Mosaic Effect Code

_TITLE "Test Program"
screenOne& = _NEWIMAGE(800, 600, 32)
SCREEN screenOne&
imageOne& = _LOADIMAGE("effect.png")
blockSize = 1
WHILE 1
    CLS
    IF _KEYDOWN(19712) THEN
        blockSize = blockSize + 2
    END IF
    IF _KEYDOWN(19200) THEN
        blockSize = blockSize - 2
    END IF
    FOR x = 0 TO 799
        FOR y = 0 TO 599
            _PUTIMAGE (x * blockSize, y * blockSize)-((x * blockSize) + blockSize, (y * blockSize) + blockSize), imageOne&, 0, (x * blockSize, y * blockSize)-(x * blockSize, y * blockSize)
        NEXT
    NEXT
    _DISPLAY
    _LIMIT 60
WEND