Inverted stylus detection

[hansemro]

Issue:

Godot does not care about whether the stylus is inverted or not. However, drawing projects like Lorien would care about reaching feature parity with other drawing tools that do make the distinction.

Relevant development branch

https://github.com/hansemro/godot/commits/eraser-detect-3.x
https://github.com/hansemro/godot/tree/eraser-detect-4

API Changes

• Added pen_inverted boolean property under InputEventMouseMotion
  • Added void set_pen_inverted(bool)
  • Added bool get_pen_inverted(void)

Tasks/Status/Notes:

• Add pen_inverted property
• Add pen_property getter/setter
• Linux/X11
  • simple strstr implementation based off https://gitlab.com/gnome/gtk/-/blob/master/gdk/x11/gdkdevicemanager-xi.c#L235
  • https://www.x.org/releases/X11R7.6/doc/man/man3/XIQueryDevice.3.xhtml
  • https://gitlab.freedesktop.org/xorg/lib/libxi/-/blob/master/include/X11/extensions/XInput2.h
  • get slave device id to read device name
• Windows
  • https://developer-docs.wacom.com/intuos-cintiq-business-tablets/docs/windows-ink-basics
  • https://developer-docs.wacom.com/intuos-cintiq-business-tablets/docs/wintab-overview
  • https://developer-docs.wacom.com/intuos-cintiq-business-tablets/docs/wintab-reference#packet
  • https://github.com/mingw-w64/mingw-w64/blob/35fa6bdbc14383c9078520492974ff5ab31ba796/mingw-w64-headers/include/winuser.h#L2679-L2680
  • winink support
  • wintab support
• macOS
  • https://developer.apple.com/documentation/appkit/nspointingdevicetype
• Android
  • https://source.android.com/devices/accessories/stylus
• iOS: unexplored
• HTML5: unexplored