PROGRAM LSYS_PEANO_CURVE_H   !( © W.Van Duyn 24thApril 2004)
SET WINDOW 0,1199,0,903
SET background color "white"
SET color 0
PRINT"Number of iterations try 1,2,3,4,5,6,7 size try 800"
INPUT depth,size
CLEAR
SET COLOR MIX (100)0.9,0.9,0.9   !light gray
SET COLOR MIX (200)0.8,0.1,0.8   !light magenta
LET x=(1200-size)/2
LET y=(900-size)/2
LET w=((3^depth)-1)
LET h=size/w
LET k=90
LET a=0
CALL grid(w,h)
SET color 200
CALL lsysX(depth,h,a,k,r,x,y)
END
SUB lsysX(depth,h,a,k,r,x,y)
IF depth=0 THEN
EXIT IF
ELSE
CALL lsysX(depth-1,h,a,k,r,x,y)
CALL moveON(h,x,y,a)
CALL lsysY(depth-1,h,a,k,r,x,y)
CALL moveON(h,x,y,a)
CALL lsysX(depth-1,h,a,k,r,x,y)
CALL turnLEFT(a,k)
CALL moveON(h,x,y,a)
CALL turnLEFT(a,k)
CALL lsysY(depth-1,h,a,k,r,x,y)
CALL moveON(h,x,y,a)
CALL lsysX(depth-1,h,a,k,r,x,y)
CALL moveON(h,x,y,a)
CALL lsysY(depth-1,h,a,k,r,x,y)
CALL turnRIGHT(a,k)
CALL moveON(h,x,y,a)
CALL turnRIGHT(a,k)
CALL lsysX(depth-1,h,a,k,r,x,y)
CALL moveON(h,x,y,a)
CALL lsysY(depth-1,h,a,k,r,x,y)
CALL moveON(h,x,y,a)
CALL lsysX(depth-1,h,a,k,r,x,y)
END IF
END SUB

SUB lsysY(depth,h,a,k,r,x,y)
IF depth=0 THEN
EXIT IF
ELSE
CALL lsysY(depth-1,h,a,k,r,x,y)
CALL moveON(h,x,y,a)
CALL lsysX(depth-1,h,a,k,r,x,y)
CALL moveON(h,x,y,a)
CALL lsysY(depth-1,h,a,k,r,x,y)
CALL turnRIGHT(a,k)
CALL moveON(h,x,y,a)
CALL turnRIGHT(a,k)
CALL lsysX(depth-1,h,a,k,r,x,y)
CALL moveON(h,x,y,a)
CALL lsysY(depth-1,h,a,k,r,x,y)
CALL moveON(h,x,y,a)
CALL lsysX(depth-1,h,a,k,r,x,y)
CALL turnLEFT(a,k)
CALL moveON(h,x,y,a)
CALL turnLEFT(a,k)
CALL lsysY(depth-1,h,a,k,r,x,y)
CALL moveON(h,x,y,a)
CALL lsysX(depth-1,h,a,k,r,x,y)
CALL moveON(h,x,y,a)
CALL lsysY(depth-1,h,a,k,r,x,y)
END IF
END SUB

SUB moveON(h,x,y,a)
OPTION ANGLE degrees
LET dx=h*cos(a)
LET dy=h*sin(a)
PLOT x,y;x+dx,y+dy
LET x=x+dx
LET y=y+dy
END SUB

SUB turnLEFT(a,k)
LET a=a+k
END SUB

SUB turnRIGHT(a,k)
LET a=a-k
END SUB

SUB grid(w,h)
SET COLOR 100
LET dxy=(w+1)*h
LET dx=600+h*(w+1)/2
LET dy=450+h*(w+1)/2
LET x1=x0
LET y1=y0
FOR k = 0 to w+1
PLOT x1+dx,y0+dy; x1+dx-dxy,y0+dy
PLOT x0+dx,y1+dy; x0+dx,y1+dy-dxy
LET x0=x0-h
LET y0=y0-h
NEXT k
END SUB