-- Zeichnet eine linie zwischen start und end
fn drawLine start end = 
(
	l = line pos:start
	addNewSpline l
	addKnot l 1 #corner #line start
	addKnot l 1 #corner #line end
	updateShape l
	l
)

-- produziert aus dem lsystem einen string
fn calcLSystem prod start iterations = (
	string = start
	for i = 1 to iterations do (
		tmp = ""
		for j = 1 to string.count do (
			prodExists = false
			for k = 1 to prod.count do (
				if (string[j] == prod[k][1]) then (
					tmp += prod[k][2]
					prodExists = true
				)
			)
			if(prodExists == false) then (
				tmp += string[j]
			)
		)
		string = tmp
	)
	print string
)

fn drawLSystem prod start iterations startpos startdir angle length  = (
	curpos = startpos
	vec = length * (normalize startdir)
	string = calcLSystem prod start iterations
	lStack = #()
	ln = line pos:curpos
	spline = addNewSpline ln
	addKnot ln spline #corner #line curpos

	for i = 0 to string.count do(
		action = string[i]
		if(action == "F") then(
			-- drawLine curpos (curpos+vec)
			addKnot ln spline #corner #line (curpos + vec)
			curpos = curpos + vec
		)else if(action == "+") then(
			--vec = vec * (rotateYPRMatrix 0 0 angle)
			angle = abs angle
		) else if(action == "-") then(
			--vec = vec * (rotateYPRMatrix 0 0 -angle)
			angle = -(abs angle)
		)else if(action == "A") then(
			-- drawLine curpos (curpos+vec)
			addKnot ln spline #corner #line (curpos + vec)
			curpos = curpos + vec
		)else if(action == "B") then(
			-- drawLine curpos (curpos+vec)
			addKnot ln spline #corner #line (curpos + vec)
			curpos = curpos + vec
		) else if(action == "[") then(
			append lStack #(curpos, vec)
		) else if(action == "]") then(
			curpos = lStack[lStack.count][1]
			vec = lStack[lStack.count][2]
			deleteItem lStack lStack.count
			spline = addnewSpline ln
			-- 2 Knoten hinzufügen damit keine fehler auftreten. ein spline muss zumindest aus einer line bestehen, es ist aber nicht garantiert, dass das lsystem eine linie generiert.
			addKnot ln spline #corner #line curpos
			addKnot ln spline #corner #line curpos
		)else if(action == "y") then(
			vec = vec * (rotateYPRMatrix angle 0 0)
		) else if(action == "p") then(
			vec = vec * (rotateYPRMatrix 0 angle 0)
		) else if(action == "r") then(
			vec = vec * (rotateYPRMatrix 0 0 angle)
		) else(

		)
	)
	
	updateShape ln
)



-- Kuch Curve 1
--prod = #( #("A", "B-rA-rB"), #("B", "A+rB+rA") )
--start = "A"
--lAngle = 60
--startpos = [0,0,0]
--startdir = [1,0,0]

-- Koch Curve 2
--prod = #( #("F", "F+rF-rF-rF+rF") )
--start = "F"
--lAngle = 90
--startpos = [0,0,0]
--startdir = [1,0,0]

-- Koch Curve 3
prod = #(#("F", "F-rF+r+rF-rF"))
start = "F+r+rF+r+rF"
lAngle = 60
startpos = [0,0,0]
startdir = [1,0,0]

-- FractalPlant
--prod = #(#("X", "F-yr[[X]+ryX]+ryF[+ryFX]-ryX"), #("F", "FF"))
--start="X"
--lAngle = 25
--startpos = [0,0,0]
--startdir = [0,0,1]

drawLSystem prod start 3 startpos startdir lAngle 1