Cannot load a font during frame rendering

[XMNXofficial]

Hello👋!
I want to load a ttf font into hello_imgui,but it can't work;

void Draw()
{
    ImFont* font1;    ImFont* font1;
    static bool bool1 = true;
    if (bool1)
    {
        font1 = HelloImGui::LoadFontTTF_WithFontAwesomeIcons(
            "/usr/share/fonts/truetype/ms-core-fonts/AndaleMo.TTF", 25.0f);
        bool1 = false;
    }

    ImGui::PushFont(font1);
    ImGui::Text("Hello");
    ImGui::PopFont();

⬇⬇It likely load success,but it show "unknown".
And when i select it,my program will crash ( show: 18762 segmentation fault (core dumped) ./hello_world ).

_example_integration.zip

[Pascal Thomet]

Hi,

Thanks for sharing your demo code, it makes it easier to answer.

Fonts need to be loaded at the appropriate moment during initialization. I updated a demo example to showcase how to load fonts.

First, you will need to create a function (or lambda) for loading the font:

hello_imgui/src/hello_imgui_demos/hello_imgui_demo_classic/hello_imgui_demo_classic.main.cpp

Lines 4 to 11 in 0a2859a

 // Demonstrate how to load additional fonts (fonts - part 1/3) 
 ImFont * gCustomFont = nullptr; 
 void MyLoadFonts() 
 { 
  
     HelloImGui::ImGuiDefaultSettings::LoadDefaultFont_WithFontAwesomeIcons(); // The font that is loaded first is the default font 
     gCustomFont = HelloImGui::LoadFontTTF("fonts/Akronim-Regular.ttf", 40.f); // will be loaded from the assets folder 
 } 

Then, you need to use RunnerParams and fill the correct callback:

hello_imgui/src/hello_imgui_demos/hello_imgui_demo_classic/hello_imgui_demo_classic.main.cpp

Lines 15 to 22 in 0a2859a

 HelloImGui::RunnerParams params; 
 params.appWindowParams.windowGeometry.size = {1280, 720}; 
 params.appWindowParams.windowTitle = "Dear ImGui example with 'Hello ImGui'"; 
 params.imGuiWindowParams.defaultImGuiWindowType = HelloImGui::DefaultImGuiWindowType::NoDefaultWindow; 
  
 // Fonts need to be loaded at the appropriate moment during initialization (fonts - part 2/3) 
 params.callbacks.LoadAdditionalFonts = MyLoadFonts; // LoadAdditionalFonts is a callback that we set with our own font loading function 
  

And then use the font:

hello_imgui/src/hello_imgui_demos/hello_imgui_demo_classic/hello_imgui_demo_classic.main.cpp

Lines 40 to 43 in 0a2859a

 // Demo custom font usage (fonts - part 3/3) 
 ImGui::PushFont(gCustomFont); 
 ImGui::Text("Custom font"); 
 ImGui::PopFont(); 

[XMNXofficial]

Thank you very much for your great help!