/// <summary>
/// Unproject a point from the screen (2D) to a point on plane (3D)
/// </summary>
/// <param name="p">
/// The 2D point.
/// </param>
/// <param name="position">
/// plane position
/// </param>
/// <param name="normal">
/// plane normal
/// </param>
/// <returns>
/// A 3D point.
/// </returns>
public Point3D?UnProject(Point p, Point3D position, Vector3D normal)
{
Ray3D ray = this.GetRay(p);
if (ray == null)
{
return(null);
}
return(ray.PlaneIntersection(position, normal));
}
/// <summary>
/// Un projects a point from the screen (2D) to a point on plane (3D)
/// </summary>
/// <param name="p">
/// The 2D point.
/// </param>
/// <param name="position">
/// A point on the plane .
/// </param>
/// <param name="normal">
/// The plane normal.
/// </param>
/// <returns>
/// A 3D point.
/// </returns>
public Point3D? UnProject(Point p, Point3D position, Vector3D normal)
{
Ray3D ray = this.GetRay(p);
if (ray == null)
{
return null;
}
Point3D i;
return ray.PlaneIntersection(position, normal, out i) ? (Point3D?)i : null;
}
/// <summary>
/// Unproject a point from the screen (2D) to a point on plane (3D)
/// </summary>
/// <param name="viewport">
/// The viewport.
/// </param>
/// <param name="p">
/// The 2D point.
/// </param>
/// <param name="position">
/// plane position
/// </param>
/// <param name="normal">
/// plane normal
/// </param>
/// <returns>
/// A 3D point.
/// </returns>
/// <remarks>
/// Map window coordinates to object coordinates like gluUnProject.
/// </remarks>
public static Point3D?UnProject(Viewport3D viewport, Point p, Point3D position, Vector3D normal)
{
Ray3D ray = GetRay(viewport, p);
if (ray == null)
{
return(null);
}
return(ray.PlaneIntersection(position, normal));
}
/// <summary>
/// Gets the nearest point on the translation axis.
/// </summary>
/// <param name="position">
/// The position (in screen coordinates).
/// </param>
/// <param name="hitPlaneOrigin">
/// The hit plane origin (world coordinate system).
/// </param>
/// <param name="hitPlaneNormal">
/// The hit plane normal (world coordinate system).
/// </param>
/// <returns>
/// The nearest point (world coordinates) or null if no point could be found.
/// </returns>
private Point3D?GetNearestPoint(Point position, Point3D hitPlaneOrigin, Vector3D hitPlaneNormal)
{
var hpp = this.GetHitPlanePoint(position, hitPlaneOrigin, hitPlaneNormal);
if (hpp == null)
{
return(null);
}
var ray = new Ray3D(this.ToWorld(this.Position), this.ToWorld(this.Direction));
return(ray.GetNearest(hpp.Value));
}
/// <summary>
/// Gets the nearest point on the translation axis.
/// </summary>
/// <param name="position">
/// The position (in screen coordinates).
/// </param>
/// <param name="hitPlaneOrigin">
/// The hit plane origin (world coordinate system).
/// </param>
/// <param name="hitPlaneNormal">
/// The hit plane normal (world coordinate system).
/// </param>
/// <returns>
/// The nearest point (world coordinates) or null if no point could be found.
/// </returns>
private Point3D? GetNearestPoint(Point position, Point3D hitPlaneOrigin, Vector3D hitPlaneNormal)
{
var hpp = this.GetHitPlanePoint(position, hitPlaneOrigin, hitPlaneNormal);
if (hpp == null)
{
return null;
}
var ray = new Ray3D(this.ToWorld(this.Position), this.ToWorld(this.Direction));
return ray.GetNearest(hpp.Value);
}
/// <summary>
/// Gets the intersection with the specified ray.
/// </summary>
/// <param name="ray">The ray.</param>
/// <param name="result">The intersection point(s).</param>
/// <returns>The intersection points sorted by distance from the ray origin.</returns>
public bool RayIntersection(Ray3D ray, out Point3D[] result)
{
double cx = this.center.X;
double cy = this.center.Y;
double cz = this.center.Z;
double r = this.radius;
double x1 = ray.Origin.X;
double y1 = ray.Origin.Y;
double z1 = ray.Origin.Z;
double dx = ray.Direction.X;
double dy = ray.Direction.Y;
double dz = ray.Direction.Z;
// Quadratic solving
double a = (dx * dx) + (dy * dy) + (dz * dz);
double b = (2 * dx * (x1 - cx)) + (2 * dy * (y1 - cy)) + (2 * dz * (z1 - cz));
double c = (x1 * x1) + (y1 * y1) + (z1 * z1) + (cx * cx) + (cz * cz) + (cy * cy) - (2 * ((cy * y1) + (cz * z1) + (cx * x1))) - (r * r);
// Discriminant
double q = (b * b) - (4 * a * c);
// We have at least one possible intersection
if (q >= 0)
{
double q2 = Math.Sqrt((b * b) - (4 * a * c));
// First root
double t1 = (-b + q2) / (2 * a);
// Second root
double t2 = (-b - q2) / (2 * a);
if (t1 >= 0 && t2 >= 0 && !t1.Equals(t2))
{
var i1 = new Point3D(x1 + (dx * t1), y1 + (dy * t1), z1 + (dz * t1));
var i2 = new Point3D(x1 + (dx * t2), y1 + (dy * t2), z1 + (dz * t2));
result = t1 < t2 ? new[] { i1, i2 } : new[] { i2, i1 };
return true;
}
if (t1 >= 0)
{
var i1 = new Point3D(x1 + (dx * t1), y1 + (dy * t1), z1 + (dz * t1));
result = new[] { i1 };
return true;
}
if (t2 >= 0)
{
var i2 = new Point3D(x1 + (dx * t2), y1 + (dy * t2), z1 + (dz * t2));
result = new[] { i2 };
return true;
}
}
result = null;
return false;
}
/// <summary>
/// Updates the cursor position.
/// </summary>
/// <param name="pt">The position of the cursor (in viewport coordinates).</param>
private void UpdateCursorPosition(Point pt)
{
this.CursorOnElementPosition = this.FindNearestPoint(pt);
this.CursorPosition = this.Viewport.UnProject(pt);
// Calculate the cursor ray
Point3D cursorNearPlanePoint;
Point3D cursorFarPlanePoint;
var ok = this.Viewport.Point2DtoPoint3D(pt, out cursorNearPlanePoint, out cursorFarPlanePoint);
if (ok)
{
var ray = new Ray3D(cursorFarPlanePoint, cursorNearPlanePoint);
this.CursorRay = ray;
}
else
{
this.CursorOnConstructionPlanePosition = null;
this.CursorRay = null;
}
// Calculate the intersection between the construction plane and the cursor ray
if (this.CursorRay != null)
{
this.CursorOnConstructionPlanePosition = this.ConstructionPlane.LineIntersection(
this.CursorRay.Origin,
this.CursorRay.Origin + this.CursorRay.Direction);
}
else
{
this.CursorOnConstructionPlanePosition = null;
}
// TODO: remove this code when the CurrentPosition property is removed
#pragma warning disable 618
if (this.CursorOnElementPosition.HasValue)
{
this.CurrentPosition = this.CursorOnElementPosition.Value;
}
else
{
if (this.CursorPosition.HasValue)
{
this.CurrentPosition = this.CursorPosition.Value;
}
}
#pragma warning restore 618
}
/// <summary>
/// Gets the intersection with the specified ray.
/// </summary>
/// <param name="ray">
/// The ray.
/// </param>
/// <param name="result">
/// The result.
/// </param>
/// <returns>
/// True if intersections were found.
/// </returns>
public bool RayIntersection(Ray3D ray, out Point3D[] result)
{
throw new NotImplementedException();
// http://www.devmaster.net/wiki/Ray-sphere_intersection
}
/// <summary>
/// Gets the intersection with the specified ray.
/// </summary>
/// <param name="ray">
/// The ray.
/// </param>
/// <param name="result">
/// The result.
/// </param>
/// <returns>
/// True if intersections were found.
/// </returns>
public bool RayIntersection(Ray3D ray, out Point3D[] result)
{
throw new NotImplementedException();
// http://www.devmaster.net/wiki/Ray-sphere_intersection
}
/// <summary>
/// Gets the intersection with the specified ray.
/// </summary>
/// <param name="ray">The ray.</param>
/// <param name="result">The intersection point(s).</param>
/// <returns>The intersection points sorted by distance from the ray origin.</returns>
public bool RayIntersection(Ray3D ray, out Point3D[] result)
{
double cx = this.center.X;
double cy = this.center.Y;
double cz = this.center.Z;
double r = this.radius;
double x1 = ray.Origin.X;
double y1 = ray.Origin.Y;
double z1 = ray.Origin.Z;
double dx = ray.Direction.X;
double dy = ray.Direction.Y;
double dz = ray.Direction.Z;
// Quadratic solving
double a = (dx * dx) + (dy * dy) + (dz * dz);
double b = (2 * dx * (x1 - cx)) + (2 * dy * (y1 - cy)) + (2 * dz * (z1 - cz));
double c = (x1 * x1) + (y1 * y1) + (z1 * z1) + (cx * cx) + (cz * cz) + (cy * cy) - (2 * ((cy * y1) + (cz * z1) + (cx * x1))) - (r * r);
// Discriminant
double q = (b * b) - (4 * a * c);
// We have at least one possible intersection
if (q >= 0)
{
double q2 = Math.Sqrt((b * b) - (4 * a * c));
// First root
double t1 = (-b + q2) / (2 * a);
// Second root
double t2 = (-b - q2) / (2 * a);
if (t1 >= 0 && t2 >= 0 && !t1.Equals(t2))
{
var i1 = new Point3D(x1 + (dx * t1), y1 + (dy * t1), z1 + (dz * t1));
var i2 = new Point3D(x1 + (dx * t2), y1 + (dy * t2), z1 + (dz * t2));
result = t1 < t2 ? new[] { i1, i2 } : new[] { i2, i1 };
return(true);
}
if (t1 >= 0)
{
var i1 = new Point3D(x1 + (dx * t1), y1 + (dy * t1), z1 + (dz * t1));
result = new[] { i1 };
return(true);
}
if (t2 >= 0)
{
var i2 = new Point3D(x1 + (dx * t2), y1 + (dy * t2), z1 + (dz * t2));
result = new[] { i2 };
return(true);
}
}
result = null;
return(false);
}
