minetest/builtin/vector.lua
2013-07-07 02:29:09 -04:00

142 lines
2.4 KiB
Lua

vector = {}
function vector.new(a, b, c)
v = {x=0, y=0, z=0}
if type(a) == "table" then
v = {x=a.x, y=a.y, z=a.z}
elseif a and b and c then
v = {x=a, y=b, z=c}
end
setmetatable(v, {
__add = vector.add,
__sub = vector.subtract,
__mul = vector.multiply,
__div = vector.divide,
__umn = function(v) return vector.multiply(v, -1) end,
__len = vector.length,
__eq = vector.equals,
})
return v
end
function vector.equals(a, b)
return a.x == b.x and
a.y == b.y and
a.z == b.z
end
function vector.length(v)
return math.hypot(v.x, math.hypot(v.y, v.z))
end
function vector.normalize(v)
local len = vector.length(v)
if len == 0 then
return vector.new()
else
return vector.divide(v, len)
end
end
function vector.round(v)
return {
x = math.floor(v.x + 0.5),
y = math.floor(v.y + 0.5),
z = math.floor(v.z + 0.5)
}
end
function vector.distance(a, b)
local x = a.x - b.x
local y = a.y - b.y
local z = a.z - b.z
return math.hypot(x, math.hypot(y, z))
end
function vector.direction(pos1, pos2)
local x_raw = pos2.x - pos1.x
local y_raw = pos2.y - pos1.y
local z_raw = pos2.z - pos1.z
local x_abs = math.abs(x_raw)
local y_abs = math.abs(y_raw)
local z_abs = math.abs(z_raw)
if x_abs >= y_abs and
x_abs >= z_abs then
y_raw = y_raw * (1 / x_abs)
z_raw = z_raw * (1 / x_abs)
x_raw = x_raw / x_abs
end
if y_abs >= x_abs and
y_abs >= z_abs then
x_raw = x_raw * (1 / y_abs)
z_raw = z_raw * (1 / y_abs)
y_raw = y_raw / y_abs
end
if z_abs >= y_abs and
z_abs >= x_abs then
x_raw = x_raw * (1 / z_abs)
y_raw = y_raw * (1 / z_abs)
z_raw = z_raw / z_abs
end
return {x=x_raw, y=y_raw, z=z_raw}
end
function vector.add(a, b)
if type(b) == "table" then
return vector.new(
a.x + b.x,
a.y + b.y,
a.z + b.z)
else
return vector.new(
a.x + b,
a.y + b,
a.z + b)
end
end
function vector.subtract(a, b)
if type(b) == "table" then
return vector.new(
a.x - b.x,
a.y - b.y,
a.z - b.z)
else
return vector.new(
a.x - b,
a.y - b,
a.z - b)
end
end
function vector.multiply(a, b)
if type(b) == "table" then
return vector.new(
a.x * b.x,
a.y * b.y,
a.z * b.z)
else
return vector.new(
a.x * b,
a.y * b,
a.z * b)
end
end
function vector.divide(a, b)
if type(b) == "table" then
return vector.new(
a.x / b.x,
a.y / b.y,
a.z / b.z)
else
return vector.new(
a.x / b,
a.y / b,
a.z / b)
end
end