better camera rotation with lookAt + rotation of view direction

hw3d/Camera.cpp

@@ -11,8 +11,19 @@ Camera::Camera() noexcept
 
 DirectX::XMMATRIX Camera::GetMatrix() const noexcept
 {
-	return dx::XMMatrixTranslation( -pos.x,-pos.y,-pos.z ) *
-		dx::XMMatrixRotationRollPitchYaw( -pitch,-yaw,0.0f );
+	using namespace dx;
+
+	const dx::XMVECTOR forwardBaseVector = XMVectorSet( 0.0f,0.0f,1.0f,0.0f );
+	// apply the camera rotations to a base vector
+	const auto lookVector = XMVector3Transform( forwardBaseVector,
+		XMMatrixRotationRollPitchYaw( pitch,yaw,0.0f )
+	);
+	// generate camera transform (applied to all objects to arrange them relative
+	// to camera position/orientation in world) from cam position and direction
+	// camera "top" always faces towards +Y (cannot do a barrel roll)
+	const auto camPosition = XMLoadFloat3( &pos );
+	const auto camTarget = camPosition + lookVector;
+	return XMMatrixLookAtLH( camPosition,camTarget,XMVectorSet( 0.0f,1.0f,0.0f,0.0f ) );
 }
 
 void Camera::SpawnControlWindow() noexcept