Matrix4 ArcBallCameraController::ViewMatrix(Matrix4 &viewMatrix_)
{
if (m_bRecomputeViewMatrix == true)
{
m_bRecomputeViewMatrix = false;
viewMatrix_.LookAt(m_Target - (Direction() * m_fDistance), m_Target, Up());
}
return viewMatrix_;
}
/// <summary>
/// Sets up a quaternion & position from vector camera components
/// and oriented the camera up
/// </summary>
/// <param name="eye">The camera position</param>
/// <param name="lookAt">The camera's look-at point</param>
/// <param name="up"></param>
void ArcBallCameraController::SetCamera(Vector3F position, Vector3F target, Vector3F up)
{
m_bRecomputeViewMatrix = true;
//Create a look at matrix, to simplify matters a bit
Matrix4 temp;
temp.LookAt(position, target, up);
//invert the matrix, since we're determining the
//orientation from the rotation matrix in RH coords
temp.Invert();
//set the position
m_Target = target;
//set distance
m_fDistance = (target - position).Length();
//create the new aspect from the look-at matrix
m_ArcBallOrientation.FromMatrix(temp);
//When setting a new eye-view direction
//in one of the gamble-locked modes, the yaw and
//pitch gimble must be calculated.
//first, get the direction projected on the x/z plne
Vector3F dir = Direction();
dir.y = 0.0f;
if (dir.Length() == 0.0f)
{
dir = Vector3F::Forward();
}
dir.Normalize();
//find the yaw of the direction on the x/z plane
//and use the sign of the x-component since we have 360 degrees
//of freedom
m_fArcBallYaw = (acosf(-dir.z) * Sign(dir.x));
//Get the pitch from the angle formed by the Up vector and the
//the forward direction, then subtracting Pi / 2, since
//we pitch is zero at Forward, not Up.
m_fArcBallPitch = -(acosf(Vector3F::Dot(Vector3F::Up(), Direction())) - MATH_PI_DIV_2);
}