File ofxInteract.h

Contains the API for ofx plugin defined GUIs and interaction.

Defines

kOfxInteractSuite
kOfxInteractPropSlaveToParam

The set of parameters on which a value change will trigger a redraw for an interact.

  • Type - string X N

  • Property Set - interact instance property (read/write)

  • Default - no values set

  • Valid Values - the name of any parameter associated with this interact.

If the interact is representing the state of some set of OFX parameters, then is will need to be redrawn if any of those parameters’ values change. This multi-dimensional property links such parameters to the interact.

The interact can be slaved to multiple parameters (setting index 0, then index 1 etc…)

kOfxInteractPropPixelScale

The size of a real screen pixel under the interact’s canonical projection.

  • Type - double X 2

  • Property Set - interact instance and actions (read only)

kOfxInteractPropBackgroundColour

The background colour of the application behind an interact instance.

  • Type - double X 3

  • Property Set - read only on the interact instance and in argument to the kOfxInteractActionDraw action

  • Valid Values - from 0 to 1

The components are in the order red, green then blue.

kOfxInteractPropSuggestedColour

The suggested colour to draw a widget in an interact, typically for overlays.

  • Type - double X 3

  • Property Set - read only on the interact instance

  • Default - 1.0

  • Valid Values - greater than or equal to 0.0

Some applications allow the user to specify colours of any overlay via a colour picker, this property represents the value of that colour. Plugins are at liberty to use this or not when they draw an overlay.

If a host does not support such a colour, it should return kOfxStatReplyDefault

kOfxInteractPropPenPosition

The position of the pen in an interact.

This value passes the postion of the pen into an interact. This is in the interact’s canonical coordinates.

kOfxInteractPropPenViewportPosition

The position of the pen in an interact in viewport coordinates.

This value passes the postion of the pen into an interact. This is in the interact’s openGL viewport coordinates, with 0,0 being at the bottom left.

kOfxInteractPropPenPressure

The pressure of the pen in an interact.

This is used to indicate the status of the ‘pen’ in an interact. If a pen has only two states (eg: a mouse button), these should map to 0.0 and 1.0.

kOfxInteractPropBitDepth

Indicates whether the dits per component in the interact’s openGL frame buffer.

  • Type - int X 1

  • Property Set - interact instance and descriptor (read only)

kOfxInteractPropHasAlpha

Indicates whether the interact’s frame buffer has an alpha component or not.

  • Type - int X 1

  • Property Set - interact instance and descriptor (read only)

  • Valid Values - This must be one of

    • 0 indicates no alpha component

    • 1 indicates an alpha component

kOfxActionDescribeInteract

This action is the first action passed to an interact. It is where an interact defines how it behaves and the resources it needs to function. If not trapped, the default action is for the host to carry on as normal Note that the handle passed in acts as a descriptor for, rather than an instance of the interact.

Parameters:

  • handle – handle to the interact descriptor, cast to an OfxInteractHandle

  • inArgs – is redundant and is set to NULL

  • outArgs – is redundant and is set to NULL

Pre:

  • The plugin has been loaded and the effect described.

Returns:

kOfxActionCreateInstanceInteract

This action is the first action passed to an interact instance after its creation. It is there to allow a plugin to create any per-instance data structures it may need.

Parameters:

  • handle – handle to the interact instance, cast to an OfxInteractHandle

  • inArgs – is redundant and is set to NULL

  • outArgs – is redundant and is set to NULL

Pre:

Post:

  • the instance pointer will be valid until the kOfxActionDestroyInstance action is passed to the plug-in with the same instance handle

Returns:

kOfxActionDestroyInstanceInteract

This action is the last passed to an interact’s instance before its destruction. It is there to allow a plugin to destroy any per-instance data structures it may have created.

Parameters:

  • handle – handle to the interact instance, cast to an OfxInteractHandle

  • inArgs – is redundant and is set to NULL

  • outArgs – is redundant and is set to NULL

Pre:

Post:

  • the instance pointer is no longer valid and any operation on it will be undefined

Returns:

To some extent, what is returned is moot, a bit like throwing an exception in a C++ destructor, so the host should continue destruction of the instance regardless

kOfxInteractActionDraw

This action is issued to an interact whenever the host needs the plugin to redraw the given interact.

The interact should either issue OpenGL calls to draw itself, or use DrawSuite calls.

If this is called via kOfxImageEffectPluginPropOverlayInteractV2, drawing MUST use DrawSuite.

If this is called via kOfxImageEffectPluginPropOverlayInteractV1, drawing SHOULD use OpenGL. Some existing plugins may use DrawSuite via kOfxImageEffectPluginPropOverlayInteractV1 if it’s supported by the host, but this is discouraged.

Note that the interact may (in the case of custom parameter GUIS) or may not (in the case of image effect overlays) be required to swap buffers, that is up to the kind of interact.

Parameters:
Pre:

  • kOfxActionCreateInstance has been called on the instance handle

  • the openGL context for this interact has been set

  • the projection matrix will correspond to the interact’s cannonical view

Returns:

kOfxInteractActionPenMotion

This action is issued whenever the pen moves an the interact’s has focus. It should be issued whether the pen is currently up or down. No openGL calls should be issued by the plug-in during this action.

Parameters:
Pre:

Post:

  • if the instance returns kOfxStatOK the host should not pass the pen motion to any other interactive object it may own that shares the same view.

Returns:

  • kOfxStatOK the action was trapped and the host should not pass the event to other objects it may own

  • kOfxStatReplyDefault the action was not trapped and the host can deal with it if it wants

kOfxInteractActionPenDown

This action is issued when a pen transitions for the ‘up’ to the ‘down’ state. No openGL calls should be issued by the plug-in during this action.

Parameters:
Pre:

Post:

  • if the instance returns kOfxStatOK, the host should not pass the pen motion to any other interactive object it may own that shares the same view.

Returns:

  • kOfxStatOK, the action was trapped and the host should not pass the event to other objects it may own

  • kOfxStatReplyDefault , the action was not trapped and the host can deal with it if it wants

kOfxInteractActionPenUp

This action is issued when a pen transitions for the ‘down’ to the ‘up’ state. No openGL calls should be issued by the plug-in during this action.

Parameters:
Pre:

Post:

  • if the instance returns kOfxStatOK, the host should not pass the pen motion to any other interactive object it may own that shares the same view.

Returns:

  • kOfxStatOK, the action was trapped and the host should not pass the event to other objects it may own

  • kOfxStatReplyDefault , the action was not trapped and the host can deal with it if it wants

kOfxInteractActionKeyDown

This action is issued when a key on the keyboard is depressed. No openGL calls should be issued by the plug-in during this action.

Parameters:

  • handle – handle to an interact instance, cast to an OfxInteractHandle

  • inArgs – has the following properties on an image effect plugin

    • kOfxPropEffectInstance a handle to the effect for which the interact has been,

    • kOfxPropKeySym single integer value representing the key that was manipulated, this may not have a UTF8 representation (eg: a return key)

    • kOfxPropKeyString UTF8 string representing a character key that was pressed, some keys have no UTF8 encoding, in which case this is “”

    • kOfxPropTime the effect time at which changed occured

    • kOfxImageEffectPropRenderScale the render scale applied to any image fetched

  • outArgs – is redundant and is set to NULL

Pre:

Post:

  • if the instance returns kOfxStatOK, the host should not pass the pen motion to any other interactive object it may own that shares the same focus.

Returns:

  • kOfxStatOK , the action was trapped and the host should not pass the event to other objects it may own

  • kOfxStatReplyDefault , the action was not trapped and the host can deal with it if it wants

kOfxInteractActionKeyUp

This action is issued when a key on the keyboard is released. No openGL calls should be issued by the plug-in during this action.

Parameters:

  • handle – handle to an interact instance, cast to an OfxInteractHandle

  • inArgs – has the following properties on an image effect plugin

    • kOfxPropEffectInstance a handle to the effect for which the interact has been,

    • kOfxPropKeySym single integer value representing the key that was manipulated, this may not have a UTF8 representation (eg: a return key)

    • kOfxPropKeyString UTF8 string representing a character key that was pressed, some keys have no UTF8 encoding, in which case this is “”

    • kOfxPropTime the effect time at which changed occured

    • kOfxImageEffectPropRenderScale the render scale applied to any image fetched

  • outArgs – is redundant and is set to NULL

Pre:

Post:

  • if the instance returns kOfxStatOK, the host should not pass the pen motion to any other interactive object it may own that shares the same focus.

Returns:

  • kOfxStatOK , the action was trapped and the host should not pass the event to other objects it may own

  • kOfxStatReplyDefault , the action was not trapped and the host can deal with it if it wants

kOfxInteractActionKeyRepeat

This action is issued when a key on the keyboard is repeated. No openGL calls should be issued by the plug-in during this action.

Parameters:

  • handle – handle to an interact instance, cast to an OfxInteractHandle

  • inArgs – has the following properties on an image effect plugin

    • kOfxPropEffectInstance a handle to the effect for which the interact has been,

    • kOfxPropKeySym single integer value representing the key that was manipulated, this may not have a UTF8 representation (eg: a return key)

    • kOfxPropKeyString UTF8 string representing a character key that was pressed, some keys have no UTF8 encoding, in which case this is “”

    • kOfxPropTime the effect time at which changed occured

    • kOfxImageEffectPropRenderScale the render scale applied to any image fetched

  • outArgs – is redundant and is set to NULL

Pre:

Post:

  • if the instance returns kOfxStatOK, the host should not pass the pen motion to any other interactive object it may own that shares the same focus.

Returns:

  • kOfxStatOK , the action was trapped and the host should not pass the event to other objects it may own

  • kOfxStatReplyDefault , the action was not trapped and the host can deal with it if it wants

kOfxInteractActionGainFocus

This action is issued when an interact gains input focus. No openGL calls should be issued by the plug-in during this action.

Parameters:
Pre:

Returns:

kOfxInteractActionLoseFocus

This action is issued when an interact loses input focus. No openGL calls should be issued by the plug-in during this action.

Parameters:
Pre:

Returns:

Typedefs

typedef struct OfxInteract *OfxInteractHandle

Blind declaration of an OFX interactive gui.

typedef struct OfxInteractSuiteV1 OfxInteractSuiteV1

OFX suite that allows an effect to interact with an openGL window so as to provide custom interfaces.

struct OfxInteractSuiteV1
#include <ofxInteract.h>

OFX suite that allows an effect to interact with an openGL window so as to provide custom interfaces.

Public Members

OfxStatus (*interactSwapBuffers)(OfxInteractHandle interactInstance)

Requests an openGL buffer swap on the interact instance.

OfxStatus (*interactRedraw)(OfxInteractHandle interactInstance)

Requests a redraw of the interact instance.

OfxStatus (*interactGetPropertySet)(OfxInteractHandle interactInstance, OfxPropertySetHandle *property)

Gets the property set handle for this interact handle.