Class Gradient

public class Gradient : CanvasIdentifiedObject 

Gradients have two flavors:

1. Linear
2. Radial

Usage:

There are several steps required to use a gradient:

1. Create the Gradient object
2. Add two or more ColorStops
3. Setup the Gradient object
4. Use the Gradient to initialize a StrokeStyle or FillStyle
5. Because the Gradient is a CanvasIdentifiedObject, be sure it isReady prior to rendering
6. Render the associated FillStyle prior to the object(s) to be filled with the gradient

Example:

var gradient : Gradient

init() {
    gradient = Gradient(mode:.linear(start:Point(x:0, y:60), end:Point(x:320, y:60)))
    gradient.addColorStop(ColorStop(position:0.0, color:Color(.red)))
	gradient.addColorStop(ColorStop(position:0.25, color:Color(.yellow)))
    gradient.addColorStop(ColorStop(position:0.5, color:Color(.green)))
    gradient.addColorStop(ColorStop(position:0.5, color:Color(.green)))
    gradient.addColorStop(ColorStop(position:0.5, color:Color(.green)))
}

override func setup(canvas:Canvas) {
    canvas.setup(gradient) 
}

override func render(canvas:Canvas) {
    if gradient.isReady {
	    let fillStyle = FillStyle(gradient:gradient)
	    canvas.render(fillStyle, rectangle)
	}
}

public init(mode:Mode) 

public let mode : Mode

public private(set) var colorStops : [ColorStop]

public func addColorStop(_ colorStop:ColorStop)