Function lerp

lerp(a, b, t, dst?): Vec4
Performs linear interpolation on two vectors. Given vectors a and b and interpolation coefficient t, returns a + t * (b - a).
Parameters
- a: Vec4
  Operand vector.
- b: Vec4
  Operand vector.
- t: number
  Interpolation coefficient.
- Optional dst: Vec4
  vector to hold result. If not passed in a new one is created.
Returns Vec4
The linear interpolated result.