The metatable for a 4d vector class, use the new function to actually create an object.

We also inherit all the functions from tardis.array

v4 = v4:add(v4b)
v4 = v4:add(v4b,r)

Add v4b to v4.

If r is provided then the result is written into r and returned otherwise v4 is modified and returned.

value = a:distance(b)

Returns the length of the vector between a and b.

value = v4:dot(v4b)

Return the dot product of these two vectors.

v4 = v4:identity()

Set this v4 to all zeros.

value = v4:len()

Returns the length of this vector.

value = v4:lenlen()

Returns the length of this vector, squared, this is often all you need for comparisons so lets us skip the sqrt.

v4 = v4:mul(v4b)
v4 = v4:mul(v4b,r)

Multiply v4 by v4b.

If r is provided then the result is written into r and returned otherwise v4 is modified and returned.

v4 = tardis.v4.new()

Create a new v4 and optionally set it to the given values, v4 methods usually return the input v4 for easy function chaining.

v4 = v4:normalize()
v4 = v4:normalize(r)

Adjust the length of this vector to 1.

An input length of 0 will remain at 0.

If r is provided then the result is written into r and returned otherwise v4 is modified and returned.

v4 = v4:oo()
v4 = v4:oo(r)

One Over value. Build the reciprocal of all elements.

If r is provided then the result is written into r and returned otherwise v4 is modified and returned.

v4 = v4:scale(s)
v4 = v4:scale(s,r)

Scale this v4 by s.

If r is provided then the result is written into r and returned otherwise v4 is modified and returned.

v4 = v4:sub(v4b)
v4 = v4:sub(v4b,r)

Subtract v4b from v4.

If r is provided then the result is written into r and returned otherwise v4 is modified and returned.

v3 = v4:to_v3()
v3 = v4:to_v3(r)

scale [4] to 1 then throw it away so we have a v3 xyz

If r is provided then the result is written into r and returned otherwise a new v3 is created and returned.