code: public void setVec4(String key, float x, float y, float z, float w)
      {
          checkKeyIsUniform(key);
          NativeLight.setVec4(getNative(), key, x, y, z, w);
      }
docs: Set the value for a floating point vector of length 4.
  @param key name of uniform to set.
  @param x new X value
  @param y new Y value
  @param z new Z value
  @param w new W value
  @see #getVec4
  @see #getFloatVec(String)