feat: support for 1.92.0

[majvax]

This is primarily a proof of concept rather than a production-ready implementation. I am more than happy to collaborate with the maintainers to refine this update according to your preferences and project standards.

Please note: This PR should not be merged in its current state. It lacks proper testing, and the code was written during my class, so there may be performance or memory issues that I have overlooked.

My work is based on the official documentation and the SDL3 renderer backend.

I welcome any suggestions or guidance on how to improve this contribution.

Reference:

• sdl3 1.92.0 update commit
• official doc to update backend for 1.92.0

[majvax]

The second commit is based of #319. As noted in the v1.91.9 changelog, parameters tint_col and border_col have been remove from ImGui::Image. The signature is deprecated and remplaced by ImGui::ImageWithBg.

After some testing, I found that the minimum supported version for these changes is v1.92.0. The new interface for textures introduced in this version breaks compatibility with earlier releases, so support for versions prior to 1.92.0 is not feasible. The good news is that these updates are compatible up to v1.92.2b, and ImGui can now be compiled with IMGUI_DISABLE_OBSOLETE_FUNCTIONS enabled.

[majvax]

I believe upgrading to 1.92.0 is necessary, as ImGui will require this update moving forward. As quoted from the doc:

"In order to move forward and take advantage of all new features, support for ImGuiBackendFlags_RendererHasTextures will likely be REQUIRED for all backends before June 2026"

[majvax]

@ChrisThrasher What do you think of this?

[ChrisThrasher]

So you’re saying that supporting ImGui 1.92 means all prior versions become unusable? We have to raise the minimum from 1.91.1 to 1.92?

[majvax]

That’s basically what I’m saying, yes. Certainly, we could use macros to provide version-specific code, but I don’t think that fits the modern C++ approach of SFML.

[ChrisThrasher]

Does ImGui provide macros for detecting the current version?

[majvax]

I didn't look at it myself but trusting this comment I would say yes.

[mikademus]

Would it be helpful to stage the updates rather than try to get all fixes in at once? It seems that the most urgent change is the texture changes. ImGui-SFLM overloads ImGui::Image and ImGui::ImageButton for sf::Texture, sf::Sprite and sf::RenderTexture, and I think basically need updates to the texture ID semantic? This seems separate from the font revisions, and a manageable high-reward step.