French Keyboard and Backend SDL2 - Several keys are not checkable with IsKeyDown

[oschemid]

Version/Branch of Dear ImGui:

Version 1.90.2

Back-ends:

imgui_impl_sdl2.cpp

Compiler, OS:

Windows11 + VS2022

Full config/build information:

No response

Details:

Hello,

I uses the function IsKeyDown to check if the user presses a key. With my french keyboard, I cannot check the key called SDLK_Minus on an US Keyboard (the key after the 0), because the library SDL2 maps the key on SDLK_RIGHTPAREN.

I checked with the tools Demo-> Inputs & Focus and I found that several keys are not displayed in "Keys Down":
SDL_scancode_minus which is mapped to SDLK_RIGHTPAREN on my keyboard layout
SDL_scancode_period mapped to SDLK_COLON
SDL_scancode_slash mapped to SDLK_EXCLAIM
SDL_scancode_baskslash mapped to SDLK_ASTERISK
...

Do I have a solution, without modifying the function ImGui_ImplSDL2_KeycodeToImGuiKey to fix this issue ?

Regards

Screenshots/Video:

No response

Minimal, Complete and Verifiable Example code:

// Here's some code anyone can copy and paste to reproduce your issue
ImGui::Begin("Example Bug");
MoreCodeToExplainMyIssue();
ImGui::End();

[PathogenDavid]

Semi-related issue with other non-US keyboards: #7136

[ocornut]

@oschemid See #7201 (comment) for further work on this.

I don't yet know what is the best solution for this. French appears to be the one with most holes but I presume other European languages would likely be affected, so I'd like to data for some of them.

[oschemid]

Thank you @ocornut
I fixed temporarily the function ImGui_ImplSDL2_KeycodeToImGuiKey waiting for best implementation.
If I can help you, don't hesitate

[ocornut]

I believe the SDL backend should rely more on scancode and only use keycodes for alpha-numeric keys. Linking to #7672

[ocornut]

I have pushed a rather important change a9e5382 where SDL backend now rely on scancode for OEM keys.
This AFAIK fixes most issues with French layouts.

Ref https://docs.google.com/spreadsheets/d/1TwAHusBpxf_avmk03FUSrni17RP8qXmbJeDzs5fs0nY/edit?pli=1&gid=0#gid=0