From 9462a53338491a5ea3337354266a69d880ecff42 Mon Sep 17 00:00:00 2001
From: ABJ-MV <abjinah@gmail.com>
Date: Tue, 19 May 2015 21:21:29 +0500
Subject: [PATCH] Create functions.lua

---
 mods/hicarts/functions.lua | 150 +++++++++++++++++++++++++++++++++++++
 1 file changed, 150 insertions(+)
 create mode 100644 mods/hicarts/functions.lua

diff --git a/mods/hicarts/functions.lua b/mods/hicarts/functions.lua
new file mode 100644
index 0000000..0bc27e6
--- /dev/null
+++ b/mods/hicarts/functions.lua
@@ -0,0 +1,150 @@
+function hicarts:get_sign(z)
+	if z == 0 then
+		return 0
+	else
+		return z / math.abs(z)
+	end
+end
+
+function hicarts:velocity_to_dir(v)
+	if math.abs(v.x) > math.abs(v.z) then
+		return {x=hicarts:get_sign(v.x), y=hicarts:get_sign(v.y), z=0}
+	else
+		return {x=0, y=hicarts:get_sign(v.y), z=hicarts:get_sign(v.z)}
+	end
+end
+
+function hicarts:is_rail(pos, railtype)
+	local node = minetest.get_node(pos).name
+	if node == "ignore" then
+		local vm = minetest.get_voxel_manip()
+		local emin, emax = vm:read_from_map(pos, pos)
+		local area = VoxelArea:new{
+			MinEdge = emin,
+			MaxEdge = emax,
+		}
+		local data = vm:get_data()
+		local vi = area:indexp(pos)
+		node = minetest.get_name_from_content_id(data[vi])
+	end
+	if minetest.get_item_group(node, "rail") == 0 then
+		return false
+	end
+	if not railtype then
+		return true
+	end
+	return minetest.get_item_group(node, "connect_to_raillike") == railtype
+end
+
+function hicarts:check_front_up_down(pos, dir_, check_down, railtype)
+	local dir = vector.new(dir_)
+	local cur = nil
+	
+	-- Front
+	dir.y = 0
+	cur = vector.add(pos, dir)
+	if hicarts:is_rail(cur, railtype) then
+		return dir
+	end
+	-- Up
+	if check_down then
+		dir.y = 1
+		cur = vector.add(pos, dir)
+		if hicarts:is_rail(cur, railtype) then
+			return dir
+		end
+	end
+	-- Down
+	dir.y = -1
+	cur = vector.add(pos, dir)
+	if hicarts:is_rail(cur, railtype) then
+		return dir
+	end
+	return nil
+end
+
+function hicarts:get_rail_direction(pos_, dir, ctrl, old_switch, railtype)
+	local pos = vector.round(pos_)
+	local cur = nil
+	local left_check, right_check = true, true
+	
+	-- Check left and right
+	local left = {x=0, y=0, z=0}
+	local right = {x=0, y=0, z=0}
+	if dir.z ~= 0 and dir.x == 0 then
+		left.x = -dir.z
+		right.x = dir.z
+	elseif dir.x ~= 0 and dir.z == 0 then
+		left.z = dir.x
+		right.z = -dir.x
+	end
+	
+	if ctrl then
+		if old_switch == 1 then
+			left_check = false
+		elseif old_switch == 2 then
+			right_check = false
+		end
+		if ctrl.left and left_check then
+			cur = hicarts:check_front_up_down(pos, left, false, railtype)
+			if cur then
+				return cur, 1
+			end
+			left_check = false
+		end
+		if ctrl.right and right_check then
+			cur = hicarts:check_front_up_down(pos, right, false, railtype)
+			if cur then
+				return cur, 2
+			end
+			right_check = true
+		end
+	end
+	
+	-- Normal
+	cur = hicarts:check_front_up_down(pos, dir, true, railtype)
+	if cur then
+		return cur
+	end
+	
+	-- Left, if not already checked
+	if left_check then
+		cur = hicarts:check_front_up_down(pos, left, false, railtype)
+		if cur then
+			return cur
+		end
+	end
+	
+	-- Right, if not already checked
+	if right_check then
+		cur = hicarts:check_front_up_down(pos, right, false, railtype)
+		if cur then
+			return cur
+		end
+	end
+	
+	-- Backwards
+	if not old_switch then
+		cur = hicarts:check_front_up_down(pos, {
+				x = -dir.x,
+				y = dir.y,
+				z = -dir.z
+			}, true, railtype)
+		if cur then
+			return cur
+		end
+	end
+	
+	return {x=0, y=0, z=0}
+end
+
+function hicarts:boost_rail(pos, amount)
+	minetest.get_meta(pos):set_string("cart_acceleration", tostring(amount))
+	for _,obj_ in ipairs(minetest.get_objects_inside_radius(pos, 0.5)) do
+		if not obj_:is_player() and
+				obj_:get_luaentity() and
+				obj_:get_luaentity().name == "carts:cart" then
+			obj_:get_luaentity():on_punch()
+		end
+	end
+end