Game engine part of the tutorial uses deprecated Dear ImGui functionality

[SaschaWillems]

This was brought up to me by Omar, the creator of Dear ImGui: The Dear ImGui setup chapter of the tutorial is using outdated/deprecated functions:

• GetTexDataAsRGBA32() was marked obsolete in June 2025 and is a path that does not support e.g. dynamic font textures and will likely be unsupported in 2026. See https://github.com/ocornut/imgui/blob/master/docs/BACKENDS.md#rendering-adding-support-for-imguibackendflags_rendererhastextures-192
• ImGuiVulkanUtil::handleKey() in that web uses API that were deprecated in 2022 & went unsupported in nov 2024. The TL;DR is that:
  io.KeysDown[key] = true ==> io.AddKeyEvent(key, true).
  io.MousePos = pos; ==> io.AddMousePosEvent(pos); etc.
• (If that util/framework is using GLFW honestly it should be using imgui_impl_glfw backend for platform stuff, otherwise 100% chance you having missing features or bugs. But it seems reasonable that a vulkan tutorial rewrites a vulkan renderer instead of usig imgui_impl_vulkan.)

[gpx1000]

👍 Thank Omar. I think I started writing the Game Tutorial around May of 2025 so the first one makes sense. The second one looks like I just borrowed code from one of our internal engines. I'll update both.

The problem with imgui_impl_glfw backend is that the tutorial also works in Android and in the future we have an issue to support Direct 2 Display. So, GLFW being not a core requirement is probably a good thing. However, I'll investigate if I can use imgui_impl_glfw for platforms that support glfw instead of rolling our own.