init

init.lua

@@ -0,0 +1,105 @@
+local r_corr = 0.25 --remove a bit more nodes (if shooting diagonal) to let it look like a hole (sth like antialiasing)
+
+-- this doesn't need to be calculated every time
+local f_1 = 0.5-r_corr
+local f_2 = 0.5+r_corr
+
+--returns information about the direction
+local function get_used_dir(dir)
+	local abs_dir = {x=math.abs(dir.x), y=math.abs(dir.y), z=math.abs(dir.z)}
+	local dir_max = math.max(abs_dir.x, abs_dir.y, abs_dir.z)
+	if dir_max == abs_dir.x then
+		local tab = {"x", {x=1, y=dir.y/dir.x, z=dir.z/dir.x}}
+		if dir.x >= 0 then
+			tab[3] = "+"
+		end
+		return tab
+	end
+	if dir_max == abs_dir.y then
+		local tab = {"y", {x=dir.x/dir.y, y=1, z=dir.z/dir.y}}
+		if dir.y >= 0 then
+			tab[3] = "+"
+		end
+		return tab
+	end
+	local tab = {"z", {x=dir.x/dir.z, y=dir.y/dir.z, z=1}}
+	if dir.z >= 0 then
+		tab[3] = "+"
+	end
+	return tab
+end
+
+local function node_tab(z, d)
+	local n1 = math.floor(z*d+f_1)
+	local n2 = math.floor(z*d+f_2)
+	if n1 == n2 then
+		return {n1}
+	end
+	return {n1, n2}
+end
+
+local function return_line(pos, dir, range) --range ~= length
+	local tab = {}
+	local num = 1
+	local t_dir = get_used_dir(dir)
+	local dir_typ = t_dir[1]
+	if t_dir[3] == "+" then
+		f_tab = {0, range, 1}
+	else
+		f_tab = {0, -range, -1}
+	end
+	local d_ch = t_dir[2]
+	if dir_typ == "x" then
+		for d = f_tab[1],f_tab[2],f_tab[3] do
+			local x = d
+			local ytab = node_tab(d_ch.y, d)
+			local ztab = node_tab(d_ch.z, d)
+			for _,y in ipairs(ytab) do
+				for _,z in ipairs(ztab) do
+					tab[num] = {x=pos.x+x, y=pos.y+y, z=pos.z+z}
+					num = num+1
+				end
+			end
+		end
+	elseif dir_typ == "y" then
+		for d = f_tab[1],f_tab[2],f_tab[3] do
+			local xtab = node_tab(d_ch.x, d)
+			local y = d
+			local ztab = node_tab(d_ch.z, d)
+			for _,x in ipairs(xtab) do
+				for _,z in ipairs(ztab) do
+					tab[num] = {x=pos.x+x, y=pos.y+y, z=pos.z+z}
+					num = num+1
+				end
+			end
+		end
+	else
+		for d = f_tab[1],f_tab[2],f_tab[3] do
+			local xtab = node_tab(d_ch.x, d)
+			local ytab = node_tab(d_ch.y, d)
+			local z = d
+			for _,x in ipairs(xtab) do
+				for _,y in ipairs(ytab) do
+					tab[num] = {x=pos.x+x, y=pos.y+y, z=pos.z+z}
+					num = num+1
+				end
+			end
+		end
+	end
+	return tab
+end
+
+function vector.line(pos, dir, range)
+	--assert_vector(pos)
+	if not range then --dir = pos2
+		return return_line(pos, vector.direction(pos, dir), vector.distance(pos, dir))
+	end
+	return return_line(pos, dir, range)
+end
+
+function vector.straightdelay(s, v, a)
+	if not a then
+		return s/v
+	end
+	return (math.sqrt(v*v+2*a*s)-v)/a
+end