sokol_app.h: add a tool_type field to the sapp_touchpoint struct (valid on Android)

[Wertzui123]

This makes it possible to differentiate between different types of touch input.
See: https://developer.android.com/ndk/reference/group/input#amotionevent_gettooltype for the documentation of this function
I've tested it and it successfully showed 1 for finger input and 2 for S-Pen input.

I'm unsure if adding a new field to the event struct is the way to go; maybe we should provide the user directly with the AMotionEvent and the pointer_index (e and idx variables) instead so that they can then use arbitrary NDK functions in their callbacks.

[billzez]

I think it might make more sense to emit mouse events so that Android matches other platforms, and we don't have to use two different APIs to handle mouse input.

[Wertzui123]

No, I don't think so. Afaik, mouses on Android already emit a mouse event, but touch should remain touch.

[Wertzui123]

I've noticed my previous implementation (a field in the event struct) didn't make much sense in the multi-touch architecture of sokol_app.h.
Instead, I have changed it to a field of the sapp_touchpoint struct now, which should also be a smaller bc break for wrappers.

[billzez]

Actually, android has a single API for both mouse and touch, and calls them "pointers". Currently sokol creates touch events, but not mouse events for android.

[Wertzui123]

Oh, okay, I didn't know that. Well, on one hand, it makes sense, but on the other hand, you normally have only 1 mouse, but multiple fingers, so it maybe makes sense to separate it.

[floooh]

I'll start looking into this PR now.

@billzez: I'm not a big fan of unified mouse and and touch events, for instance UWP also only has this sort of "pointer events", and it's quite a mess. It's better if the application decides to explicitely support touch vs mouse input, and if it wants to unify those two.

[floooh]

@Wertzui123: Do you know if there's a documentation somewhere what the integer return value from AMotionEvent_getToolType() actually means? I have a hard time finding any useful documentation.

Also, I'll rename the field to android_tooltype, to make clear that it is only populated on Android.

PS: nevermind, found it: https://developer.android.com/reference/android/view/MotionEvent#TOOL_TYPE_FINGER

I'll add an sapp_android_tooltype enum with those values, and replace the plain integer with the enum.

[Wertzui123]

Do you know if there's a documentation somewhere what the integer return value from AMotionEvent_getToolType() actually means? I have a hard time finding any useful documentation.

I think you are looking for this: https://developer.android.com/ndk/reference/group/input#anonymous-enum-38

Also, I'll rename the field to android_tooltype, to make clear that it is only populated on Android.

I used a generic name since we may want to add iOS support in the future too (if that's possible), but I'm fine with adding an android prefix for now.

I'll add an sapp_android_tooltype enum with those values, and replace the plain integer with the enum.

Good idea.

[floooh]

Please ignore the Github Actions error, this seems to be a regression in Nim.

[floooh]

since we may want to add iOS support in the future too

I did some quick googling too but haven't found anything (neither iOS nor web APIs). If iOS provides that sort of information then we should go back from the android prefixes to generic names, but as long as it's not a multi-platform feature it's better to keep the prefix.

[floooh]

Ok, merged, I did the following changes on top:

2a1efce

(argh, extra whitespace line, I'll remove that too...)
PS: and a comment typo...

[Wertzui123]

Thanks for merging!