EXPOSURE VALUE CALCULATOR PRO

REM IT WORKS ONLY UNDER RFO BASIC! FOR ANDROID

FN.DEF log2 (valore)
result = LOG(valore) / LOG(2)
FN.rtn result
FN.END

FN.DEF calculate(ev1, av2)
pt = pow(av2,2)
ev2 = log2(pt)
rst = ev1- ev2
IF rst < 0
rst = ABS(rst)
endif
result = pow(2,rst)
FN.rtn result
FN.END

FN.DEF check(strnumber$)
c = 0
FOR i = 1 TO LEN(strnumber$)
car$ = MID$(strnumber$, i, 1)
IF car$ = "0"
c = c + 1
endif
IF car$ = "1"
c = c + 1
endif
IF car$ = "2"
c = c + 1
endif
IF car$ = "3"
c = c + 1
endif
IF car$ = "4"
c = c + 1
endif
IF car$ = "5"
c = c + 1
endif
IF car$ = "6"
c = c + 1
endif
IF car$ = "7"
c = c + 1
endif
IF car$ = "8"
c = c + 1
endif
IF car$ = "9"
c = c + 1
endif
IF car$ = "."
c = c + 1
endif
NEXT
IF c = LEN(strnumber$)
FN.rtn 1
endif
IF c <> LEN(strnumber$)
FN.rtn 0
endif
FN.END

start:
array.load diaframmi[],1,1.2,1.4,1.7,1.8,2,2.4,2.8,3.3,3.4,4,4.8,5.6,6.7,8,9.5,11,13.0,16,19,22
inizio:
CLS
switch = 0

INPUT "Diaframma a tutta apertura: ", av1
ripeti:
INPUT "Tempo a tutta apertura: ", temp1$
IF LEN(temp1$) < 1
GOTO ripeti
endif
temp1$=replace$(temp1$,"//", "/")
IF RIGHT$(temp1$, 1) = "/"
temp1$ = LEFT$(temp1$, LEN(temp1$) - 1)
endif
IF RIGHT$(temp1$, 1) = "."
temp1$ = LEFT$(temp1$, LEN(temp1$) - 1)
endif
IF LEFT$(temp1$, 1) = "/"
temp1$ = RIGHT$(temp1$, LEN(temp1$) - 1)
endif
FOR i = 1 TO LEN(temp1$)
IF MID$(temp1$, i, 1) = "/"
switch = 1
strnum$ = MID$(temp1$, 1, i-1)
strden$ = MID$(temp1$, i + 1, LEN(temp1$) - i)
IF RIGHT$(strnum$, 1) = "."
strnum$ = LEFT$(strnum$, LEN(strnum$) - 1)
endif
IF RIGHT$(strden$, 1) = "."
strden$ = LEFT$(strden$, LEN(strden$) - 1)
endif
IF check(strnum$) = 0
GOTO ripeti
endif
IF check(strden$) = 0
GOTO ripeti
endif
num = VAL(strnum$)
den = VAL(strden$)
numint = INT(num)
denint = INT(den)
tempo1 = numint / denint
Endif
NEXT

IF switch = 1
  ev1 = (pow(av1,2)) / tempo1
  ev1 = log2(ev1)
  array.length lngth, diaframmi[]

  FOR i = 1 TO lngth
    av2 = diaframmi[i]
    IF av2 <> av1
      tempo2 = calculate(ev1,av2)
      IF tempo2 < 2
    tempo2 = 1 / tempo2
    PRINT STR$(tempo2) + " sec @" + STR$(av2)
      ELSE
    PRINT "1/" + STR$(tempo2) + " sec @" + STR$(av2)
      Endif
    endif
  NEXT



ELSEIF switch = 0
  IF check(temp1$) = 0 THEN
    GOTO ripeti
  endif
  tempo1 = VAL(temp1$)
  ev1 = (av1 ^ 2) / tempo1
  ev1 = log2(ev1)
  array.length lngth, diaframmi[]
  FOR i = 1 TO lngth
    av2 = diaframmi[i]
    IF av2 <> av1
      tempo2 = calculate(ev1, av2)
      PRINT STR$(tempo2) + " sec @" + STR$(av2)
    endif
  NEXT
endif

PRINT "by Andrea Verdi ©"
pause 20000
INPUT "Exit? y/n", k$
IF k$ = "y"
END
endif
IF k$ = "Y"
END
endif
GOTO inizio