|
//---------------------------------------------------------------------------
//
// <copyright file=ProjectionCamera.cs company=Microsoft>
// Copyright (C) Microsoft Corporation. All rights reserved.
// </copyright>
//
//---------------------------------------------------------------------------
using System;
namespace System.Windows.Media.Media3D
{
/// <summary>
/// The ProjectionCamera is an abstract base class from cameras
/// constructed from well-understand parameers such as Position,
/// LookAtPoint, and Up.
/// </summary>
public abstract partial class ProjectionCamera : Camera
{
//------------------------------------------------------
//
// Constructors
//
//------------------------------------------------------
/// <summary>
/// Prevent 3rd parties from extending this abstract base class.
/// </summary>
internal ProjectionCamera()
{
}
//------------------------------------------------------
//
// Public Methods
//
//------------------------------------------------------
//------------------------------------------------------
//
// Public Properties
//
//------------------------------------------------------
//------------------------------------------------------
//
// Public Events
//
//------------------------------------------------------
//------------------------------------------------------
//
// Internal Methods
//
//------------------------------------------------------
#region Internal Methods
internal override Matrix3D GetViewMatrix()
{
Point3D position = Position;
Vector3D lookDirection = LookDirection;
Vector3D upDirection = UpDirection;
return CreateViewMatrix(Transform, ref position, ref lookDirection, ref upDirection);
}
// Transfrom that moves the world to a camera coordinate system
// where the camera is at the origin looking down the negative z
// axis and y is up.
//
// NOTE: We consider camera.Transform to be part of the view matrix.
//
internal static Matrix3D CreateViewMatrix(Transform3D transform, ref Point3D position, ref Vector3D lookDirection, ref Vector3D upDirection)
{
Vector3D zaxis = -lookDirection;
zaxis.Normalize();
Vector3D xaxis = Vector3D.CrossProduct(upDirection, zaxis);
xaxis.Normalize();
Vector3D yaxis = Vector3D.CrossProduct(zaxis, xaxis);
Vector3D positionVec = (Vector3D) position;
double cx = -Vector3D.DotProduct(xaxis, positionVec);
double cy = -Vector3D.DotProduct(yaxis, positionVec);
double cz = -Vector3D.DotProduct(zaxis, positionVec);
Matrix3D viewMatrix = new Matrix3D(
xaxis.X, yaxis.X, zaxis.X, 0,
xaxis.Y, yaxis.Y, zaxis.Y, 0,
xaxis.Z, yaxis.Z, zaxis.Z, 0,
cx, cy, cz, 1);
PrependInverseTransform(transform, ref viewMatrix);
return viewMatrix;
}
#endregion Internal Methods
//------------------------------------------------------
//
// Private Fields
//
//------------------------------------------------------
}
}
|