over the duration of the effect, you should copy the image in the destination graphics context to a private offscreen buffer in your Cue() method.

pRect is a pointer to a MoaRect describing the area to be transitioned. The same area applies to both the source and destination graphics contexts.

pTransInfo is a pointer to a structure containing values for the standard property settings, such as changeArea, chunkSize, duration, a flag indicating whether the transition should be performed in real-time, and the elapsed time since the start of the transition. The elapsed time is 0 when Cue() is called).

Notify()

Syntax

Notify(PIMoaMmXTransitionActorThis,

MoaLongmsgCode,
PMoaVoidrefCon)

Parameters

This

Pointer to the IMoaMmXTransitionActor interface

msgCode

MoaLong

refCon

PMoaVoid

Returns

kMoaErr_NoErr	Successful
kMoaMmErr_UnknownNotifyMsgCode	Notify message code not supported

Description

Used for communicating between assets and their actors. Call this method from your implementation of the IMoaMmXAsset interface to notify an actor at any time. You defined the message codes used to pass messages from your asset to its actors. To call this method on all sprites, an asset can call IMoaMmAssetCallback::NotifySprites().

Note: Xtra developers may specify values in the range of 0 to 65535 for their notification codes. Higher values are reserved by Macromedia for future use.