This class represents a base for generic transformations of 2D points between different coordinate systems (including scaling and rotation). The transformations map objects between one coordinate system and another where it is assumed that a nested hierarchy of transformations can be defined.

It is assumed that transformations deal with Integer points. All transformations should return Integer coordinates (even though float points may be passed in as argument).

Compositions of transformations MUST work in the following order. A 'global' transformation (the argument in #composedWithGlobal:) is defined as a transformation that takes place between the receiver (the 'local') transformation and any 'global' point computations, whereas a 'local' transformation (e.g., the argument in #composedWithLocal:) takes place between the receiver ('global') and any 'local' points. For the transformation methods this means that combining a global and a local transformation will result in the following order:

globalPointToLocal: globalPoint
"globalPoint -> globalTransform -> localTransform -> locaPoint"
^localTransform globalPointToLocal:
(globalTransform globalPointToLocal: globalPoint)

localPointToGlobal: localPoint
"localPoint -> localTransform -> globalTransform -> globalPoint"
^globalTransform localPointToGlobal:
(localTransform localPointToGlobal: localPoint)

	composing
	composedWithGlobal: composedWithLocal:

	converting
	asCompositeTransform asMatrixTransform2x3

	encoding
	encodeForRemoteCanvas

	initialize
	setIdentity

	testing
	isCompositeTransform isIdentity isMatrixTransform2x3 isMorphicTransform isPureTranslation

	transforming points
	globalPointToLocal: globalPointsToLocal: invertBoundsRect: localPointToGlobal: localPointsToGlobal:

	transforming rects
	globalBoundsToLocal: localBoundsToGlobal: sourceQuadFor:

	accessing	top
	inverseTransformation Return the inverse transformation of the receiver

	composing	top
	composedWithGlobal: Return the composition of the receiver and the global transformation passed in. A 'global' transformation is defined as a transformation that takes place between the receiver (the 'local') transformation and any 'global' point computations, e.g., for the methods globalPointToLocal: globalPoint globalPoint -> globalTransform -> localTransform -> locaPoint localPointToGlobal: localPoint localPoint -> localTransform -> globalTransform -> globalPoint
	composedWithLocal: Return the composition of the receiver and the local transformation passed in. A 'local' transformation is defined as a transformation that takes place between the receiver (the 'global') transformation and any 'local' point computations, e.g., for the methods globalPointToLocal: globalPoint globalPoint -> globalTransform -> localTransform -> locaPoint localPointToGlobal: localPoint localPoint -> localTransform -> globalTransform -> globalPoint

	converting	top
	asCompositeTransform Represent the receiver as a composite transformation
	asMatrixTransform2x3 Represent the receiver as a 2x3 matrix transformation

	encoding	top
	encodeForRemoteCanvas encode this transform into a string for use by a RemoteCanvas

	initialize	top
	setIdentity Initialize the receiver to the identity transformation (e.g., not affecting points)

	testing	top
	isCompositeTransform Return true if the receiver is a composite transformation. Composite transformations may have impact on the accuracy.
	isIdentity Return true if the receiver is the identity transform; that is, if applying to a point returns the point itself.
	isMatrixTransform2x3 Return true if the receiver is 2x3 matrix transformation
	isMorphicTransform Return true if the receiver is a MorphicTransform, that is specifies the transformation values explicitly.
	isPureTranslation Return true if the receiver specifies no rotation or scaling.

	transforming points	top
	globalPointToLocal: Transform aPoint from global coordinates into local coordinates
	globalPointsToLocal: Transform all the points of inArray from global into local coordinates
	invertBoundsRect: Return a rectangle whose coordinates have been transformed from local back to global coordinates.
	localPointToGlobal: Transform aPoint from local coordinates into global coordinates
	localPointsToGlobal: Transform all the points of inArray from local into global coordinates

	transforming rects	top
	globalBoundsToLocal: Transform aRectangle from global coordinates into local coordinates
	localBoundsToGlobal: Transform aRectangle from local coordinates into global coordinates
	sourceQuadFor:

	instance creation	top
	fromRemoteCanvasEncoding: decode a transform from the given encoded string
	identity