GWBasic/QBasic Canonball

100 REM === BASIC Month 3: Cannonball
110 REM === http://reddit.com/r/RetroBattlestations
120 REM === written by FozzTexx
130 REM === GWBasic/QBasic version tweaked by EkriirkE

200 REM === Clear screen and setup variables
210 CLS
220 CL = 80: RW = 24: REM Columns and Rows of screen
230 CA = 45: CN = 5: REM Angle and length of cannon
240 CX = 5: PX = CL - 5: SC = 0: LV = 3
250 PI = 3.14159

300 REM === Play game
310 CV = INT(RND(1) * 15) + 10: GOSUB 4010: GOSUB 2010
320 GOSUB 2510
330 IF KE$ = "w" OR KE$ = "K" THEN CA = CA + 5: IF CA > 85 THEN CA = 85
340 IF KE$ = "s" OR KE$ = "M" THEN CA = CA - 5: IF CA < 15 THEN CA = 15
350 IF KE$ = "q" OR KE$ = CHR$(27) THEN END
360 IF KE$ = " " THEN 410
370 GOSUB 1010
380 GOTO 320

400 REM === Fire!
410 LX = (CN + 1) * COS((360 - CA) * PI / 180): LY = (CN + 1) * SIN((360 - CA) * PI / 180)
420 BX = CX + LX: BY = RW + LY
430 GOSUB 1510
440 VX = CV * COS((360 - CA) * PI / 180): VY = CV * SIN((360 - CA) * PI / 180)

500 REM === Move player and animate ball
510 GOSUB 2510
511 t = TIMER: WHILE TIMER - t < .2: WEND: REM =E= DELAY FOR BEING TOO FAST!
520 IF KE$ = "a" OR KE$ = "K" THEN PX = PX - 1: IF PX < CX + CN THEN PX = CX + CN
530 IF KE$ = "d" OR KE$ = "M" THEN PX = PX + 1: IF PX > CL - 1 THEN PX = CL - 1
540 GOSUB 2010
550 BX = BX + (VX / 10): BY = BY + (VY / 10): GOSUB 1510
560 VY = VY + 2
570 IF BY < RW THEN 510
580 P$ = " ": X1% = BX%: Y1% = BY%: GOSUB 3510

600 REM === Score or die
610 LX = BX - BX%: LY = BY - BY%: L2 = RW - BY%
620 IX = BX% + LX * (L2 / LY)
630 IF IX >= PX - 1 AND IX <= PX + 1 THEN SC = SC + 10: GOTO 310
640 LV = LV - 1: GOSUB 4010
650 IF LV < 1 THEN P$ = "GAME OVER": X1% = (CL - LEN(P$)) / 2: Y1% = RW / 2: GOSUB 3510: END
660 GOTO 310

1000 REM === Draw cannon
1010 IF (CA = LA) THEN RETURN
1020 P$ = "ANGLE: " + STR$(CA) + " ": X1% = 2: Y1% = 1: GOSUB 3510
1030 LX = CN * COS((360 - LA) * PI / 180): LY = CN * SIN((360 - LA) * PI / 180)
1040 X1 = CX: Y1 = RW: X2 = X1 + LX: Y2 = Y1 + LY: P$ = " ": GOSUB 3010
1050 LX = CN * COS((360 - CA) * PI / 180): LY = CN * SIN((360 - CA) * PI / 180)
1060 X2 = X1 + LX: Y2 = Y1 + LY: P$ = "%": GOSUB 3010
1070 LA = CA: RETURN

1500 REM === Draw ball
1510 X1% = BX: Y1% = BY: P$ = "o": GOSUB 3510
1520 IF BX% <> X1% OR BY% <> Y1% THEN X1% = BX%: Y1% = BY%: P$ = " ": GOSUB 3510
1530 BX% = BX: BY% = BY
1540 RETURN

2000 REM === Draw player
2010 P$ = "U": X1% = PX: Y1% = RW: GOSUB 3510
2020 IF PX% <> X1% THEN X1% = PX%: P$ = " ": GOSUB 3510
2030 PX% = PX
2040 RETURN

2500 REM === Read the keyboard
2510 KE$ = RIGHT$(INKEY$, 1)
2520 RETURN

3000 REM === Plot a line
3010 X1% = X1: X2% = X2: Y1% = Y1: Y2% = Y2
3020 DX% = ABS(X2% - X1%): SX% = -1: IF X1% < X2% THEN SX% = 1
3030 DY% = ABS(Y2% - Y1%): SY% = -1: IF Y1% < Y2% THEN SY% = 1
3040 ER% = -DY%: IF DX% > DY% THEN ER% = DX%
3050 ER% = ER% / 2
3060 GOSUB 3510
3070 IF X1% = X2% AND Y1% = Y2% THEN RETURN
3080 E2% = ER%
3090 IF E2% > -DX% THEN ER% = ER% - DY%: X1% = X1% + SX%
3100 IF X1% = X2% AND Y1% = Y2% THEN RETURN
3110 IF E2% < DY% THEN ER% = ER% + DX%: Y1% = Y1% + SY%
3120 IF X1% = X2% AND Y1% = Y2% THEN RETURN
3130 GOTO 3060

3500 REM === Plot a point
3510 IF X1% < 1 OR X1% > CL OR Y1% < 1 OR Y1% > RW THEN RETURN
3520 LOCATE Y1%, X1%
3530 PRINT P$;
3540 RETURN

4000 REM === Show score/lives/velocity
4010 P$ = "VELOCITY: " + STR$(CV) + " ": X1% = CL / 3: Y1% = 1: GOSUB 3510
4020 P$ = "SCORE: " + STR$(SC): X1% = CL * 2 / 3: GOSUB 3510
4030 P$ = MID$("   UUU", LV + 1, 3): X1% = CL - 2: GOSUB 3510
4040 RETURN