Dragon curve: Difference between revisions

Line 977:

==={{header|QuickBASIC}}===

{{trans|GW-BASIC|Introduced some parameters in the recursive subroutine (especially for a level and instead of the array simulating a stack).}}

REM Dragon curve

REM SIN, COS in arrays for PI/4 multipl.

DECLARE SUB Dragon ()

DECLARE SUB Dragon (BYVAL Insize!, BYVAL Level%, BYVAL RQ%)

DIM SHARED S(7), C(7), X, Y, RotQPi%~~, Level%, Insize, RQ%, SQ~~

DIM SHARED S(7), C(7), X, Y, RotQPi%

CONST QPI = .785398163397448# ' PI / 4

QPi = ATN(1)

SQ = SQR(2)

FOR I = 0 TO 7

S(I) = SIN(I * ~~QPi~~)

S(I) = SIN(I * QPI)

C(I) = COS(I * ~~QPi~~)

C(I) = COS(I * QPI)

NEXT I

Level% = 15

⚫

~~Insize =~~ 128: ~~REM~~ 2^WHOLE_NUM (looks better)

X = 112: Y = 70

RotQPi% = 0: RQ% = 1

DIM SHARED R%(Level%)

SCREEN 2: CLS

⚫

CALL Dragon(128, 15, 1) ' Insize = 2^WHOLE_NUM (looks better)

CALL Dragon

END

SUB Dragon (BYVAL Insize, BYVAL Level%, BYVAL RQ%)

SUB Dragon

CONST SQ = 1.4142135623731# ' SQR(2)

RotQPi% = RotQPi% AND 7

IF Level% <= 1 THEN

⚫

YN = S(RotQPi%) * Insize + Y

XN = C(RotQPi%) * Insize + X

⚫

YN = S(RotQPi%) * Insize + Y

LINE (2 * X, Y)-(2 * XN, YN): ~~REM~~ For SCREEN 2 doubled x-coords

LINE (2 * X, Y)-(2 * XN, YN) ' For SCREEN 2 doubled x-coords

X = XN: Y = YN

ELSE

Insize = Insize * SQ / 2

RotQPi% = (RotQPi% + RQ%) AND 7

~~Level%~~ = Level% - 1

CALL Dragon(Insize / SQ, Level% - 1, 1)

R%~~(Level%)~~ = RQ%: RQ% = 1

RotQPi% = (RotQPi% - RQ% * 2) AND 7

CALL Dragon

CALL Dragon(Insize / SQ, Level% - 1, -1)

RotQPi% = (RotQPi% - R%(Level%) * 2) AND 7

RQ% = -1

CALL Dragon

RQ% = R%(Level%)

RotQPi% = (RotQPi% + RQ%) AND 7

Level% = Level% + 1

Insize = Insize * SQ

END IF

END SUB