/// <summary>
/// Intersection test with <see cref="Sphere"/>.
/// </summary>
/// <param name="sphere">Sphere to test.</param>
/// <returns>True if the sphere intersects this volume, and false otherwise.</returns>
public bool Intersects(Sphere sphere)
{
for (int i = 0; i < planes.Count; i++)
{
Plane plane = planes[i];
// Test which side of the plane the sphere is
float d = plane.GetDistance(sphere.Center);
// Negate d if planes point inwards
if (outside == PlaneSide.Negative)
{
d = -d;
}
if ((d - sphere.Radius) > 0)
{
return(false);
}
}
// assume intersecting
return(true);
}
protected bool CalculateForPointLight(Plane plane, Vector3[] vertices, out Vector2[] texCoors, out ColorEx[] colors)
{
texCoors = new Vector2[vertices.Length];
colors = new ColorEx[vertices.Length];
Vector3 lightPos, faceLightPos;
lightPos = this.DerivedPosition;
float dist = plane.GetDistance(lightPos);
if (MathUtil.Abs(dist) < range)
{
// light is visible
//light pos on face
faceLightPos = lightPos - plane.Normal * dist;
Vector3 verAxis = plane.Normal.Perpendicular();
Vector3 horAxis = verAxis.Cross(plane.Normal);
Plane verPlane = new Plane(verAxis, faceLightPos);
Plane horPlane = new Plane(horAxis, faceLightPos);
float lightRadiusSqr = range * range;
float relRadiusSqr = lightRadiusSqr - dist * dist;
float relRadius = MathUtil.Sqrt(relRadiusSqr);
float scale = 0.5f / relRadius;
float brightness = relRadiusSqr / lightRadiusSqr;
ColorEx lightCol = new ColorEx(brightness * textureColor.a,
textureColor.r, textureColor.g, textureColor.b);
for (int i = 0; i < vertices.Length; i++)
{
texCoors[i].x = horPlane.GetDistance(vertices[i]) * scale + 0.5f;
texCoors[i].y = verPlane.GetDistance(vertices[i]) * scale + 0.5f;
colors[i] = lightCol;
}
return true;
}
return false;
}
