SCREEN 12

RANDOMIZE (TIMER)

pi = 4 * ATN(1)

tau = (SQR(5) + 1) / 2

cosatntau = COS(ATN(tau)): REM approx. .525731112
sinatntau = SIN(ATN(tau)): REM approx. .850650808
height1 = cosatntau / 2: REM approx. .252865556
height2 = height1 + sinatntau: REM approx. 1.113516364
radius1 = sinatntau: REM approx. .850650808
radius2 = radius1 * tau: REM approx. 1.37638102

scale = 150

xxcentre = 319 + 93
yycentre = 239 + 17


theta = 18
thetarad = theta * pi / 180

REM phi = ATN(SQR(2))
phi = 63.1
phi = 37.5: REM gives elevation of 52.5ø. artan((tau+1)/2) = 52.62263186ø.
REM             With theta = 18ø, appears to give view directly over vertex.
phirad = phi * pi / 180

DIM angle(9)

FOR i = 0 TO 9
    angle(i) = 2 * pi * i / 10
NEXT i

DIM x(20), y(20), Z(20), xx(20), yy(20)

FOR i = 1 TO 10
    x(i) = COS((3 + 2 * i) * pi / 5)
    y(i) = SIN((3 + 2 * i) * pi / 5)
NEXT i

FOR i = 11 TO 20
    x(i) = COS(pi + (3 + 2 * i) * pi / 5)
    y(i) = SIN(pi + (3 + 2 * i) * pi / 5)
NEXT i

FOR i = 1 TO 20
    IF i < 6 OR i > 15 THEN
        x(i) = x(i) * radius1
        y(i) = y(i) * radius1
    ELSE
        x(i) = x(i) * radius2
        y(i) = y(i) * radius2
    END IF
NEXT i

FOR i = 6 TO 10
    Z(i) = height1
NEXT i

FOR i = 1 TO 5
    Z(i) = height2
NEXT i

FOR i = 11 TO 20
    Z(i) = -Z(21 - i)
NEXT i

bottomcolour = 4: REM red
lowerstrutscolour = 14: REM yellow
tropicalbandcolour = 2: REM green
upperstrutscolour = 9: REM light blue
topcolour = 13: REM light magenta

GOSUB workoutcoordinates

GOSUB drawdode

COLOR 7
LOCATE 1, 1: PRINT "theta =        degrees   Press L or R arrow keys to spin             "; : COLOR 12: PRINT "Esc to quit": COLOR 7
LOCATE 2, 1: PRINT "elev. =        degrees   Press U or D arrow keys to change elevation"
LOCATE 3, 26: PRINT "(Ctrl => 0.25ø movements; Alt => 4ø movements)"
LOCATE 1, 9: PRINT "      "
LOCATE 1, 9: PRINT theta
LOCATE 2, 9: PRINT "      "
LOCATE 2, 9: PRINT 90 - phi

LOCATE 12, 2: PRINT "EDGE LENGTH:"
LOCATE 13, 6: PRINT "pixels"
LOCATE 13, 1: PRINT scale
LOCATE 14, 2: PRINT "(Max. = 150)"
LOCATE 16, 2: PRINT "Z zooms in"
LOCATE 17, 2: PRINT "X zooms out"
LOCATE 19, 2: PRINT "(Shift =>"
LOCATE 20, 2: PRINT "10 pixels"
LOCATE 21, 2: PRINT "at a time)"


LOCATE 30, 1: PRINT "         artan 2 ÷ 63.5ø      artan û2 ÷ 54.75ø      artan tau ÷ 58.25ø";


COLOR 6
LOCATE 6, 1: PRINT "REGULAR DODECAHEDRON ANIMATION"
LOCATE 8, 1: PRINT "Copyright (c) 2005"
LOCATE 9, 1: PRINT "by Mad Teddy"

COLOR 7


a$ = ""

DO UNTIL a$ = CHR$(27)

    a$ = INKEY$
    IF a$ <> "" THEN
        a$ = RIGHT$(a$, 1)
        IF a$ = CHR$(141) AND phi > 0 THEN
            phi = phi - .25
            IF phi <= 0 THEN
                BEEP
                phi = 0
            END IF
            phirad = phi * pi / 180
        ELSEIF a$ = CHR$(72) AND phi > 0 THEN
            phi = phi - 1
            IF phi <= 0 THEN
                BEEP
                phi = 0
            END IF
            phirad = phi * pi / 180
        ELSEIF a$ = CHR$(152) AND phi > 0 THEN
            phi = phi - 4
            IF phi <= 0 THEN
                BEEP
                phi = 0
            END IF
            phirad = phi * pi / 180
        ELSEIF a$ = CHR$(145) AND phi < 90 THEN
            phi = phi + .25
            IF phi >= 90 THEN
                BEEP
                phi = 90
            END IF
            phirad = phi * pi / 180
        ELSEIF a$ = CHR$(80) AND phi < 90 THEN
            phi = phi + 1
            IF phi >= 90 THEN
                BEEP
                phi = 90
            END IF
            phirad = phi * pi / 180
        ELSEIF a$ = CHR$(160) AND phi < 90 THEN
            phi = phi + 4
            IF phi >= 90 THEN
                BEEP
                phi = 90
            END IF
            phirad = phi * pi / 180
        ELSEIF a$ = CHR$(115) THEN
            IF theta = 0 THEN
                theta = 71.75
            ELSE
                theta = theta - .25
            END IF
            thetarad = theta * pi / 180
        ELSEIF a$ = CHR$(75) THEN
            IF theta < 1 THEN
                theta = theta + 72
            END IF
                theta = theta - 1
            thetarad = theta * pi / 180
        ELSEIF a$ = CHR$(155) THEN
            IF theta < 4 THEN
                theta = theta + 72
            END IF
                theta = theta - 4
            thetarad = theta * pi / 180
        ELSEIF a$ = CHR$(116) THEN
            IF theta = 71.75 THEN
                theta = 0
            ELSE
                theta = theta + .25
            END IF
            thetarad = theta * pi / 180
        ELSEIF a$ = CHR$(77) THEN
            IF theta >= 71 THEN
                theta = theta - 72
            END IF
                theta = theta + 1
            thetarad = theta * pi / 180
        ELSEIF a$ = CHR$(157) THEN
            IF theta >= 68 THEN
                theta = theta - 72
            END IF
                theta = theta + 4
            thetarad = theta * pi / 180
        ELSEIF a$ = "z" AND scale < 150 THEN
            scale = scale + 1
        ELSEIF a$ = "Z" AND scale < 150 THEN
            scale = scale + 10
            IF scale > 150 THEN
                BEEP
                scale = 150
            END IF
        ELSEIF a$ = "x" AND scale > 0 THEN
            scale = scale - 1
        ELSEIF a$ = "X" AND scale > 0 THEN
            scale = scale - 10
            IF scale < 0 THEN
                BEEP
                scale = 0
            END IF
        END IF

        IF a$ = CHR$(115) OR a$ = CHR$(75) OR a$ = CHR$(155) OR a$ = CHR$(116) OR a$ = CHR$(77) OR a$ = CHR$(157) THEN
            LOCATE 1, 9: PRINT "      "
            LOCATE 1, 9: PRINT theta
        ELSEIF a$ = CHR$(141) OR a$ = CHR$(72) OR a$ = CHR$(152) OR a$ = CHR$(145) OR a$ = CHR$(80) OR a$ = CHR$(160) THEN
            LOCATE 2, 9: PRINT "      "
            LOCATE 2, 9: PRINT 90 - phi
        ELSEIF a$ = "z" OR a$ = "Z" OR a$ = "x" OR a$ = "X" THEN
            LOCATE 13, 1: PRINT scale
        END IF

    END IF


REM    FOR j = 1 TO 10000
REM    NEXT j

    IF a$ = CHR$(115) OR a$ = CHR$(75) OR a$ = CHR$(155) OR a$ = CHR$(116) OR a$ = CHR$(77) OR a$ = CHR$(157) OR a$ = CHR$(141) OR a$ = CHR$(72) OR a$ = CHR$(152) OR a$ = CHR$(145) OR a$ = CHR$(80) OR a$ = CHR$(160) OR a$ = "z" OR a$ = "Z" OR a$ =  _
"x" OR a$ = "X" THEN

        GOSUB erasedode

        REM GOSUB drawaxes

        GOSUB workoutcoordinates

        GOSUB drawdode

    END IF

LOOP

END

REM *** SUBROUTINES ***


drawdode:

REM bottom

LINE (xxcentre + xx(16), yycentre - yy(16))-(xxcentre + xx(17), yycentre - yy(17)), bottomcolour
LINE (xxcentre + xx(17), yycentre - yy(17))-(xxcentre + xx(18), yycentre - yy(18)), bottomcolour
LINE (xxcentre + xx(18), yycentre - yy(18))-(xxcentre + xx(19), yycentre - yy(19)), bottomcolour
LINE (xxcentre + xx(19), yycentre - yy(19))-(xxcentre + xx(20), yycentre - yy(20)), bottomcolour
LINE (xxcentre + xx(20), yycentre - yy(20))-(xxcentre + xx(16), yycentre - yy(16)), bottomcolour

REM lower struts

LINE (xxcentre + xx(16), yycentre - yy(16))-(xxcentre + xx(11), yycentre - yy(11)), lowerstrutscolour
LINE (xxcentre + xx(17), yycentre - yy(17))-(xxcentre + xx(12), yycentre - yy(12)), lowerstrutscolour
LINE (xxcentre + xx(18), yycentre - yy(18))-(xxcentre + xx(13), yycentre - yy(13)), lowerstrutscolour
LINE (xxcentre + xx(19), yycentre - yy(19))-(xxcentre + xx(14), yycentre - yy(14)), lowerstrutscolour
LINE (xxcentre + xx(20), yycentre - yy(20))-(xxcentre + xx(15), yycentre - yy(15)), lowerstrutscolour

REM tropical band

LINE (xxcentre + xx(6), yycentre - yy(6))-(xxcentre + xx(14), yycentre - yy(14)), tropicalbandcolour
LINE (xxcentre + xx(14), yycentre - yy(14))-(xxcentre + xx(7), yycentre - yy(7)), tropicalbandcolour
LINE (xxcentre + xx(7), yycentre - yy(7))-(xxcentre + xx(15), yycentre - yy(15)), tropicalbandcolour
LINE (xxcentre + xx(15), yycentre - yy(15))-(xxcentre + xx(8), yycentre - yy(8)), tropicalbandcolour
LINE (xxcentre + xx(8), yycentre - yy(8))-(xxcentre + xx(11), yycentre - yy(11)), tropicalbandcolour
LINE (xxcentre + xx(11), yycentre - yy(11))-(xxcentre + xx(9), yycentre - yy(9)), tropicalbandcolour
LINE (xxcentre + xx(9), yycentre - yy(9))-(xxcentre + xx(12), yycentre - yy(12)), tropicalbandcolour
LINE (xxcentre + xx(12), yycentre - yy(12))-(xxcentre + xx(10), yycentre - yy(10)), tropicalbandcolour
LINE (xxcentre + xx(10), yycentre - yy(10))-(xxcentre + xx(13), yycentre - yy(13)), tropicalbandcolour
LINE (xxcentre + xx(13), yycentre - yy(13))-(xxcentre + xx(6), yycentre - yy(6)), tropicalbandcolour

REM upper struts

LINE (xxcentre + xx(6), yycentre - yy(6))-(xxcentre + xx(1), yycentre - yy(1)), upperstrutscolour
LINE (xxcentre + xx(7), yycentre - yy(7))-(xxcentre + xx(2), yycentre - yy(2)), upperstrutscolour
LINE (xxcentre + xx(8), yycentre - yy(8))-(xxcentre + xx(3), yycentre - yy(3)), upperstrutscolour
LINE (xxcentre + xx(9), yycentre - yy(9))-(xxcentre + xx(4), yycentre - yy(4)), upperstrutscolour
LINE (xxcentre + xx(10), yycentre - yy(10))-(xxcentre + xx(5), yycentre - yy(5)), upperstrutscolour

REM top

LINE (xxcentre + xx(1), yycentre - yy(1))-(xxcentre + xx(2), yycentre - yy(2)), topcolour
LINE (xxcentre + xx(2), yycentre - yy(2))-(xxcentre + xx(3), yycentre - yy(3)), topcolour
LINE (xxcentre + xx(3), yycentre - yy(3))-(xxcentre + xx(4), yycentre - yy(4)), topcolour
LINE (xxcentre + xx(4), yycentre - yy(4))-(xxcentre + xx(5), yycentre - yy(5)), topcolour
LINE (xxcentre + xx(5), yycentre - yy(5))-(xxcentre + xx(1), yycentre - yy(1)), topcolour

RETURN


erasedode:

REM bottom

LINE (xxcentre + xx(16), yycentre - yy(16))-(xxcentre + xx(17), yycentre - yy(17)), 0
LINE (xxcentre + xx(17), yycentre - yy(17))-(xxcentre + xx(18), yycentre - yy(18)), 0
LINE (xxcentre + xx(18), yycentre - yy(18))-(xxcentre + xx(19), yycentre - yy(19)), 0
LINE (xxcentre + xx(19), yycentre - yy(19))-(xxcentre + xx(20), yycentre - yy(20)), 0
LINE (xxcentre + xx(20), yycentre - yy(20))-(xxcentre + xx(16), yycentre - yy(16)), 0

REM lower struts

LINE (xxcentre + xx(16), yycentre - yy(16))-(xxcentre + xx(11), yycentre - yy(11)), 0
LINE (xxcentre + xx(17), yycentre - yy(17))-(xxcentre + xx(12), yycentre - yy(12)), 0
LINE (xxcentre + xx(18), yycentre - yy(18))-(xxcentre + xx(13), yycentre - yy(13)), 0
LINE (xxcentre + xx(19), yycentre - yy(19))-(xxcentre + xx(14), yycentre - yy(14)), 0
LINE (xxcentre + xx(20), yycentre - yy(20))-(xxcentre + xx(15), yycentre - yy(15)), 0

REM tropical band

LINE (xxcentre + xx(6), yycentre - yy(6))-(xxcentre + xx(14), yycentre - yy(14)), 0
LINE (xxcentre + xx(14), yycentre - yy(14))-(xxcentre + xx(7), yycentre - yy(7)), 0
LINE (xxcentre + xx(7), yycentre - yy(7))-(xxcentre + xx(15), yycentre - yy(15)), 0
LINE (xxcentre + xx(15), yycentre - yy(15))-(xxcentre + xx(8), yycentre - yy(8)), 0
LINE (xxcentre + xx(8), yycentre - yy(8))-(xxcentre + xx(11), yycentre - yy(11)), 0
LINE (xxcentre + xx(11), yycentre - yy(11))-(xxcentre + xx(9), yycentre - yy(9)), 0
LINE (xxcentre + xx(9), yycentre - yy(9))-(xxcentre + xx(12), yycentre - yy(12)), 0
LINE (xxcentre + xx(12), yycentre - yy(12))-(xxcentre + xx(10), yycentre - yy(10)), 0
LINE (xxcentre + xx(10), yycentre - yy(10))-(xxcentre + xx(13), yycentre - yy(13)), 0
LINE (xxcentre + xx(13), yycentre - yy(13))-(xxcentre + xx(6), yycentre - yy(6)), 0

REM upper struts

LINE (xxcentre + xx(6), yycentre - yy(6))-(xxcentre + xx(1), yycentre - yy(1)), 0
LINE (xxcentre + xx(7), yycentre - yy(7))-(xxcentre + xx(2), yycentre - yy(2)), 0
LINE (xxcentre + xx(8), yycentre - yy(8))-(xxcentre + xx(3), yycentre - yy(3)), 0
LINE (xxcentre + xx(9), yycentre - yy(9))-(xxcentre + xx(4), yycentre - yy(4)), 0
LINE (xxcentre + xx(10), yycentre - yy(10))-(xxcentre + xx(5), yycentre - yy(5)), 0

REM top

LINE (xxcentre + xx(1), yycentre - yy(1))-(xxcentre + xx(2), yycentre - yy(2)), 0
LINE (xxcentre + xx(2), yycentre - yy(2))-(xxcentre + xx(3), yycentre - yy(3)), 0
LINE (xxcentre + xx(3), yycentre - yy(3))-(xxcentre + xx(4), yycentre - yy(4)), 0
LINE (xxcentre + xx(4), yycentre - yy(4))-(xxcentre + xx(5), yycentre - yy(5)), 0
LINE (xxcentre + xx(5), yycentre - yy(5))-(xxcentre + xx(1), yycentre - yy(1)), 0

RETURN


drawaxes:

LINE (xxcentre, 0)-(xxcentre, 479), 8
LINE (0, yycentre)-(639, yycentre), 8

RETURN


workoutcoordinates:

FOR i = 1 TO 20
    xx(i) = (x(i) * COS(thetarad) - y(i) * SIN(thetarad)) * scale
    yy(i) = ((x(i) * SIN(thetarad) + y(i) * COS(thetarad)) * COS(phirad) + Z(i) * SIN(phirad)) * scale
    REM PSET (xxcentre + xx(i), yycentre - yy(i)), 15
NEXT i

RETURN