boost_cart/functions.lua
SmallJoker ced150bc5b Upload
2014-07-22 23:15:43 +02:00

104 lines
1.7 KiB
Lua

function boost_cart:get_sign(z)
if z == 0 then
return 0
else
return z / math.abs(z)
end
end
function boost_cart:velocity_to_dir(v)
if math.abs(v.x) > math.abs(v.z) then
return {x=boost_cart:get_sign(v.x), y=boost_cart:get_sign(v.y), z=0}
else
return {x=0, y=boost_cart:get_sign(v.y), z=boost_cart:get_sign(v.z)}
end
end
function boost_cart:is_rail(pos)
local node = minetest.get_node(pos).name
return minetest.get_item_group(node, "rail") ~= 0
end
function boost_cart:get_rail_direction(pos_, dir_)
local pos = vector.round(pos_)
local dir = vector.new(dir_)
local cur = nil
-- Front
dir.y = 0
cur = vector.add(pos, dir)
if boost_cart:is_rail(cur) then
return dir
end
-- Down
dir.y = -1
cur = vector.add(pos, dir)
if boost_cart:is_rail(cur) then
return dir
end
-- Up
dir.y = 1
cur = vector.add(pos, dir)
if boost_cart:is_rail(cur) then
return dir
end
-- Left, right
dir.y = 0
-- Check left and right
local view, opposite, val
if dir.x == 0 and dir.z ~= 0 then
view = "z"
other = "x"
if dir.z < 0 then
val = {1, -1}
else
val = {-1, 1}
end
elseif dir.z == 0 and dir.x ~= 0 then
view = "x"
other = "z"
if dir.x > 0 then
val = {1, -1}
else
val = {-1, 1}
end
else
return {x=0, y=0, z=0}
end
dir[view] = 0
dir[other] = val[1]
cur = vector.add(pos, dir)
if boost_cart:is_rail(cur) then
return dir
end
-- Down
dir.y = -1
cur = vector.add(pos, dir)
if boost_cart:is_rail(cur) then
return dir
end
dir.y = 0
dir[other] = val[2]
cur = vector.add(pos, dir)
if boost_cart:is_rail(cur) then
return dir
end
-- Down
dir.y = -1
cur = vector.add(pos, dir)
if boost_cart:is_rail(cur) then
return dir
end
return {x=0, y=0, z=0}
end