Method draw

src/main/java/field/graphics/FBOStack.kt:22–29

    var write = depth - 1

    fun draw(): Boolean {
        val b = stack[write].draw()

        write = (write + 1) % depth
        read = (read + 1) % depth

        return b
    }

    fun getReadFBO(): FBO {
        return stack[read]