godot-docs/tutorials/engine/mouse_and_input_coordinates.rst

.. _doc_mouse_and_input_coordinates:

Mouse & Input Coordinates
=========================

About
-----

The reason for this small tutorial is to clear up many common mistakes
about input coordinates, obtaining mouse position and screen resolution,
etc.

Hardware Display Coordinates
----------------------------

Using hardware coordinates makes sense in the case of writing complex
UIs meant to run on PC, such as editors, MMOs, tools, etc. Yet, make not
as much sense outside of that scope.

[STRIKEOUT:The only way to reliably obtain this information is by using
functions such as:]

**This method is no longer supported:** It was too confusing and caused
errors for users making 2D games. Screen would stretch to different
resolutions and input would stop making sense. Please use the
``_input`` function

::

    OS.get_video_mode_size()
    Input.get_mouse_pos()

However, this is discouraged for pretty much any situation. Please do
not use these functions unless you really know what you are doing.

Viewport Display Coordinates
----------------------------

Godot uses viewports to display content, and viewports can be scaled by
several options (see :ref:`doc_multiple_resolutions` tutorial). Use, then, the
functions in nodes to obtain the mouse coordinates and viewport size,
for example:

::

    func _input(ev):
       # Mouse in viewport coordinates

       if (ev.type==InputEvent.MOUSE_BUTTON):
           print("Mouse Click/Unclick at: ",ev.pos)
       elif (ev.type==InputEvent.MOUSE_MOTION):
           print("Mouse Motion at: ",ev.pos)

       # Print the size of the viewport

       print("Viewport Resolution is: ",get_viewport_rect().size)

    func _ready():
       set_process_input(true)

Alternatively it's possible to ask the viewport for the mouse position

::

    get_viewport().get_mouse_pos()