void Camera::BuildViewMatrix(const Maths::Vector4 &position, const Maths::Vector4 &lookAt, const Maths::Vector4 &up)
{
Vector4 viewDir = lookAt - position;
Vector4 viewSide, viewUp;
// store values
m_up = up;
m_position = position;
m_lookAt = lookAt;
viewDir.Normalize();
viewUp = up - viewDir * up.DotProduct( viewDir );
viewUp.Normalize();
viewSide = viewDir.CrossProduct( viewUp );
// setup inverse rotation matrix
Matrix4 rotation;
rotation.SetRows( viewSide, viewUp, Vector4( -viewDir.X, -viewDir.Y, -viewDir.Z, -viewDir.W ), Vector4( 0.0f, 0.0f, 0.0f, 1.0f ) );
//transform translation
Vector4 invPos;
Matrix4::Transform( rotation, position, invPos );
m_inversePosition = -invPos;
// build view matrix
Matrix4 view;
Matrix4::Multiply( view, rotation, m_viewMatrix );
m_viewMatrix( 0, 3 ) = m_inversePosition.X;
m_viewMatrix( 1, 3 ) = m_inversePosition.Y;
m_viewMatrix( 2, 3 ) = m_inversePosition.Z;
m_viewMatrix( 3, 3 ) = m_inversePosition.W;
m_viewDir = viewDir;
}
void Camera::lookAt(const D3DXVECTOR3 &eye, const D3DXVECTOR3 &target, const D3DXVECTOR3 &up)
{
m_eye = eye;
m_zAxis = target - eye;
D3DXVec3Normalize(&m_zAxis, &m_zAxis);
m_viewDir = m_zAxis;
D3DXVec3Cross(&m_xAxis, &up, &m_zAxis);
D3DXVec3Normalize(&m_xAxis, &m_xAxis);
D3DXVec3Cross(&m_yAxis, &m_zAxis, &m_xAxis);
D3DXVec3Normalize(&m_yAxis, &m_yAxis);
D3DXVec3Normalize(&m_xAxis, &m_xAxis);
D3DXMatrixIdentity(&m_viewMatrix);
m_viewMatrix(0,0) = m_xAxis.x;
m_viewMatrix(1,0) = m_xAxis.y;
m_viewMatrix(2,0) = m_xAxis.z;
m_viewMatrix(3,0) = -D3DXVec3Dot(&m_xAxis, &eye);
m_viewMatrix(0,1) = m_yAxis.x;
m_viewMatrix(1,1) = m_yAxis.y;
m_viewMatrix(2,1) = m_yAxis.z;
m_viewMatrix(3,1) = -D3DXVec3Dot(&m_yAxis, &eye);
m_viewMatrix(0,2) = m_zAxis.x;
m_viewMatrix(1,2) = m_zAxis.y;
m_viewMatrix(2,2) = m_zAxis.z;
m_viewMatrix(3,2) = -D3DXVec3Dot(&m_zAxis, &eye);
// Extract the pitch angle from the view matrix.
m_accumPitchDegrees = D3DXToDegree(-asinf(m_viewMatrix(1,2)));
}
void Camera::updateViewMatrix(bool orthogonalizeAxes)
{
if (orthogonalizeAxes)
{
// Regenerate the camera's local axes to orthogonalize them.
D3DXVec3Normalize(&m_zAxis, &m_zAxis);
D3DXVec3Cross(&m_yAxis, &m_zAxis, &m_xAxis);
D3DXVec3Normalize(&m_yAxis, &m_yAxis);
D3DXVec3Cross(&m_xAxis, &m_yAxis, &m_zAxis);
D3DXVec3Normalize(&m_xAxis, &m_xAxis);
m_viewDir = m_zAxis;
}
// Reconstruct the view matrix.
m_viewMatrix(0,0) = m_xAxis.x;
m_viewMatrix(1,0) = m_xAxis.y;
m_viewMatrix(2,0) = m_xAxis.z;
m_viewMatrix(3,0) = -D3DXVec3Dot(&m_xAxis, &m_eye);
m_viewMatrix(0,1) = m_yAxis.x;
m_viewMatrix(1,1) = m_yAxis.y;
m_viewMatrix(2,1) = m_yAxis.z;
m_viewMatrix(3,1) = -D3DXVec3Dot(&m_yAxis, &m_eye);
m_viewMatrix(0,2) = m_zAxis.x;
m_viewMatrix(1,2) = m_zAxis.y;
m_viewMatrix(2,2) = m_zAxis.z;
m_viewMatrix(3,2) = -D3DXVec3Dot(&m_zAxis, &m_eye);
m_viewMatrix(0,3) = 0.0f;
m_viewMatrix(1,3) = 0.0f;
m_viewMatrix(2,3) = 0.0f;
m_viewMatrix(3,3) = 1.0f;
}
void Camera::setViewMatrix()
{
m_viewMatrix(0,0) = m_u.x(); m_viewMatrix(0,1) = m_v.x(); m_viewMatrix(0,2) = m_n.x(); m_viewMatrix(0,3) = 0.0;
m_viewMatrix(1,0) = m_u.y(); m_viewMatrix(1,1) = m_v.y(); m_viewMatrix(1,2) = m_n.y(); m_viewMatrix(1,3) = 0.0;
m_viewMatrix(2,0) = m_u.z(); m_viewMatrix(2,1) = m_v.z(); m_viewMatrix(2,2) = m_n.z(); m_viewMatrix(2,3) =0.0;
m_viewMatrix(3,0) = m_eye.dot(-m_u); m_viewMatrix(3,1)= m_eye.dot(-m_v); m_viewMatrix(3,2)= m_eye.dot(-m_n); m_viewMatrix(3,3) =1.0;
calculateFrustum();
}
