Vec2 { public double distanceTo(Vec2 vector) { if (vector == null) { throw new IllegalArgumentException( Logger.logMessage(Logger.ERROR, "Vec2", "distanceTo", "missingVector")); } return Math.sqrt(this.distanceToSquared(vector)); } Vec2();  Vec2(double x, double y);  Vec2(Vec2 vector); @Override boolean equals(Object o); @Override int hashCode(); @Override String toString(); float[] toArray(float[] result, int offset); double magnitude(); double magnitudeSquared(); double distanceTo(Vec2 vector); double distanceToSquared(Vec2 vector); Vec2 set(double x, double y); Vec2 set(Vec2 vector); Vec2 swap(Vec2 vector); Vec2 add(Vec2 vector); Vec2 subtract(Vec2 vector); Vec2 multiply(double scalar); Vec2 multiplyByMatrix(Matrix3 matrix); Vec2 divide(double divisor); Vec2 negate(); Vec2 normalize(); double dot(Vec2 vector); Vec2 mix(Vec2 vector, double weight); public double x; public double y; }
@Test public void testDistanceTo() throws Exception { Vec2 u = new Vec2(3, 4); Vec2 v = new Vec2(-3, -4); double distanceTo = u.distanceTo(v); assertEquals("3,4,5 hypotenuse length doubled", 10d, distanceTo, Double.MIN_VALUE); }
@Test(expected = IllegalArgumentException.class) public void testDistanceTo_NullArgument() throws Exception { Vec2 u = new Vec2(); double distanceTo = u.distanceTo(null); fail("Expected an IllegalArgumentException to be thrown."); }