using System;
using Microsoft.Xna.Framework;
namespace WaveRace360
{
public class Camera3D
{
// ------------------------------------------------------------------------
// Private Members
//
private Vector3 m_forward; // The up vector
private Vector3 m_right; // The right vector
private Vector3 m_up; // The up vector
private Vector3 m_pos; // The camera position
private float m_fieldOfView; // The field of view
private float m_aspectRatio; // The aspect ration
private float m_nearPlane; // The near plane
private float m_farPlane; // The far plane
private BoundingFrustum m_frustum; // The bounding frustum
private Matrix m_viewMatrix; // The view matrix
private Matrix m_projMatrix; // The projection matrix
private Matrix m_viewProjMatrix; // The combined view proj matrix
// ------------------------------------------------------------------------
// Public Members
//
public Vector3 Forward { get { return m_forward; } }
public Vector3 Right { get { return m_right; } }
public Vector3 Up { get { return m_up; } }
public Vector3 Pos { get { return m_pos; } }
public float FieldOfView { get { return m_fieldOfView; } }
public float AspectRatio { get { return m_aspectRatio; } }
public float NearPlane { get { return m_nearPlane; } }
public float FarPlane { get { return m_farPlane; } }
public BoundingFrustum Frustum { get { return m_frustum; } }
public Matrix ViewMatrix { get { return m_viewMatrix; } }
public Matrix ProjMatrix { get { return m_projMatrix; } }
public Matrix ViewProjMatrix { get { return m_viewProjMatrix; } }
// ------------------------------------------------------------------------
// Constructor
//
public Camera3D()
{
m_viewMatrix = Matrix.Identity;
m_projMatrix = Matrix.Identity;
m_frustum = new BoundingFrustum(Matrix.Identity);
SetProjection(MathHelper.PiOver4, 0.75f, 1.0f, 10000.0f);
SetView(Vector3.Forward, Vector3.Right, Vector3.Up);
}
// ------------------------------------------------------------------------
// Set the projection of the camera
//
public void SetProjection(float a_fieldOfView, float a_aspectRatio, float a_nearPlane, float a_farPlane)
{
m_fieldOfView = a_fieldOfView;
m_aspectRatio = a_aspectRatio;
m_nearPlane = a_nearPlane;
m_farPlane = a_farPlane;
UpdateMatrix();
}
// ------------------------------------------------------------------------
// Set the view
//
public void SetView(Vector3 a_forward, Vector3 a_right, Vector3 a_up)
{
m_forward = a_forward;
m_right = a_right;
m_up = a_up;
UpdateMatrix();
}
// ------------------------------------------------------------------------
// Set the view and position
//
public void SetView(Vector3 a_pos, Vector3 a_forward, Vector3 a_right, Vector3 a_up)
{
m_pos = a_pos;
m_forward = a_forward;
m_right = a_right;
m_up = a_up;
UpdateMatrix();
}
// ------------------------------------------------------------------------
// Set the position
//
public void SetPosition(Vector3 a_pos, Vector3 a_forward, Vector3 a_right, Vector3 a_up)
{
m_pos = a_pos;
UpdateMatrix();
}
// ------------------------------------------------------------------------
// Set the view using look-at vectors
//
public void SetLookAt(Vector3 a_eye, Vector3 a_at, Vector3 a_up)
{
m_pos = a_eye;
m_up = a_up;
m_forward = a_at - a_eye;
m_forward.Normalize();
m_right = Vector3.Cross(m_forward, m_up);
m_right.Normalize();
UpdateMatrix();
}
// ------------------------------------------------------------------------
// Update the projection and view matrices
//
private void UpdateMatrix()
{
// Calculate the projection matrix
m_projMatrix = Matrix.CreatePerspectiveFieldOfView(m_fieldOfView, m_aspectRatio, m_nearPlane, m_farPlane);
// Calculate the view matrix
m_viewMatrix = Matrix.CreateLookAt(m_pos, m_pos + m_forward, m_up);
// Calculate the bounding frustum
m_viewProjMatrix = Matrix.Multiply(m_viewMatrix, m_projMatrix);
m_frustum.Matrix = m_viewProjMatrix;
}
//
// ------------------------------------------------------------------------
}
}
// -- EOF
