module.exports = lerp

/**
 * Performs a linear interpolation between two vec4's
 *
 * @param {vec4} out the receiving vector
 * @param {vec4} a the first operand
 * @param {vec4} b the second operand
 * @param {Number} t interpolation amount between the two inputs
 * @returns {vec4} out
 */
function lerp (out, a, b, t) {
  var ax = a[0],
    ay = a[1],
    az = a[2],
    aw = a[3]
  out[0] = ax + t * (b[0] - ax)
  out[1] = ay + t * (b[1] - ay)
  out[2] = az + t * (b[2] - az)
  out[3] = aw + t * (b[3] - aw)
  return out
}