// 
// The shortest program to draw a sierpinski triangle
//
Program Sierpinski
	
	Define test As BitFiddle  // test addition to surface library, "And_"...


	Method Main()

		SetScreenSize( 320, 320 )
		
		Define x As Integer
		Define y As Integer
		
		// Seven lines for the action
		For y = 0 To 255
			For x = 0 To y
				If test.And_( x, y - x ) = 0 Then
					PutPixel( x + 158 - .5*y, y + 30 )
				End If
			Next
		Next

	End Method

	// This Function is only needed for Phrogram.
	// Phrogram only handles And operations for Booleans
	// In this program we have to operate two Integers bit by bit (&)
	Function AndInteger( a As Integer, b As Integer ) As Integer
		Define a1	As Integer
		Define b1	As Integer
		Define c	As Integer = 0
		Define d	As Integer = 1
		While Not ( a = 0 Or b = 0 )
			a1 = a
			a  = a / 2
			b1 = b
			b  = b / 2
			If a1 <> 2 * a Then
				If b1 <> 2 * b Then
					c = c + d
				End If
			End If
			d = d * 2
		End While
		Return c
	End Function
	
End Program