Segfault in `ImGui_ImplVulkan_LoadDynamicRenderingFunctions`

[vaylor27]

Version/Branch of Dear ImGui:

Version 1.91.9 WIP, Branch: master.

Back-ends:

imgui_impl_sdl3.cpp + imgui_impl_vulkan.cpp

Compiler, OS:

Windows 11 + MSVC && MacOS 13 Ventura + Apple Clang

Full config/build information:

No response

Details:

upon calling ImGui_ImplVulkan_Init, there is a segmentation fault in ImGui_ImplVulkan_LoadDynamicRenderingFunctions, due to it calling ImGui_ImplVulkan_GetBackendData, which gets the value of ImGui::GetIO().BackendRendererUserData. The problem arises in the fact that this isn't set until line 1143 of imgui_impl_vulkan.cpp, while ImGui_ImplVulkan_LoadDynamicRenderingFunctions is called before this, at line 1128. On top of this, the value cannot even be set manually, as imgui will assert, claiming that the renderer backend has already been initialized.

Proposed solution: Move lines 1124 - 1134 (the if statement containing the check for dynamic rendering) after the value for ImGui::GetIO().BackendRendererUserData is set.

Screenshots/Video:

No response

Minimal, Complete and Verifiable Example code:

[ocornut]

Caused by 890ead6, 12963f5, e1ae7db pushed yesterday.

Were you also using VK_NO_PROTOTYPES or a specific loader?

I have now pushed a fix ec4cd2c which unfortunately required to add an ApiVersion parameter to ImGui_ImplVulkan_LoadFunctions(), because that other path would have had the same problem without an easy fix.