/// <summary>
/// Rotate/pan/zoom model in response to mouse input.
///
/// Note: This code uses Unity's Input Manager
/// (`Input`) to read mouse input, whereas previous revisions
/// used IMGUI events such as `EventType.MouseDown`.
/// I switched to solely using `Input` because I found that
/// `EventType.MouseDrag` events were not being generated
/// in WebGL while holding down either the middle mouse
/// button or the right mouse button, and I couldn't figure
/// out why.
/// </summary>
protected void ProcessMouseInput()
{
// if any GUI element (e.g. checkbox, slider) currently
// has focus
if (GUIUtility.hotControl != 0)
{
return;
}
// Note: The test for Input.touchCount != 0 ensures
// that the code is only run in response to input from a
// *real* mouse, rather than mouse events simulated from
// a touch screen. It would be better/cleaner to set
// Input.simulateMouseWithTouches to false to achieve this
// separation, but I found that the setting has no effect
// (in Unity 2018.3). Moreover, there is a bug where
// Input.simulateMouseWithTouches is ignored under WebGL:
// https://forum.unity.com/threads/input-simulatemousewithtouches-is-ignored-in-webgl.388157/
if (Input.touchCount != 0)
{
return;
}
MouseButtons buttons = MouseButtons.None;
MouseAction mouseActions = MouseAction.None;
float deltaX = 0f;
float deltaY = 0f;
float deltaZ = 0f;
if (Input.GetMouseButton(0))
{
buttons |= MouseButtons.LeftButton;
}
if (Input.GetMouseButton(1))
{
buttons |= MouseButtons.RightButton;
}
if (Input.GetMouseButton(2))
{
buttons |= MouseButtons.MiddleButton;
}
if (Input.mouseScrollDelta != Vector2.zero)
{
mouseActions = MouseAction.Zoom;
deltaZ = Input.mouseScrollDelta.y;
}
// Detect mouse drag events by comparing the current
// mouse button states and cursor position to
// those of the previous frame.
if (buttons != MouseButtons.None &&
buttons == _prevMouseState.Buttons &&
_prevMouseState.Position.HasValue)
{
Vector3 mouseDelta = Input.mousePosition - _prevMouseState.Position.Value;
if (buttons.HasFlag(MouseButtons.LeftButton))
{
mouseActions |= MouseAction.Rotate;
}
if (buttons.HasFlag(MouseButtons.RightButton))
{
mouseActions |= MouseAction.Pan;
}
deltaX = mouseDelta.x;
deltaY = mouseDelta.y;
}
// Stop auto-spin ("Spin X" / "Spin Y")
// whenever the user clicks on the
// model/background.
if (Input.GetMouseButtonDown(0) ||
Input.GetMouseButtonDown(1) ||
Input.GetMouseButtonDown(2))
{
Gui.Instance.ResetSpin();
}
if (mouseActions.HasFlag(MouseAction.Rotate))
{
ModelManager.Instance.RotateAboutCenter(
new Vector3(deltaY, -deltaX, 0) * MouseRotateSpeed);
}
if (mouseActions.HasFlag(MouseAction.Pan))
{
CameraBehaviour.Instance.PanCamera(
new Vector3(-deltaX, -deltaY, 0) * MousePanSpeed);
}
if (mouseActions.HasFlag(MouseAction.Zoom))
{
CameraBehaviour.Instance.ZoomCamera(deltaZ * MouseZoomSpeed);
}
// Record current mouse position and button states
// for use in the next frame, so that we can detect when
// button states have changed.
_prevMouseState.Buttons = buttons;
_prevMouseState.Position = Input.mousePosition;
}
/// <summary>
/// Handle touch screen input (Android and WebGL).
///
/// Note: This code uses the `Touch` class
/// from Unity's old input system ("Input Manager").
/// At the time of coding, I was not aware that there
/// was a newer Unity input system ("Input System",
/// introduced in Unity 2019.1), which provides a new touch
/// input API via `InputSystem.EnhancedTouch.Touch`.
/// See https://forum.unity.com/threads/inputsystem-enhancedtouch-touch-and-unity-ads.779351/
/// The code below works fine and is likely to
/// be supported by Unity for a long time. But if I
/// ever need to make major changes, I should consider
/// using the new input system.
/// </summary>
protected void ProcessTouchInput()
{
// if user is currently interacting with an IMGUI control (e.g. a slider)
if (GUIUtility.hotControl != 0)
{
return;
}
// if touch screen input is not supported on the current platform
if (!Input.touchSupported)
{
return;
}
MouseAction mouseActions = MouseAction.None;
bool mouseDown = false;
float deltaX = 0f;
float deltaY = 0f;
float deltaZ = 0f;
// if number of fingers has changed
if (Input.touchCount != _prevTouchState.TouchCount)
{
_prevTouchState.PinchDist = null;
_prevTouchState.PinchMidpoint = null;
// perform mouse click actions when finger(s) first touch screen
if (_prevTouchState.TouchCount == 0)
{
mouseDown = true;
}
}
else if (Input.touchCount == _prevTouchState.TouchCount)
{
// perform mouse drag actions while number of fingers
// touching screen is > 0 and does not change
if (Input.touchCount == 1)
{
// one-finger drag -> rotate model
Touch touch = Input.GetTouch(0);
deltaX = touch.deltaPosition.x * 0.3f;
deltaY = -touch.deltaPosition.y * 0.3f;
mouseActions |= MouseAction.Rotate;
}
else if (Input.touchCount == 2)
{
Touch touch0 = Input.GetTouch(0);
Touch touch1 = Input.GetTouch(1);
// two fingers pinch -> zoom
float pinchDist = (touch1.position - touch0.position).magnitude;
if (_prevTouchState.PinchDist.HasValue)
{
mouseActions |= MouseAction.Zoom;
float pinchDelta = pinchDist - _prevTouchState.PinchDist.Value;
deltaZ = pinchDelta * 0.03f;
}
_prevTouchState.PinchDist = pinchDist;
// two-finger drag -> pan
Vector2 pinchMidpoint = (touch0.position + touch1.position) / 2.0f;
if (_prevTouchState.PinchMidpoint.HasValue)
{
mouseActions |= MouseAction.Pan;
Vector2 deltaMidpoint
= pinchMidpoint - _prevTouchState.PinchMidpoint.Value;
deltaX = deltaMidpoint.x * 1.0f;
deltaY = -deltaMidpoint.y * 1.0f;
}
_prevTouchState.PinchMidpoint = pinchMidpoint;
}
}
// stop auto-spin ("Spin X" / "Spin Y")
// whenever the user clicks on the
// model/background.
if (mouseDown)
{
Gui.Instance.ResetSpin();
}
if (mouseActions.HasFlag(MouseAction.Rotate))
{
ModelManager.Instance.RotateAboutCenter(
new Vector3(-deltaY, -deltaX, 0) * MouseRotateSpeed);
}
if (mouseActions.HasFlag(MouseAction.Pan))
{
CameraBehaviour.Instance.PanCamera(
new Vector3(-deltaX, deltaY, 0) * MousePanSpeed);
}
if (mouseActions.HasFlag(MouseAction.Zoom))
{
CameraBehaviour.Instance.ZoomCamera(deltaZ * MouseZoomSpeed);
}
_prevTouchState.TouchCount = Input.touchCount;
}