All image effect plug-ins have a main entry point. This is used to trap all the standard actions used to drive the plug-in. They can also have other optional
entry points that allow the plug-in to create custom user interface widgets. These interact entry points are specified during the
two description actions.
The following actions can be passed to a plug-in's main entry point...
- The Generic Load Action called just after a plug-in is first loaded,
- The Generic Unload Action called just before a plug-in is unloaded,
- The Generic Describe Action called to describe a plug-in's behaviour to a host,
- The Generic Create Instance Action called just after an instance is created,
- The Generic Destroy Instance Action called just before an instance is destroyed,
- The Generic Begin/End Instance Changed Actions, a pair of actions used to bracket a set of Instance Changed actions,
- The Generic Instance Changed Action an action used to indicate that a value has changed in a plug-in instance,
- The Generic Purge Caches Action> called to have the plug-in delete any temporary private data caches it may have,
- The Sync Private Data Action called to have the plug-in sync any private state data back to its data set,
- The Generic Begin/End Instance Edit Actions a pair of calls that are used to bracket the fact that a user interface has been opened on an instance and it is being edited,
- The Begin Sequence Render Action where a plug-in is told that it is about to render a sequence of images,
- The Render Action where a plug-in is told that it is to render an output image,
- The End Sequence Render Action where a plug-in is told it has finished rendering a sequence of images,
- The Describe In Context Action used to have a plug-in describe itself in a specific context,
- The Get Region of Definition Action where an instance gets to state how big an image it can create,
- The Get Regions Of Interest Action where an instance gets to state how much of its input images it needs to create a give output image,
- The Get Frames Needed Action where an instance gets to state how many frames of input it needs on a given clip to generate a single frame of output,
- The Is Identity Action where an instance gets to state that its current state does not affect its inputs, so that the output can be directly copied from an input clip,
- The Get Clip Preferences Action where an instance gets to state what data and pixel types it wants on its inputs and will generate on its outputs,
- The Get Time Domain Action where a plug-in gets to state how many frames of data it can generate.