public void TestCloseMiss()
{
Assert.IsFalse(
Line2Disc2Collider.FindContacts(
new Vector2(-1.0f, 2.1f), Vector2.UnitX, 2.0f
).HasContact
);
}
public void TestLineThroughCenter()
{
LineContacts contacts = Line2Disc2Collider.FindContacts(
new Vector2(-3.0f, 0.0f), Vector2.UnitX, 2.0f
);
Assert.That(
contacts.EntryTime,
Is.EqualTo(1.0f).Within(Specifications.MaximumDeviation).Ulps
);
Assert.That(
contacts.ExitTime,
Is.EqualTo(5.0f).Within(Specifications.MaximumDeviation).Ulps
);
}
public void TestCircleWithAbsolutePosition()
{
Vector2 unitDiagonal = Vector2.Normalize(Vector2.One);
LineContacts contacts = Line2Disc2Collider.FindContacts(
Vector2.Zero, unitDiagonal, unitDiagonal * 5.0f, 2.0f
);
Assert.That(
contacts.EntryTime,
Is.EqualTo(3.0f).Within(Specifications.MaximumDeviation).Ulps
);
Assert.That(
contacts.ExitTime,
Is.EqualTo(7.0f).Within(Specifications.MaximumDeviation).Ulps
);
}
/// <summary>Determines where a ray will hit a disc, if at all</summary>
/// <param name="rayStart">Starting point of the ray</param>
/// <param name="rayDirection">Direction into which the ray extends</param>
/// <param name="discCenter">Center of the disc</param>
/// <param name="discRadius">Radius of the disc</param>
/// <returns>The intersection points between the ray and the box, if any</returns>
public static LineContacts FindContacts(
Vector2 rayStart, Vector2 rayDirection, Vector2 discCenter, float discRadius
)
{
LineContacts contacts = Line2Disc2Collider.FindContacts(
rayStart, rayDirection, discCenter, discRadius
);
// If the line has entered the box before the reference point, this means
// that the ray starts within the box, thus, its first contact occurs immediately
if (!float.IsNaN(contacts.EntryTime))
{
if (contacts.ExitTime < 0.0f) // Entry & exit before the ray's beginning?
{
return(LineContacts.None);
}
else if (contacts.EntryTime < 0.0f) // Only entry before ray's beginning?
{
contacts.EntryTime = 0.0f;
}
}
return(contacts);
}
