Dimension RayIntersectionWithPlane (const SRay &Ray, const SRay &PlaneNormal)
// RayIntersectionWithPlane
//
// Returns the distance along the ray at which it intersects the given plane
// If the two do not intersect, we return INFINITY
//
// Source: Foley/vanDam, p.703
{
// Get the coefficients for the plane equation
Dimension A, B, C, D;
PlaneEq(PlaneNormal, &A, &B, &C, &D);
// Compute ray deltas
Dimension dX = Ray.vDir.X();
Dimension dY = Ray.vDir.Y();
Dimension dZ = Ray.vDir.Z();
// Compute intersection
Dimension rDenominator = A * dX + B * dY + C * dZ;
if (EqZero(rDenominator))
return INFINITY;
// Done
return -(A * Ray.vOrigin.X() + B * Ray.vOrigin.Y() + C * Ray.vOrigin.Z() + D) / rDenominator;
}
PositionShapePart( const Moo::Colour& col, int axis )
: colour_( col ),
isFree_( false ),
isPlane_( true )
{
Vector3 normal( 0, 0, 0 );
normal[axis] = 1.f;
planeEq_ = PlaneEq( normal, 0 );
}
//TODO: create some general purpose clip plane functionality
PlaneEq currentClipPlane()
{
return PlaneEq(Vector3(0,waterHeight(),0), Vector3(0,1,0));
}
