i, r, n1, n2, lineix, lineiy, linerx, linery, lineixw, lineiyw, d, h, lambda = 45, 28.12, 1, 1.5, 50, 0, 228, 220, 270, 0, 168.41, 89.99, 41.81
setn1, setn2, seti = false, false ,false
input=""

function setn1()
	setn1 = true
	platform.window:invalidate()
end

function setn2()
	setn2 = true
	platform.window:invalidate()
end

function seti()
	seti = true
	platform.window:invalidate()
end

function on.paint(gc)

	r = math.floor(math.asin(n1*math.sin(i/360*2*math.pi)/n2)*100/(2*math.pi)*360)/100
	i = math.floor(i*100)/100
	n1 = math.floor(n1*1000)/1000
	n2 = math.floor(n2*1000)/1000
	h = math.floor(math.tan(math.pi/2-i/360*2*math.pi)*90*100)/100
	d = math.floor(math.tan(math.pi/2-r/360*2*math.pi)*90*100)/100

	if i<=45 then
		lineix = 160 - 22*i/9
		lineiy = 0
		lineixw = 160 + 22*i/9
		lineiyw = 0
	else
		lineiy = 22*i/9 - 110
		lineix = 50
		lineiyw = 22*i/9 - 110
		lineixw = 270
	end
	if r<=45 then
		linerx = 160 + 22*r/9
		linery = 220
	else
		linery = 220+(110-22*r/9)
		linerx = 270
	end
	if n1 >= n2 then
		lambda = math.asin(n2/n1)/(2*math.pi)*360
	else
		lambda = math.asin(n1/n2)/(2*math.pi)*360
	end
	gc:setFont("sansserif","r","6")	
	gc:setColorRGB(3,142,250)						--blauw
	gc:fillRect(0,110,320,110)						--rechthoek
	gc:setColorRGB(200,200,200)						--grijs
	gc:drawArc(140,90,40,40,90-i,i)						--hoekaanduiding weerk
	gc:drawLine(lineixw,lineiyw,160,110)					--weerkaatste straal
	gc:drawLine(160,110,lineixw,220-lineiyw)				--doorloping invallende straal
	--gc:drawLine(250,100,250,220)						--vert lijn voor schijnb diepte
	gc:setColorRGB(0,0,0)							--zwart
	gc:drawLine(0,110,320,110)						--scheidingslijn stoffen
	gc:drawLine(160,0,160,220)						--normaal lijn
	gc:drawString("n1: "..math.floor(n1*1000)/1000,15,195,"top")		--print n1
	gc:drawString("n2: "..math.floor(n2*1000)/1000,95,195,"top")		--print n2
	gc:drawString("i: "..i,190,195,"top")					--print invallende hoek
	gc:drawString("normal",162,0,"top")					--print "normal"
	gc:drawString("n1",1,92,"top")						--print middenstof n1
	gc:drawString("n2",1,112,"top")						--print middenstof n2
	gc:drawLine(lineix,lineiy,160,110)					--invallende straal

	if i<=lambda then
		gc:drawLine(linerx,linery,160,110)				--brekingsstraal
		gc:drawArc(140,90,40,40,-90,r)					--hoekaanduiding brekingsstraal
		gc:drawString("r: "..r,260,195,"top")				--print brekingshoek
	else
		gc:drawString("Total refl.",260,195,"top")
	end

	--gc:drawString("d = "..d,252,108,"top")					--print schijnb diepte
	--gc:drawString("h = "..h,252,116,"top")					--print echte diepte
	gc:drawString("Lambda = "..math.floor(lambda*100)/100,1,1,"top")		--max hoek
	
	gc:drawArc(140,90,40,40,90,i)						--hoekaanduiding invallende straal

	if seti or setn1 or setn2 then
		if seti then
			gc:drawString("i=",1,20,"top")
		end
		if setn1 then
			gc:drawString("n1=",1,20,"top")
		end
		if setn2 then
			gc:drawString("n2=",1,20,"top")
		end
		gc:setColorRGB(255,255,255)
		gc:fillRect(25,20,40,16)
		gc:setColorRGB(0,0,0)
		gc:drawRect(25,20,40,16)
		gc:setFont("sansserif","r","6")
		gc:drawString(input,27,20,"top")
	end
end

function on.enterKey()
	if seti or setn1 or setn2 then
		seti = false
		setn1 = false
		setn2 = false
		input = ""
	end
	platform.window:invalidate()
end

function on.activate()
	r = math.floor(math.asin(n1*math.sin(i/360*2*math.pi)/n2)*100/(2*math.pi)*360)/100
	i = (var.recall("inputi") or math.floor(i))
	n1 = (var.recall("inputn1") or math.floor(n1*1000)/1000)
	n2 = (var.recall("inputn2") or math.floor(n2*1000)/1000)
	--h = math.floor(math.tan(r)*d/math.tan(i)*100)/100
	--h = math.floor(math.tan(math.pi/2-i/360*2*math.pi)*90*100)/100
	--d = math.floor(math.tan(math.pi/2-r/360*2*math.pi)*90*100)/100
	platform.window:invalidate()
end

function on.charIn(char)	
	
	if seti then
		if char == '1' or char == '2' or char == '3' or char == '4' or char == '5' or char == '6' or char == '7'or char == '8' or char == '9' or char == '0' or char == '.' then
			if char == '.' and string.len(input) == 0 then
				input = input.."0"
			end
			input = input..char
			if tonumber(input) >= 90 then
				input = "90"
			end
			platform.window:invalidate()
		end
		if input == "" then
			i = 0
		else
			i = tonumber(input)
		end
	end
	if setn1 then
		if char == '1' or char == '2' or char == '3' or char == '4' or char == '5' or char == '6' or char == '7'or char == '8' or char == '9' or char == '0' or char == '.' then
			if char == '.' and string.len(input) == 0 then
				input = input.."0"
			end
			if string.len(input)<=9 then
				input = input..char
			end
			platform.window:invalidate()
		end
		if input == "" then
			n1 = 0
		else
			n1 = tonumber(input)
		end
	end
	if setn2 then
		if char == '1' or char == '2' or char == '3' or char == '4' or char == '5' or char == '6' or char == '7'or char == '8' or char == '9' or char == '0' or char == '.' then
			if char == '.' and string.len(input) == 0 then
				input = input.."0"
			end
			if string.len(input)<=9 then
				input = input..char
			end
			platform.window:invalidate()
		end
		if input == "" then
			n2 = 0
		else
			n2 = tonumber(input)
		end
	end
end

function on.tabKey()								--[tab] reset alles
	i, r, n1, n2, lineix, lineiy, linerx, linery, lineixw, lineiyw, d, h, lambda = 45, 28.12, 1, 1.5, 50, 0, 232, 220, 270, 0, 168.41, 89.99, 0
	platform.window:invalidate()						--scherm printen
end

function on.backspaceKey()
	if seti or setn1 or setn2 then
		input = string.usub(input,0,string.len(input)-1)
	end
	if seti then
		if input == "" then
			i = 0
		else
			i = tonumber(input)
		end
	end
	if setn1 then
		if input == "" then
			n1 = 0
		else
			n1 = tonumber(input)
		end
	end
	if setn2 then
		if input == "" then
			n2 = 0
		else
			n2 = tonumber(input)
		end
	end
	platform.window:invalidate()
end

menu = {

	{"Change values",
		{"n1", setn1},
		{"n2", setn2},
		{"i", seti},
	}
}
 
toolpalette.register(menu)

setn1, setn2, seti = false, false ,false