/// <summary>
/// Retrieves the current camera vectors which represent the current forward, right and up directions
/// for the camera.
/// </summary>
/// <returns></returns>
public CameraVectors GetCameraVectors()
{
if (_validCameraVectors)
{
return(_cameraVectors);
}
_cameraVectors = CameraVectors.FromYawPitchRoll(_yaw, _pitch, 0F);
_validCameraVectors = true;
return(_cameraVectors);
}
/// <summary>
/// Retrieves the view matrix for the current class instance.
/// </summary>
/// <returns>The view matrix.</returns>
public Matrix GetViewMatrix()
{
if (_validViewMatrix && _validCameraVectors)
{
return(_viewMatrix);
}
_cameraVectors = GetCameraVectors();
_viewMatrix = Matrix.LookAtRH(_position, _position + _cameraVectors._forwardVector, Vector3.Up);
_validViewMatrix = true;
return(_viewMatrix);
}
/// <summary>
/// Calculates the camera movement vectors from
/// </summary>
/// <param name="yawDegrees">The direction that moves the camera left and right.</param>
/// <param name="pitchDegrees">The direction that moves the camera up and down.</param>
/// <param name="rollDegrees">Self explanatory.</param>
public static CameraVectors FromYawPitchRoll(float yawRadians, float pitchRadians, float rollRadians)
{
CameraVectors cameraVectors = new CameraVectors();
Matrix.RotationYawPitchRoll(yawRadians, pitchRadians, rollRadians, out Matrix result);
cameraVectors._forwardVector = (Vector3)Vector3.Transform(Vector3.ForwardRH, result);
cameraVectors._forwardVector.Normalize();
cameraVectors._leftVector = Vector3.Cross(Vector3.Up, cameraVectors._forwardVector);
cameraVectors._leftVector.Normalize();
cameraVectors._upVector = Vector3.Cross(cameraVectors._forwardVector, cameraVectors._leftVector);
cameraVectors._upVector.Normalize();
return(cameraVectors);
}