This uses a newer browser API to get physical scancodes, but still
uses the (deprecated) event field that we were already using for
scancodes, but for keycodes instead now, which appears to be more
accurate.
Since keyboard layout isn't (generally) available to web apps, this
adds an internal interface to send key events with both scancode
and keycode to SDL's internals, instead of sending just scancodes and
expecting SDL to use its own keymap to generate keycodes.
Future work in this area would be to use the keyboard layout APIs
on browsers that support them, which would allow us to use SDL's
usual keymap code and not rely on a deprecated browser API, but
until we get there, this patch gives significantly more correct
results than we would have before.
Fixes#2098.
Simple DirectMedia Layer is a cross-platform development library designed
to provide low level access to audio, keyboard, mouse, joystick, and graphics
hardware via OpenGL and Direct3D. It is used by video playback software,
emulators, and popular games including Valve's award winning catalog
and many Humble Bundle games.
More extensive documentation is available in the docs directory, starting
with README.md