private static Point3D?CastRay_Line(out double clickDistanceSquared, Point3D point, Vector3D direction, RayHitTestParameters mouseDownClickRay, RayHitTestParameters mouseDownCenterRay, RayHitTestParameters currentClickRay)
{
// This is the offset along the drag line from the center to mouse down click
Vector3D offset;
Point3D?point1, point2, point3, point4;
if (Math3D.GetClosestPoints_Line_Line(out point1, out point2, point, direction, mouseDownClickRay.Origin, mouseDownClickRay.Direction) &&
Math3D.GetClosestPoints_Line_Line(out point3, out point4, point, direction, mouseDownCenterRay.Origin, mouseDownCenterRay.Direction))
{
offset = point3.Value - point1.Value; // clickpoint on drag line minus centerpoint on drag line
}
else
{
// The click ray is parallel to the drag axis. This should be extremely rare
offset = new Vector3D(0, 0, 0);
}
// Now that the offset is known, project the current click ray onto the drag line
if (Math3D.GetClosestPoints_Line_Line(out point1, out point2, point, direction, currentClickRay.Origin, currentClickRay.Direction))
{
clickDistanceSquared = (point2.Value - point1.Value).LengthSquared;
return(point1.Value + offset);
}
else
{
clickDistanceSquared = 0;
return(null);
}
}
private static Point3D?CastRay_LinesCircles(IEnumerable <RayHitTestParameters> lines, IEnumerable <CircleDefinition> circles, RayHitTestParameters ray)
{
Point3D?retVal = null;
double distance = double.MaxValue;
if (lines != null)
{
// Cast onto each line, and return the point that's closest to the ray's origin
foreach (RayHitTestParameters line in lines)
{
Point3D?point1, point2;
if (Math3D.GetClosestPoints_Line_Line(out point1, out point2, line.Origin, line.Direction, ray.Origin, ray.Direction))
{
double localDistance = (point2.Value - point1.Value).LengthSquared;
if (retVal == null || localDistance < distance)
{
retVal = point1.Value;
distance = localDistance;
}
}
}
}
if (circles != null)
{
// Cast onto each circle, and return the point that's closest to the ray's origin
foreach (CircleDefinition circle in circles)
{
Point3D[] points1, points2;
if (Math3D.GetClosestPoints_Circle_Line(out points1, out points2, circle.Plane, circle.Center, circle.Radius, ray.Origin, ray.Direction, Math3D.RayCastReturn.ClosestToRay))
{
double localDistance = (points2[0] - points1[0]).LengthSquared;
if (retVal == null || localDistance < distance)
{
retVal = points1[0];
distance = localDistance;
}
}
}
}
return(retVal);
}
/// <summary>
/// This overload is a straight ray cast, nothing extra
/// </summary>
public Point3D?CastRay(RayHitTestParameters ray)
{
Point3D?retVal = null;
switch (_shape)
{
case ShapeType.Line:
#region Line
Point3D?point1, point2;
if (Math3D.GetClosestPoints_Line_Line(out point1, out point2, _point, _direction, ray.Origin, ray.Direction))
{
retVal = point1.Value;
}
#endregion
break;
case ShapeType.Lines:
#region Lines
retVal = CastRay_LinesCircles(_lines, null, ray);
#endregion
break;
case ShapeType.Plane:
#region Plane
retVal = Math3D.GetIntersection_Plane_Line(_plane, ray.Origin, ray.Direction);
#endregion
break;
case ShapeType.Circle:
#region Circle
Point3D[] nearestCirclePoints, nearestLinePoints;
if (Math3D.GetClosestPoints_Circle_Line(out nearestCirclePoints, out nearestLinePoints, _plane, _point, _radius, ray.Origin, ray.Direction, Math3D.RayCastReturn.ClosestToRay))
{
retVal = nearestCirclePoints[0];
}
#endregion
break;
case ShapeType.Circles:
#region Circles
retVal = CastRay_LinesCircles(null, _circles, ray);
#endregion
break;
case ShapeType.LinesCircles:
#region LinesCircles
retVal = CastRay_LinesCircles(_lines, _circles, ray);
#endregion
break;
case ShapeType.Cylinder:
#region Cylinder
Point3D[] nearestCylinderPoints, nearestLinePoints2;
if (Math3D.GetClosestPoints_Cylinder_Line(out nearestCylinderPoints, out nearestLinePoints2, _point, _direction, _radius, ray.Origin, ray.Direction, Math3D.RayCastReturn.ClosestToRay))
{
retVal = nearestCylinderPoints[0];
}
#endregion
break;
case ShapeType.Sphere:
#region Sphere
Point3D[] nearestSpherePoints, nearestLinePoints3;
Math3D.GetClosestPoints_Sphere_Line(out nearestSpherePoints, out nearestLinePoints3, _point, _radius, ray.Origin, ray.Direction, Math3D.RayCastReturn.ClosestToRay);
{
retVal = nearestSpherePoints[0];
}
#endregion
break;
case ShapeType.Mesh:
throw new ApplicationException("finish this");
case ShapeType.None:
retVal = null;
break;
default:
throw new ApplicationException("Unknown ShapeType: " + _shape.ToString());
}
return(retVal);
}
