@Test
public void testLerp() {

  final ColorRGBA clr1 = new ColorRGBA(8, 3, -2, 2);
  final ColorRGBA clr2 = new ColorRGBA(2, 1, 0, -2);
  assertEquals(new ColorRGBA(5, 2, -1, 0), clr1.lerp(clr2, 0.5f, null));
  assertEquals(new ColorRGBA(5, 2, -1, 0), clr1.lerp(clr2, 0.5f, new ColorRGBA()));
  assertEquals(new ColorRGBA(5, 2, -1, 0), ColorRGBA.lerp(clr1, clr2, 0.5f, null));
  assertEquals(new ColorRGBA(5, 2, -1, 0), ColorRGBA.lerp(clr1, clr2, 0.5f, new ColorRGBA()));
  clr1.set(14, 5, 4, 2);
  clr1.lerpLocal(clr2, 0.25f);
  assertEquals(new ColorRGBA(11, 4, 3, 1), clr1);
  clr1.set(15, 7, 6, 8);
  final ColorRGBA clr3 = new ColorRGBA(-1, -1, -1, -1);
  clr3.lerpLocal(clr1, clr2, 0.5f);
  assertEquals(new ColorRGBA(8.5f, 4.0f, 3.0f, 3.0f), clr3);
  // coverage
  assertEquals(clr1.lerp(clr1, .25f, null), clr1);
  assertEquals(clr2.lerpLocal(clr2, .25f), clr2);
  assertEquals(clr2.lerpLocal(clr2, clr2, .25f), clr2);
  assertEquals(ColorRGBA.lerp(clr1, clr1, .25f, null), clr1);
}