'SETMUSIC 0 "O6L2BAGFEDC" PLAYMUSIC ' PLAYER SHOOT
	'SETMUSIC 0 "O4L2BAGFEDC" PLAYMUSIC ' INVADER SHOOT
	'SETMUSIC 0 "O4L3C<BAGFEDCDEFGAB>C<BAGFEDCDEFGAB>C" PLAYMUSIC	' BIG UFO
	'SETMUSIC 3 "O5L2BAGFEDCV4BAGFEDV2CBAGFEDC" PLAYMUSIC	' EXPLOSION
	SETCHAR 0 !00000101033F7F7F
	SETCHAR 1 !0000000080F8FCFC
	SETCHAR 2 !00423C5ABDA51800
	SETCHAR 3 !0024BD5A3C244200
	SETCHAR 4 !00817E99FF3C4200
	SETCHAR 5 !00247E99FF3C1800
	SETCHAR 6 !00183C5ADB7E2400
	SETCHAR 7 !00183C5ADB7EDB00
	SETCHAR 8 !00031F7F45FF3100
	SETCHAR 9 !00C0F8FE92FF8C00
	SETCHAR 10 !0925975F3FCF1200
	SETCHAR 11 !2048D2F4F8E69000
	SETCHAR 12 !1F3F7FFFFFFFFEFC
	SETCHAR 13 !F8FCFEFFFFFF7F3F
	SETCHAR 14 !013373FFFFFFFEFC
	SETCHAR 15 !B89CD8FFFFFF7F3F
	SETCHAR 16 !000042C2C7EFFEFC
	SETCHAR 17 !0080C0D9DFFF7F3F
	SETCHAR 18 !00000000008ADEFC
	SETCHAR 19 !00000080C0D27733
	SETCHAR 20 !FF00000000000000
	SETCHAR 21 !00000000000000FF
	
	BORDER INK_BLACK
	COLOR INK_WHITE + PAPER_BLACK
	CLS
	
	' PINTEM EL MARCADOR
	LOCATE 1 0 PRINT "0000"
	COLOR INK_GRAY + PAPER_BLACK
	LOCATE 0 1 PRINT !14141414141414141414141414141414
	LOCATE 0 11 PRINT !15151515151515151515151515151515
	COLOR INK_YELLOW + PAPER_BLACK
	LOCATE 13 0 PRINT !E0E0E0

	LET ITER = 0
	LET HEIGHT = 0
	LET ALIEN = 0
	LET AX = 8
	LET AY = 18
	DIM A(3)
	A(0) = &HFF
	A(1) = &HFF
	A(2) = &HFF
	LET POS = 0
	LET MASK = 1

	'PINTEM ELS MARSIANITOS
	FOR I = 0 TO 24
		IF I < 6 THEN SETSPRITE I 4 INK_MAGENTA END
		IF (I >= 6) AND (I < 12) THEN SETSPRITE I 2 INK_LIME END
		IF (I >= 12) AND (I < 18) THEN SETSPRITE I 2 INK_LIME END
		IF I >= 18 THEN SETSPRITE I 6 INK_CYAN END
		PUTSPRITE I AX AY
		AX = AX + 16
		IF AX = 104 THEN
			AX = 8
			AY = AY + 10
		END
	END
	
	' PINTEM AL JUGADOR
	LET X = 32
	SETSPRITE 24 0 INK_CYAN
	SETSPRITE 25 1 INK_CYAN
	PUTSPRITE 24 X 95
	PUTSPRITE 25 X+8 95
	
	' PINTEM LES BARRERES
	COLOR INK_RED + PAPER_BLACK
	LOCATE 1 10 PRINT !0C0D20200C0D20200C0D20200C0D20
	UPDATESCR

MAIN_GAME:
	' MOVEM AL JUGADOR
	IF KEYPRESSED BTN_RIGHT THEN
		INC X 
		IF X > 122 THEN X = 122 END
		GOSUB DRAW_PLAYER
	END
	IF KEYPRESSED BTN_LEFT THEN
		DEC X
		IF X < 7 THEN X = 7 END
		GOSUB DRAW_PLAYER
	END
	
	'MOVEM ALS MARSIANITOS
	LET AX = 8 + ITER
	LET AY = 18 + HEIGHT * 4
	LET POS = 0
	LET MASK = 1
	FOR I = 0 TO 24
		IF I = ALIEN THEN
			INC ALIEN
			IF ALIEN = 24 THEN
				ALIEN = 0
				IF (HEIGHT MOD 2) = 0 THEN INC ITER ELSE DEC ITER END
				IF (ITER = 40) OR (ITER = 0) THEN INC HEIGHT END
			END
			IF (A(POS) AND MASK) = MASK THEN
				PUTSPRITE I AX AY
				GOTO ALIEN_FOUND
			END
		END
		MASK = MASK * 2
		IF MASK = 0 THEN
			MASK = 1
			INC POS
			IF POS = 3 THEN POS = 0 END
		END
		AX = AX + 16
		IF AX = 104 + ITER THEN
			AX = 8 + ITER
			AY = AY + 10
		END
	END
ALIEN_FOUND:
	UPDATESCR
	GOTO MAIN_GAME
DRAW_PLAYER:
	PUTSPRITE 24 X 95
	PUTSPRITE 25 X+8 95
	RETURN
LOOP: GOTO LOOP