Emscripten: API requirements between Player and Browser

[Ghabry]

There is by now lots of interfacing between the Player and the Browser as part of the multiplayer projects.

I want to collect here what is currently used by the projects to unify this approach. Also with the goal to upstream some stuff.

@Gamizard @Flashfyre @CataractJustice could you please contribute what kinds of callbacks you added?
In both direction: Webbrowser -> Player and Player -> Webbrowser

Also which callbacks you would like to have but did not implement

List:

• Download Savegame (added by me in a branch as an enhancement for the File Scene, not merged yet)
• Upload Savegame (added by me in a branch as an enhancement for the File Scene, not merged yet)
• requesting a reset (added in my branch)
• scene refreshing to ensure that stuff like "new savegame" becomes visible directly (added in my branch)

[CataractJustice]

List:

• Set player sprite (Used by "/spriteset" command)
• Get current room id

Callbacks for setting up switch sync (Currently used only by Yume Nikki for weather switch):

• Turn switch sync on/off
• Add/Remove switch from whitelist

Chat:

• Send chat message
• Update chat input caret (Used for interaction between hidden web browser input and in-game input)
• Update chat input text (Used for interaction between hidden web browser input and in-game input)
• Is chat focused
• Print info message in chat
• Print player message in chat
• Change nametag (Called by chat to send name through game socket)

[Ghabry]

Was told that what I want to do with embind is unsupported due to risk of stack corruption.

The only supported solutions are:

• Remove Asynchify OR
• Use the emscripten fiber API

[Ghabry]

Closing this as the initial API for emscripten is finalized