com.degrafa.geometry.AdvancedQuadraticBezier

Public Properties

	Property		Defined by
		alpha : Number The alpha setting that applies to this object.	Geometry
		autoClearGraphicsTarget : Boolean When using a graphicsTarget and if this property is set to true the draw phase will clear the graphics context before drawing.	Geometry
		bottom : Number When set, the bottom of the layout will be located offset from the bottom of it's parent.	Geometry
		bounds : Rectangle The tight bounds of this element as represented by a Rectangle.	Geometry
		clippingRectangle : Rectangle A clipping rectangle to use when rendering this geometry.	Geometry
		close : Boolean If true draws a line from the end point to the start point to close this curve.	QuadraticBezier
		commandStack : CommandStack Provides access to the command stack.	Geometry
		currentState : String The current view state.	Geometry
		cx : Number The x-coordinate of the control point of the curve.	QuadraticBezier
		cy : Number The y-coordinate of the control point of the curve.	QuadraticBezier
		data : Object QuadraticBezier short hand data value.	QuadraticBezier
		decoratorCollection : DecoratorCollection Access to the Decorator collection object for this Geometry object.	Geometry
		decorators : Array A array of IDecorator objects to be applied on this Geometry.	Geometry
		derive : QuadraticBezier An object to derive this objects properties from.	QuadraticBezier
		document : Object The MXML document that created this object.	DegrafaObject
		enableEvents : Boolean Enable events for this object.	DegrafaObject
		fill : IGraphicsFill Defines the fill object that will be used for rendering this geometry object.	Geometry
		filters : Array An array of BitmapFilter objects applied to this Geometry.	Geometry
		geometricLength : Number Returns geometric length of this object.	Geometry
		geometry : Array A array of IGeometryComposition objects.	Geometry
		geometryCollection : GeometryCollection Access to the Degrafa geometry collection object for this geometry object.	Geometry
		graphicsTarget : Array One or more display object's that this Geometry is to be drawn to.	Geometry
		graphicsTargetCollection : DisplayObjectCollection Access to the Degrafa target collection object for this geometry object.	Geometry
		hasDecorators : Boolean Returns true if this Geometry has decorators.	Geometry
		hasEventManager : Boolean Tests to see if a EventDispatcher instance has been created for this object.	DegrafaObject
		hasFilters : Boolean Returns true if this Geometry has filters.	Geometry
		hasLayout : Boolean Returns true if this Geometry has layout.	Geometry
		hasStates : Boolean Returns true if this Geometry has states.	Geometry
		hasTriggers : Boolean Returns true if this Geometry has triggers.	Geometry
		height : Number Defines the height of the layout boundary.	Geometry
		horizontalCenter : Number When set, if left or right is not set, the layout will be centered horizontally offset by the numeric value of this property.	Geometry
		id : String The identifier used by document to refer to this object.	DegrafaObject
		IGraphicParent : IGraphic	Geometry
		inheritFill : Boolean If set to true and no fill is defined and there is a parent object then this object will walk up through the parents to retrive a fill object.	Geometry
		inheritStroke : Boolean If set to true and no stroke is defined and there is a parent object then this object will walk up through the parents to retrive a stroke object.	Geometry
		invalidated : Boolean Specifies whether this object is to be re calculated on the next cycle.	Geometry
		isInitialized : Boolean	DegrafaObject
		isInvalidated : Boolean Returns true if this Geometry object is invalidated	Geometry
		isRootGeometry : Boolean Returns true if this Geometry object is a root Geometry Object.	Geometry
		layoutConstraint : LayoutConstraint The layout constraint that is used for positioning/sizing this geometry object.	Geometry
		_layoutMatrix : Matrix Access to the layout matrix if this Geometry has layout.	Geometry
		layoutRectangle : Rectangle Returns the constraint based layout rectangle for this object or bounds if no layout constraint is specified.	Geometry
		left : Number When set, the left of the layout will be located offset by the value of this property multiplied by the containing width.	Geometry
		maintainAspectRatio : Boolean When true, the size of the layout will always maintain an aspect ratio relative to the ratio of the current width and height properties, even if those properties are not in control of the height and width of the layout.	Geometry
		mask : IGeometryComposition A separate geometry object to use as a mask when rendering this geometry.	Geometry
		maskMode : String The mode used when this object is being masked by the geometry assigned to the mask property.	Geometry
		maskSpace : String The coordinate space within which the referenced mask geometry is rendered before being applied as a mask (respecting maskMode) to this object.	Geometry
		maxHeight : Number The maximum height that can be applied to the layout.	Geometry
		maxWidth : Number The maximum width that can be applied to the layout.	Geometry
		maxX : Number The maximum x location that can be applied to the layout.	Geometry
		maxY : Number The maximum y location that can be applied to the layout.	Geometry
		minHeight : Number The minimum height that can be applied to the layout.	Geometry
		minWidth : Number The minimum width that can be applied to the layout.	Geometry
		minX : Number The minimum x location that can be applied to the layout.	Geometry
		minY : Number The minimum y location that can be applied to the layout.	Geometry
		name : String The name that refers to this object.	DegrafaObject
		objectBindings : Array	DegrafaObject
		parent : IDegrafaObject The current degrafa object parent.	DegrafaObject
		percentHeight : Number When set, the height of the layout will be set as the value of this property multiplied by the containing height.	Geometry
		percentWidth : Number When set, the width of the layout will be set as the value of this property multiplied by the containing width.	Geometry
		right : Number When set, the right of the layout will be located offset by the value of this property multiplied by the containing width.	Geometry
		scaleOnLayout : Boolean When using layout this flag will determine if you want Scale to be applied to fit layout rules	Geometry
		state : String The state at which to draw this object.	Geometry
		stateEvent : String The state event at which to draw this object.	Geometry
		states : Array An array of states defined for this Geometry.	Geometry
		stroke : IGraphicsStroke Defines the stroke object that will be used for rendering this geometry object.	Geometry
		styleName : Object The css style name associated with this Geometry.	Geometry
		suppressEventProcessing : Boolean Temporarily suppress event processing for this object.	DegrafaObject
		targetCoordinateSpace : DisplayObject The display object that defines the coordinate system to use.	Geometry
		top : Number When set, the top of the layout will be located offset from the top of it's parent.	Geometry
		transform : ITransform Defines the transform object that will be used for rendering this geometry object.	Geometry
		transformBounds : Rectangle Returns a transformed version of this objects bounds as represented by a Rectangle.	Geometry
		transformContext : Matrix A reference to the transformation matrix context within which local transforms will be applied.	Geometry
		triggers : Array An array of ITrigger objects that this Geometry object will use.	Geometry
		verticalCenter : Number When set, if top or bottom is not set, the layout will be centered vertically offset by the numeric value of this property.	Geometry
		visible : Boolean Controls the visibility of this geometry object.	Geometry
		width : Number Defines the width of the layout.	Geometry
		x : Number Defines the x location (top left) of the layout.	Geometry
		x0 : Number The x0-coordinate of the start point of the curve.	QuadraticBezier
		x1 : Number The x-coordinate of the end point of the curve.	QuadraticBezier
		y : Number Defines the y location (top left) of the layout.	Geometry
		y0 : Number The y0-coordinate of the start point of the curve.	QuadraticBezier
		y1 : Number The y-coordinate of the end point of the curve.	QuadraticBezier

	Property	Defined by
		eventDispatcher : EventDispatcher EventDispatcher instance for this object.	DegrafaObject
		_fill : IGraphicsFill	Geometry
		_stroke : IGraphicsStroke	Geometry

Public Methods

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Show Inherited Public Methods

	Method		Defined by
		AdvancedQuadraticBezier(x0:Number, y0:Number, cx:Number, cy:Number, x1:Number, y1:Number) Constructor.	AdvancedQuadraticBezier
		addEventListener(type:String, listener:Function, useCapture:Boolean = false, priority:int = 0, useWeakReference:Boolean = true):void Registers an event listener object with an EventDispatcher object so that the listener receives notification of an event.	DegrafaObject
		angleAt(t:Number):Number Returns the angle of a point t(0-1) on the path.	Geometry
		calculateLayout(childBounds:Rectangle = null):void Performs the specific layout work required by this Geometry.	QuadraticBezier
		clearGraphicsTargets():void Clears all graphics targets specified in the graphicsTarget array.	Geometry
		dispatchEvent(evt:Event):Boolean Dispatches an event into the event flow.	DegrafaObject
		dispatchPropertyChange(bubbles:Boolean = false, property:Object = null, oldValue:Object = null, newValue:Object = null, source:Object = null):Boolean Dispatches an property change event into the event flow.	DegrafaObject
		draw(graphics:Graphics, rc:Rectangle):void Begins the draw phase for geometry objects.	QuadraticBezier
		drawToTargets():void Requests a draw for each graphics target specified in the graphicsTarget array.	Geometry
		endDraw(graphics:Graphics):void Ends the draw phase for geometry objects.	Geometry
		hasEventListener(type:String):Boolean Checks whether the EventDispatcher object has any listeners registered for a specific type of event.	DegrafaObject
		initChange(property:String, oldValue:Object, newValue:Object, source:Object):void Helper function for dispatching property changes	DegrafaObject
		initFill(graphics:Graphics, rc:Rectangle):void Initialise the fill for this geometry object.	Geometry
		initialized(document:Object, id:String):void Called after the implementing object has been created and all component properties specified on the MXML tag have been initialized.	DegrafaObject
		initStroke(graphics:Graphics, rc:Rectangle):void Initialise the stroke for this geometry object.	Geometry
		interpolate(points:Array):Number interpolate Compute control points so that quadratic Bezier passes through three points at the specified parameter value.	AdvancedQuadraticBezier
		join(_x:Number, _y:Number, _tension:Number = 1):AdvancedQuadraticBezier join Given the current `AdvancedQuadraticBezier` and an arbitrary point, return a new `AdvancedQuadraticBezier` instance so that the new quadratic Bezier interpolates the input point and matches tangent with the current quadratic Bezier at its origin.	AdvancedQuadraticBezier
		pointAt(t:Number):Point Returns the point at t(0-1) on this object.	Geometry
		preDraw():void Performs any pre calculation that is required to successfully render this element.	AdvancedQuadraticBezier
		removeEventListener(type:String, listener:Function, useCapture:Boolean = false):void Removes a listener from the EventDispatcher object.	DegrafaObject
		styleChanged(styleProp:String):void Called when the value of a style property is changed.	Geometry
		tAtMaxX():Number tAtMaxX Find t-parameter at which the x-coordinate is a maximum.	AdvancedQuadraticBezier
		tAtMaxY():Number tAtMaxY Find t-parameter at which the y-coordinate is a maximum.	AdvancedQuadraticBezier
		tAtMinX():Number tAtMinX Find t-parameter at which the x-coordinate is a minimum.	AdvancedQuadraticBezier
		tAtMinY():Number tAtMinY Find t-parameter at which the y-coordinate is a minimum.	AdvancedQuadraticBezier
		willTrigger(type:String):Boolean Checks whether an event listener is registered with this EventDispatcher object or any of its ancestors for the specified event type.	DegrafaObject
		xAtY(_y:Number):Array xAtY Return the set of x-coordinates corresponding to the input y-coordinate.	AdvancedQuadraticBezier
		yAtX(_x:Number):Array yAtX Return the set of y-coordinates corresponding to the input x-coordinate.	AdvancedQuadraticBezier

	Method	Defined by
		propertyChangeHandler(event:PropertyChangeEvent):void Principle event handler for any property changes to a geometry object or it's child objects.	Geometry

Constructor detail

AdvancedQuadraticBezier

()

constructor

public function AdvancedQuadraticBezier(x0:Number, y0:Number, cx:Number, cy:Number, x1:Number, y1:Number)

Constructor.

The advanced quadratic Bézier constructor accepts 6 optional arguments that define it's start, end and controls points.

Parameters

	`x0:Number` — A number indicating the starting x-axis coordinate.

	`y0:Number` — A number indicating the starting y-axis coordinate.

	`cx:Number` — A number indicating the control x-axis coordinate.

	`cy:Number` — A number indicating the control y-axis coordinate.

	`x1:Number` — A number indicating the ending x-axis coordinate.

	`y1:Number` — A number indicating the ending y-axis coordinate.

Method detail

interpolate

()

method

public function interpolate(points:Array):Number

interpolate

Compute control points so that quadratic Bezier passes through three points at the specified parameter value. Parameters

points:Array — - array of three Point references, representing the coordinates of the interpolation points.

Returns

Number — Number the parameter value in [0,1] at which the Bezier curve passes through the second control point (determined by a chord-length parameterization). A negative value is returned if less than three interpolation points are provided.

join

()

method

public function join(_x:Number, _y:Number, _tension:Number = 1):AdvancedQuadraticBezier

join

Given the current AdvancedQuadraticBezier and an arbitrary point, return a new AdvancedQuadraticBezier instance so that the new quadratic Bezier interpolates the input point and matches tangent with the current quadratic Bezier at its origin. In other words, given the current (x0,y0), (cx,cy), and (x1,y1), return a new AdvancedQuadraticBezier with parameters (w0,u0), (zx,zy), and (w1,u1) so that w0 = x1, u0 = y1, and the segment from (cx,cy) to (x1,y1) and (w0,u0) to (zx,zy) have the same slope. This is one prelude to a more general quadratic spline.

Parameters

	`_x:Number` — x-coordinate of final interpolation point of output quadratic Bezier.

	`_y:Number` — y-coordinate of final interpolation point of output quadratic Bezier.

	`_tension:Number` (default = `1`) — - tension parameter between 0 and 1. 0 produces a near linear curve while 1 produces a curve whose control point is the projection of (_x,_y), onto the vector from (cx,cy) to (x1,y1), unless that point is less than one third the distance from (cx,cy) to (x1,y1). This may be broken into two parameters in the future for more control. Values outside the interval [0,1] are clipped to either 0 or 1.

Returns

AdvancedQuadraticBezier — AdvancedQuadraticBezier reference to quadratic Bezier that can be considered an 'add on' curve to the current quadratic bezier with matching tangents at the join (x1,y1).

preDraw

()

method

public override function preDraw():void

Performs any pre calculation that is required to successfully render this element. Including bounds calculations and lower level drawing command storage. Each geometry object overrides this and is responsible for it's own pre calculation cycle.

tAtMaxX

()

method

public function tAtMaxX():Number

tAtMaxX

Find t-parameter at which the x-coordinate is a maximum.

Returns

Number — Number Parameter value in [0,1] at which the quadratic Bezier curve's x-coordinate is a maximum.

tAtMaxY

()

method

public function tAtMaxY():Number

tAtMaxY

Find t-parameter at which the y-coordinate is a maximum.

Returns

Number — Number Parameter value in [0,1] at which the quadratic Bezier curve's y-coordinate is a maximum.

tAtMinX

()

method

public function tAtMinX():Number

tAtMinX

Find t-parameter at which the x-coordinate is a minimum.

Returns

Number — Number Parameter value in [0,1] at which the qudratic Bezier curve's x-coordinate is a minimum

tAtMinY

()

method

public function tAtMinY():Number

tAtMinY

Find t-parameter at which the y-coordinate is a minimum.

Returns

Number — Number - Parameter value in [0,1] at which the quadratic Bezier curve's y-coordinate is a minimum.

xAtY

()

method

public function xAtY(_y:Number):Array

xAtY

Return the set of x-coordinates corresponding to the input y-coordinate.

Parameters

_y:Number — y-coordinate at which the desired x-coordinates are desired

Returns

Array — Array set of (t,x)-coordinates at the input y-coordinate provided that the y-coordinate is inside the range covered by the quadratic Bezier in [0,1]; that is there must exist t in [0,1] such that By(t) = _y. If the input y-coordinate is not inside the range covered by the Bezier curve, the returned array is empty. Otherwise, the array contains either one or two x-coordinates. There are issues with curves that are exactly or nearly (for numerical purposes) horizontal in which there could theoretically be an infinite number of x-coordinates for a single y-coordinate. This method does not work in such cases, although compensation might be added in the future.

Each array element is a reference to an Object whose 't' parameter represents the Bezier t parameter. The Object 'x' property is the corresponding x-coordinate. The returned (t,x) coordinates may be used by the caller to determine which of two returned x-coordinates might be preferred over the other.

yAtX

()

method

public function yAtX(_x:Number):Array

yAtX

Return the set of y-coordinates corresponding to the input x-coordinate.

Parameters

_x:Number — x-coordinate at which the desired y-coordinates are desired

Returns

Array — Array set of (t,y)-coordinates at the input x-coordinate provided that the x-coordinate is inside the range covered by the quadratic Bezier in [0,1]; that is there must exist t in [0,1] such that Bx(t) = _x. If the input x-coordinate is not inside the range covered by the Bezier curve, the returned array is empty. Otherwise, the array contains either one or two y-coordinates. There are issues with curves that are exactly or nearly (for numerical purposes) vertical in which there could theoretically be an infinite number of y-coordinates for a single x-coordinate. This method does not work in such cases, although compensation might be added in the future.

Each array element is a reference to an Object whose 't' parameter represents the Bezier t parameter. The Object 'y' property is the corresponding y-value. The returned (t,y) coordinates may be used by the caller to determine which of two returned y-coordinates might be preferred over the other.

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Class AdvancedQuadraticBezier	Properties \| Methods \| Events

Package	com.degrafa.geometry
Class	public class AdvancedQuadraticBezier
Inheritance	AdvancedQuadraticBezier QuadraticBezier Geometry DegrafaObject