Stacker

function init()
    setName("Stacker")
    setDesc("Stacks 2 images using black as transparency")
    setSize(80,8+24+64)
    addOutput(24+32)
    addInput("",24+32-24)
    addInput("",24+32+24)
end
-- Ugly way to use channels
function apply()
    math.randomseed (getValue(5,0,0,1))
    x = 0
    y = 0
    tileSize = getTileSize()
    for i=0, tileSize*tileSize-1 do
        x = i%tileSize
        y = math.floor(i/tileSize)
        outr, outg, outb = getValue(1,x,y,1)
        a = outr + outg + outb
        --if a > 0 then
            setPixel(0,x,y,outr,outg,outb)
        --end

        outr, outg, outb = getValue(0,x,y,1)
        b = outr + outg + outb
        if b > 0 then
            setPixel(0,x,y,outr,outg,outb)
        end
    end
end