void Update()
{
if (Input.GetMouseButton(1))
{
// If the mouse is pointing to UI do nothing.
if (!EventSystem.current.IsPointerOverGameObject())
{
if (_dragState == CameraDragState.Idle)
{
_dragState = CameraDragState.Begin;
_dragAction = CameraDragAction.Tilt;
}
}
}
else
{
if (_dragAction == CameraDragAction.Tilt)
{
if (_dragState == CameraDragState.Move)
{
_dragState = CameraDragState.End;
}
}
}
if (Input.GetMouseButton(2))
{
// If the mouse is pointing to UI do nothing.
if (!EventSystem.current.IsPointerOverGameObject())
{
if (_dragState == CameraDragState.Idle)
{
_dragState = CameraDragState.Begin;
_dragAction = CameraDragAction.Pan;
}
}
}
else
{
if (_dragAction == CameraDragAction.Pan)
{
if (_dragState == CameraDragState.Move)
{
_dragState = CameraDragState.End;
}
}
}
// Process wheel input and camera zoom.
if (_dragState == CameraDragState.Idle)
{
float wheelDelta = Input.mouseScrollDelta.y;
if (wheelDelta > 0 || wheelDelta < 0)
{
// Zoom is done in the direction of the mouse.
Ray pickRay = _camera.ScreenPointToRay(Input.mousePosition);
var target = ProjectRayToGround(pickRay);
var moveVector = (target - _camera.transform.position);
if ((moveVector.magnitude > 5 && wheelDelta > 0) || (moveVector.magnitude < 60 && wheelDelta < 0))
{
_camera.transform.position += moveVector.normalized * wheelDelta * 2.0f;
}
}
}
// Update Camera Panning and Tilt handle
if (_dragState == CameraDragState.Begin)
{
// Update screen positions
_screenDragStartPosition = Input.mousePosition;
_screenDragCurrentPosition = Input.mousePosition;
_cameraDragStartPosition = transform.position;
if (_dragAction == CameraDragAction.Pan)
{
Ray pickRay = _camera.ScreenPointToRay(_screenDragStartPosition);
_worldDragStartPosition = ProjectRayToGround(pickRay);
_worldDragStartFarPosition = ProjectRayToCameraFarPlane(pickRay);
}
else if (_dragAction == CameraDragAction.Tilt)
{
_worldDragStartPosition = ProjectRayToGround(new Ray(_camera.transform.position, _camera.transform.forward));
_cameraDragCurrentViewportPosition = _camera.ScreenToViewportPoint(_screenDragStartPosition);
}
_dragState = CameraDragState.Move;
}
if (_dragState == CameraDragState.Move)
{
_screenDragCurrentPosition = Input.mousePosition;
if (_dragAction == CameraDragAction.Pan)
{
// This panning algorithm some people call it perfect panning as it maintains the cursor in the original position while panning.
Ray pickRay = _camera.ScreenPointToRay(_screenDragCurrentPosition);
var worldDragCurrentFarPosition = ProjectRayToCameraFarPlane(pickRay);
float moveDistance = (_cameraDragStartPosition - _worldDragStartPosition).magnitude
* (_worldDragStartFarPosition - worldDragCurrentFarPosition).magnitude
/ (_worldDragStartFarPosition - _worldDragStartPosition).magnitude;
var dir = (_worldDragStartFarPosition - worldDragCurrentFarPosition).normalized;
_camera.transform.position = _cameraDragStartPosition + dir * moveDistance;
}
else if (_dragAction == CameraDragAction.Tilt)
{
// This is a camera center targeted Orbital Rotation.
var lastViewportPosition = _cameraDragCurrentViewportPosition;
_cameraDragCurrentViewportPosition = _camera.ScreenToViewportPoint(_screenDragCurrentPosition);
var deltaViewportMovement = _cameraDragCurrentViewportPosition - lastViewportPosition;
_camera.transform.RotateAround(_worldDragStartPosition, Vector3.up, deltaViewportMovement.x * 60);
_camera.transform.RotateAround(_worldDragStartPosition, _camera.transform.right, -deltaViewportMovement.y * 60);
}
}
if (_dragState == CameraDragState.End)
{
_screenDragCurrentPosition = Input.mousePosition;
_dragState = CameraDragState.Idle;
_dragAction = CameraDragAction.None;
}
// Dont allow the camera go too far away
// This will create a sphere with center on [0,0,0] of size 80. If the camera move
// far from that clamp that value
if (_camera.transform.position.magnitude > 80)
{
_camera.transform.position = Vector3.ClampMagnitude(_camera.transform.position, 80);
}
}
private void OnEnable()
{
_dragAction = CameraDragAction.None;
_dragState = CameraDragState.Idle;
}