Roku Developer Program

[greubel]

How does this work ?

I was trying to do a fade to black by incrementing the alpha bits from 00 to FF but the transparency bounces all over the place.

clr = "#"+Hex(a)+Hex(b)+"000000"
ic.SetLayer(0, {Color:clr, CompositionMode:"Source_Over"})

[TheEndless]

What are your a and b values? I would think you should only have one Hex() call going from 0 to 255. Also, is Hex a valid BrightScript function, or did you write your own? I don't see it in the documentation.

[greubel]

a and b is the first and second digit of the x00 to xFF and Hex is my function that returns a string.
I displayed the resultant string and it was what is expected.

[TheEndless]

This works for me... Feel free to steal it. 😉

Function FadeToBlack( fadeStep = 1 As Integer ) As Object
	canvas = CreateObject( "roImageCanvas" )
	fade = {
		Color: "#00000000",
		TargetRect: { x: 0, y: 0, w: 1280, h: 720 }
	}
	canvas.SetLayer( 0, fade )
	canvas.Show()
	Sleep( 25 )
	For value = 0 To 255 Step fadeStep
		fade.Color = "#" + ByteToHex( value ) + "000000"
		canvas.SetLayer( 0, fade )
		Sleep( 25 )
	Next
	Return canvas
End Function

Function ByteToHex( byte As Integer ) As String
	If byte > 255 Then
		byte = 255
	End If
	hexValues = "0123456789ABCDEF"
	hex = hexValues.Mid( Int( byte / 16 ), 1 ) + hexValues.Mid( Mod( byte, 16 ), 1 )
	Return hex
End Function

' This function is not at all efficient, but the Roku's
' division is very sketchy at higher numbers
Function Mod( a as Integer, b as Integer ) as Integer
	If a = 0 Or b = 0 Or a = b Then
		Return 0
	ElseIf a < b Then
		Return a
	Else
		x = a - b
		While x >= b
			x = x - b
		End While
		Return x
	End If
End Function