local Utility = (function()
	local PARAM = RaycastParams.new()

	return {
		voxel_shade = function(normal, light_direction)
			return math.clamp(0.5 + (normal:Dot(light_direction) / 2), 0, 1)
		end,
		in_shadow = function(position, ignore)
			PARAM.FilterDescendantsInstances = {ignore}
			local sunDirection = game.Lighting:GetSunDirection()
			local result = workspace:Raycast(position, sunDirection * 1000, PARAM)
			if result then
				if result.Normal:Dot(sunDirection) < 0 then
					return true
				end
			end
			return false
		end,
		black_and_white = function(color)
			local average = (color.r + color.g + color.b) / 3
			return Color3.new(average, average, average)
		end
	}
end)()
local raytracer_1_0_0 = Instance.new("Tool", owner.Backpack)
raytracer_1_0_0.Name = "Raytracer"
raytracer_1_0_0.ToolTip = "RAYS : 150 , WIDTH : 10 , HEIGHT : 5"
raytracer_1_0_0.Grip = CFrame.new(0.563542724, -0.097826004, 0.377468109, 1, 0, 0, 0, 1, 0, 0, 0, 1)

local handle = Instance.new("MeshPart")
handle.Name = "Handle"
handle.TextureID = "rbxassetid://6318474739"
handle.CFrame = CFrame.new(4.85066462, 7.25513029, 5.45907688, 1, 0, 0, 0, 0.999985516, -0.00537854433, 0, 0.00537854433, 0.999985516)
handle.CanCollide = false
handle.CanQuery = false
handle.CanTouch = false
handle.Massless = true
handle.Rotation = Vector3.new(0.31, 0, 0)
handle.Size = Vector3.new(1.31, 0.896, 0.903)
handle.Parent = raytracer_1_0_0

function newInput(keycode)
	local p = Instance.new("ProximityPrompt", handle)
	p.Style = Enum.ProximityPromptStyle.Custom
	p.MaxActivationDistance = 3
	p.KeyboardKeyCode = keycode
	return p.Triggered
end

local cam = handle
local rays = 150
local width = 10
local height = 5
local FOV = 7


newInput(Enum.KeyCode.Period):Connect(function(p)
	if p ~= owner then return end
	rays += 10
	raytracer_1_0_0.ToolTip = `RAYS : {rays} , WIDTH : {width} , HEIGHT : {height}`
	print(raytracer_1_0_0.ToolTip)
end)
newInput(Enum.KeyCode.Comma):Connect(function(p)
	if p ~= owner then return end
	rays -= 10
	raytracer_1_0_0.ToolTip = `RAYS : {rays} , WIDTH : {width} , HEIGHT : {height}`
	print(raytracer_1_0_0.ToolTip)
end)

function addColor(colors)
	local result = Vector3.new()
	for _, col in colors do 
		result += Vector3.new(col.R, col.G, col.B)
	end
	return result
end

function antiAlias(pixels)
	local antiAliasedPixels = {}
	
	for y, row in pairs(pixels) do
		antiAliasedPixels[y] = {}
		for x, pixel in pairs(row) do
			local topLeft = pixels[y - 1] and pixels[y - 1][x - 1] or pixel
			local top = pixels[y - 1] and pixels[y - 1][x] or pixel
			local topRight = pixels[y - 1] and pixels[y - 1][x + 1] or pixel
			local left = pixels[y] and pixels[y][x - 1] or pixel
			local right = pixels[y] and pixels[y][x + 1] or pixel
			local bottomLeft = pixels[y + 1] and pixels[y + 1][x - 1] or pixel
			local bottom = pixels[y + 1] and pixels[y + 1][x] or pixel
			local bottomRight = pixels[y + 1] and pixels[y + 1][x + 1] or pixel

			local sum = addColor{
				topLeft,
				top,
				topRight,
				left,
				right,
				bottomLeft,
				bottom, 
				bottomRight
			} 
			local antiAliasedValue = sum / 8
			
			antiAliasedPixels[y][x] = Color3.new(antiAliasedValue.X, antiAliasedValue.Y, antiAliasedValue.Z)
		end
	end

	return antiAliasedPixels
end

function colorInThreshold(color1, color2, threshold)
	threshold = threshold or 0.04
	local diff = 0
	local s = "RGB"
	for i = 1, 3 do
		local index = s:sub(i,i)
		diff = diff + (color1[index] - color2[index])^2
	end
	diff = math.sqrt(diff)
	return diff <= threshold
end

local parts = {_size = nil}

raytracer_1_0_0.Activated:Connect(function()
	local origin = cam.CFrame
	local direction = cam.CFrame.LookVector
	local uv = {}
	local pixels = {}
	local start = os.clock()
	local last
	local lx = 0
	local x,y = 0,0
	local spacing = width / (rays - 1)
	local size = spacing
	local ch = script:GetChildren()
	--if parts._size ~= size then
		for i = 1, #ch do 
			if i%300 == 0 then 
				task.wait(0.05)
			end
			ch[i]:Destroy()
		end
	--end
	for i = -height/2, height/2, spacing do
		y += 1
		if i % 6 == 0 then
			task.wait()
		end
		if not pixels[y] then
			pixels[y] = {}
		end
		for j = -width/2, width/2, spacing do
			x += 1 
			lx += 1
			local pos = origin * CFrame.new(j, i, -FOV)

			local dir = (origin.Position - pos.Position).Unit * -1000

			local result = workspace:Raycast(origin.Position, dir)
			if result then 
				local col = result.Instance.Color
				local endColor = col:Lerp(Color3.new(), 1 - Utility.voxel_shade(result.Normal,  game.Lighting:GetSunDirection()))


				if Utility.in_shadow(result.Position, result.Instance) then
					endColor = endColor:Lerp(Color3.new(), 0.4)
				end

				pixels[y][x] = endColor
				last = endColor
			else 
				local col = Color3.fromRGB(128, 187, 219)
				
				local clockTime = game.Lighting.ClockTime
				local mappedValue = math.max(0, (clockTime - 7) / 10)
				
				col = col:Lerp(Color3.new(), 1 - mappedValue)
				
				if game.Lighting.ClockTime > 4 then
					local noise = math.noise(x / 50, y / 40)
					col = col:Lerp(Color3.new(1,1,1), math.clamp(noise - 0.15 + (math.noise(y/20,x/10) / 20),0,1))
				end 
				
				pixels[y][x] = col
				last = col
			end
		end
		x = 0
	end
	--print("done raycasting, "..os.clock() - start)
	start = os.clock()
	--print("anti-aliasing")
	pixels = antiAlias(pixels)
	--print("done AA, "..os.clock() - start)
	start = os.clock()
	--print("rendering")
	parts._size = size
	for y, xdata in ipairs(pixels) do
		local last
		parts[y] = {}
		for x, result in xdata do
			if x % 80 == 0 then
				task.wait()
			end
			if last then 
				if colorInThreshold(last.Color, result) then
					last.Size += Vector3.new(size, 0, 0)
					last.CFrame *= CFrame.new(size/2, 0, 0)
					continue
				end
			end
			if size== parts._size and parts[y][x] then
				parts[y][x].Color = result
				return
			end 
			local tst = Instance.new("Part\0")
			tst.Anchored = true 
			tst.CanCollide = false 
			tst.CanQuery = false 
			tst.Size = Vector3.new(1, 1, 1) * size
			tst.Color = result
			tst.CFrame = origin * CFrame.new(x * tst.Size.Z , y * tst.Size.Y, 0)
			tst.Parent = script
			
			parts[y][x] = tst
			
			last = tst
		end
	end
	--print("done rendering, "..os.clock() - start)
end)