Data commit

Task/Fractal-tree/ZX-Spectrum-Basic/fractal-tree.basic

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+10 LET level=12: LET long=45
+20 LET x=127: LET y=0
+30 LET rotation=PI/2
+40 LET a1=PI/9: LET a2=PI/9
+50 LET c1=0.75: LET c2=0.75
+60 DIM x(level): DIM y(level)
+70 BORDER 0: PAPER 0: INK 4: CLS
+80 GO SUB 100
+90 STOP
+100 REM Tree
+110 LET x(level)=x: LET y(level)=y
+120 GO SUB 1000
+130 IF level=1 THEN GO TO 240
+140 LET level=level-1
+150 LET long=long*c1
+160 LET rotation=rotation-a1
+170 GO SUB 100
+180 LET long=long/c1*c2
+190 LET rotation=rotation+a1+a2
+200 GO SUB 100
+210 LET rotation=rotation-a2
+220 LET long=long/c2
+230 LET level=level+1
+240 LET x=x(level): LET y=y(level)
+250 RETURN
+1000 REM Draw
+1010 LET yn=-SIN rotation*long+y
+1020 LET xn=COS rotation*long+x
+1030 PLOT x,y: DRAW xn-x,y-yn
+1040 LET x=xn: LET y=yn
+1050 RETURN