.. currentModule:: Autograph

Edit Params
===========

Accessing params
----------------

Params are accessible on their parenting using :meth:`Autograph.Effect.param(uniqueName)` or :meth:`Autograph.Param.param(uniqueName)` functions.
Some commonly used params are directly declared as attributes on their parent object, with the attribute's name being the same as the :meth:`Autograph.Param.getUniqueName()`

For example, to access the ``mask`` of a :class:`Layer2D<Autograph.Layer2D>`:

.. code-block::

	print(layer.mask.getDisplayName())


Some parameters however are not available as class attributes because they are less frequently used. You can find out the unique-name of a :class:`Param<Autograph.Param>` in 2 ways:

In the UI, hover the mouse on the param to reveal its tooltip indicating the *Python script-name*

.. figure:: img/paramTooltip.jpeg
    :width: 300
    :align: center


From the Python Panel console in the UI, you can loop over all params in an :class:`Effect<Autograph.Effect>` ,e.g:


 .. code-block::

 	layer=Autograph.Layer2D()
 	for p in layer.getParams():
 		print(p.getUniqueName())



Setting a Param value
----------------------


Most parameters in the UI inherit :class:`DoubleParamBase<Autograph.DoubleParamBase>`, :class:`DoubleParam2DBase<Autograph.DoubleParam2DBase>`, :class:`DoubleParam3DBase<Autograph.DoubleParam3DBase>`, :class:`DoubleParam4DBase<Autograph.DoubleParam4DBase>`, :class:`BoolParamBase<Autograph.BoolParamBase>` or :class:`StringParamBase<Autograph.StringParamBase>`.

Each of these class internally store a value that can be set/get with :meth:`Autograph.DoubleParamBase.setValue` :meth:`Autograph.DoubleParamBase.getValue`. The same method can also be used to set keyframes.

For a more in-depth manipulation of the keyframes, the animation :class:`Curve<Autograph.Curve>` can be accessed with :meth:`Autograph.DoubleParamBase.getCurve`. 

.. note::

	When calling :meth:`Autograph.DoubleParamBase.getValue`, the returned value will properly apply all generator and modifiers. If you wish to get the internal animation curve value without applying generator/modifiers, directly use :meth:`Autograph.Curve.getValueAtTime`


Setting a Param generator
--------------------------


A :class:`Param<Autograph.Param` generator can be set or unset with :meth:`Autograph.Param.setGeneratorEffect` and takes in input an :class:`Effect<Autograph.Effect>` object.

There are 2 use-cases to set a generator:

1) Set the generator to point to a :class:`ProjectItem<Autograph.ProjectItem>`

.. code-block::

	project=Autograph.app.getActiveProject()
	myFootage=project.importFootage('/media/myfiles/video.mov')

	layer.source.setGeneratorEffect(myFootage)

	# which is similar to 
	layer.source.setGeneratorEffect(myFootage.createEffectSharedInstance())	


2) Create a new procedural generator

.. code-block::

	circle=Autograph.Effect('Autograph.CircleGenerator')
	layer.source.setGeneratorEffect(circle)


Adding modifiers
----------------

Modifiers are simply added on the :class:`ModifierList` returned by :meth:`Param.getModifiersList`.

.. code-block::

	blur=Autograph.Effect('Autograph.BlurModifier')
	layer.source.getModifiersList().addModifier(blur)


.. note::

	The list of available generators/modifiers `classID` can be queried by :meth:`Application.getGeneratorsClassID` and :meth:`Application.getModifiersClassID`.