/// <summary>
/// Determines whether there is an intersection between a <see cref="SharpDX.Plane"/> and a point.
/// </summary>
/// <param name="plane">The plane to test.</param>
/// <param name="point">The point to test.</param>
/// <returns>Whether the two objects intersected.</returns>
private static PlaneIntersectionType PlaneIntersectsPoint(ref PlaneD plane, ref Vector3D point)
{
double distance;
Vector3D.Dot(ref plane.Normal, ref point, out distance);
distance += plane.D;
if (distance > 0f)
{
return(PlaneIntersectionType.Front);
}
if (distance < 0f)
{
return(PlaneIntersectionType.Back);
}
return(PlaneIntersectionType.Intersecting);
}
/// <summary>
/// Determines whether there is an intersection between a <see cref="SharpDX.Plane"/> and a point.
/// </summary>
/// <param name="plane">The plane to test.</param>
/// <param name="point">The point to test.</param>
/// <returns>Whether the two objects intersected.</returns>
private static PlaneIntersectionType PlaneIntersectsPoint(ref PlaneD plane, ref Vector3D point)
{
double distance;
Vector3D.Dot(ref plane.Normal, ref point, out distance);
distance += plane.D;
if (distance > 0f)
return PlaneIntersectionType.Front;
if (distance < 0f)
return PlaneIntersectionType.Back;
return PlaneIntersectionType.Intersecting;
}
private static void GetPlanesFromMatrix(ref MatrixD matrix, out PlaneD near, out PlaneD far, out PlaneD left, out PlaneD right, out PlaneD top, out PlaneD bottom)
{
//http://www.chadvernon.com/blog/resources/directx9/frustum-culling/
// Left plane
left.Normal.X = matrix.M14 + matrix.M11;
left.Normal.Y = matrix.M24 + matrix.M21;
left.Normal.Z = matrix.M34 + matrix.M31;
left.D = matrix.M44 + matrix.M41;
left.Normalize();
// Right plane
right.Normal.X = matrix.M14 - matrix.M11;
right.Normal.Y = matrix.M24 - matrix.M21;
right.Normal.Z = matrix.M34 - matrix.M31;
right.D = matrix.M44 - matrix.M41;
right.Normalize();
// Top plane
top.Normal.X = matrix.M14 - matrix.M12;
top.Normal.Y = matrix.M24 - matrix.M22;
top.Normal.Z = matrix.M34 - matrix.M32;
top.D = matrix.M44 - matrix.M42;
top.Normalize();
// Bottom plane
bottom.Normal.X = matrix.M14 + matrix.M12;
bottom.Normal.Y = matrix.M24 + matrix.M22;
bottom.Normal.Z = matrix.M34 + matrix.M32;
bottom.D = matrix.M44 + matrix.M42;
bottom.Normalize();
// Near plane
near.Normal.X = matrix.M13;
near.Normal.Y = matrix.M23;
near.Normal.Z = matrix.M33;
near.D = matrix.M43;
near.Normalize();
// Far plane
far.Normal.X = matrix.M14 - matrix.M13;
far.Normal.Y = matrix.M24 - matrix.M23;
far.Normal.Z = matrix.M34 - matrix.M33;
far.D = matrix.M44 - matrix.M43;
far.Normalize();
}