Loading font to vsgImGui

[ComradeMashkov]

Hey, it's been a while since I've not checked last updates. Many things have changed and that absolutely lovely. But I have a problem with loading font to ImGui.

Before some commit (I don't know really which it was) I loaded fonts like that:

ImGui::CreateContext();
ImGuiIO& io = ImGui::GetIO();
ImFont* regularFont = io.Fonts->AddFontFromFileTTF("C:\\Windows\\Fonts\\segoeui.ttf", FONT_SIZE);
ImFontConfig config;
config.MergeMode = true;
static const ImWchar iconRanges[] = { ICON_MIN_WEB, ICON_MAX_WEB, 0 };
ImFont* iconsFont = io.Fonts->AddFontFromFileTTF((native_dir + "data\\fonts\\fontawesome-webfont.ttf").c_str(), FONT_SIZE, &config, iconRanges);

For now I tried different ways and I couldn't get them loaded properly. Is it the right way? Because for now it's not working :(

    auto ImGuiGroup = rocky::ImGuiIntegration::addContextGroup(app.displayManager, window);

    auto ImGuiContext = ImGuiGroup->imguiContext();
    ImGui::SetCurrentContext(ImGuiContext);

    ImGuiIO& io = ImGui::GetIO();
    io.Fonts->AddFontFromFileTTF(
        "C:/Windows/Fonts/segoeui.ttf",
        FONT_SIZE
    );
    static const ImWchar icon_ranges[] = { ICON_MIN_WEB, ICON_MAX_WEB, 0 };
    ImFontConfig cfg;
    cfg.MergeMode          = true;
    cfg.PixelSnapH         = true;
    cfg.GlyphMinAdvanceX   = FONT_SIZE;

    io.Fonts->AddFontFromFileTTF(
        (native_dir + "data/fonts/fontawesome-webfont.ttf").c_str(),
        FONT_SIZE,
        &cfg,
        icon_ranges
    );

    io.Fonts->Build();

    ImGuiGroup->add(MainGUI::create(app), app);

[gwaldron]

I don't know, but in RenderImGui there is a call to ImGui_ImplVulkan_CreateFontsTexture.
Perhaps you need to call this method again after changing fonts.
Just a wild guess though.

[ComradeMashkov]

I know 'bout this, tried to call ImGui_ImplVulkan_CreateFontsTexture() after io.Fonts->Build(), didn't work for me. Also tried to inline this into render() method inside MainGui struct, did not help.

[gwaldron]

Have you read this?
https://github.com/ocornut/imgui/blob/fd75bdccb033e74afeba44f500edc8fcef7eb023/docs/FONTS.md

[ComradeMashkov]

Yep, thanks. As has already mentioned @blacktorch, I called ImGui_ImplVulkan_CreateFontsTexture() after font adding, this did help. But, unfortunately, in the last commit this still causes crashes. I guess this is because of new ImGui integration, because previous version did work. So in my current implementation it looks like this:

    ImGuiIO& io = ImGui::GetIO();

#ifdef _WIN32
    io.Fonts->AddFontFromFileTTF("C:/Windows/Fonts/segoeui.ttf", FONT_SIZE);
#else
    #error "Font loading is only supported for Windows platforms"
#endif

    static const ImWchar iconRanges[] = { ICON_MIN_WEB, ICON_MAX_WEB, 0 };
    ImFontConfig cfg;
    cfg.MergeMode = true; cfg.PixelSnapH = true;

    io.Fonts->AddFontFromFileTTF(
        (ConfigManager::getInstance().getNativeDir() + "data/fonts/fontawesome-webfont.ttf").c_str(),
        FONT_SIZE,
        &cfg,
        iconRanges
    );

    ImGui_ImplVulkan_CreateFontsTexture();

    imguiRenderer->add(ASAD_NAMESPACE::ui::MainGUI::create(app));
    app.install(imguiRenderer);

    return app.run();

[ComradeMashkov]

Ok, so a little update coming from my experience. I've just pushed ImGui::SetCurrentContext(imguiRenderer->imguiContext()); right after auto imguiRenderer = rocky::RenderImGuiContext::create(window); and now everything is just fine.