TSelectionTracker

Croquet-Teapot

Comment: 

I am an example for simple selection tracking.

Hierarchy:

ProtoObject
Object
TObject
TFrame
TSelectionTracker

Summary:

instance variables:

frame normal position

methods:

instance class
render no messages

Detail:

instance variables:

frame
normal
position

instance methods:

render
renderFrame: ogl parent: parent root: root 

	| sel tfm axis angle select dir tri acPointer |
	acPointer _ ogl camera pointer.
	acPointer ifNil:[^self].
	select := acPointer doSelect.
	sel := acPointer lastSelection.
	frame := sel frame ifNil:[^0].
	position := sel point ifNil:[^0].
	normal := sel normal.
	normal ifNil:[
		tri := sel triangle ifNil:[^0].
		normal := ((tri at: 2) - (tri at: 1)) cross: ((tri at: 3) - (tri at: 2)).
		normal safelyNormalize.
	].
	tfm := frame globalTransform.
	position := tfm localPointToGlobal: position.
	normal := tfm localDirToGlobal: normal.

	normal safelyNormalize.
	dir := 0@0@1.
	angle := (normal dot: dir).
	(angle = 1.0 or:[angle = -1.0]) ifTrue:[
		axis := 0@1@0.
	] ifFalse:[
		axis := normal cross: dir.
		axis safelyNormalize.
	].
	angle := angle arcCos radiansToDegrees negated.
	self orientation: (B3DRotation axis: axis angle: angle) asMatrix4x4.
	self translation: position.
	"Do not pick while rendering the tracker"
	^[acPointer doSelect: false.
	super renderFrame: ogl parent: parent root: root] ensure:[
		acPointer doSelect: select.
	].
renderFrame: ogl space: sp 

	| sel tfm axis angle select dir tri acPointer |
	acPointer _ ogl camera pointer.
	acPointer ifNil:[^self].
	select := acPointer doSelect.
	sel := acPointer lastSelection.
	frame := sel frame ifNil:[^0].
	position := sel point ifNil:[^0].
	normal := sel normal.
	normal ifNil:[
		tri := sel triangle ifNil:[^0].
		normal := ((tri at: 2) - (tri at: 1)) cross: ((tri at: 3) - (tri at: 2)).
		normal safelyNormalize.
	].
	tfm := frame globalTransform.
	position := tfm localPointToGlobal: position.
	normal := tfm localDirToGlobal: normal.

	normal safelyNormalize.
	dir := 0@0@1.
	angle := (normal dot: dir).
	(angle = 1.0 or:[angle = -1.0]) ifTrue:[
		axis := 0@1@0.
	] ifFalse:[
		axis := normal cross: dir.
		axis safelyNormalize.
	].
	angle := angle arcCos radiansToDegrees negated.
	self orientation: (B3DRotation axis: axis angle: angle) asMatrix4x4.
	self translation: position.
	"Do not pick while rendering the tracker"
	^[acPointer doSelect: false.
	super renderFrame: ogl space: sp] ensure:[
		acPointer doSelect: select.
	].

class methods:

^top

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