Runs, but does not respond to mouse clicks.

[robertflesch]

New to ImGui, but long time UI developer.
Running on Vulkan 1.3, latest ImGui, Windows 11, VS22

Running some sample code from ImGui FAQ.
It runs beautifully, I can see my mouse overs, but none of the controls responds to mouse clicks.

Recording.2024-06-06.145621.mp4

You can kind of see in demo I am hovering over Button, I am clicking on it. but number does not change, nor do any of the other controls respond. Also true for demo window. I can highlight an expandable control, but it never opens.

Looking at example code, I don't see where you are passing in the clicks from glfw, what am I missing?

while (!glfwWindowShouldClose(window)) {
glfwPollEvents();

ImGui_ImplVulkan_NewFrame();
ImGui_ImplGlfw_NewFrame();
ImGui::NewFrame();

{
    bool show_demo_window = true;
    bool show_another_window = false;
	ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
    static float f = 0.0f;
    static int counter = 0;

    ImGui::Begin("Hello, world!");                          // Create a window called "Hello, world!" and append into it.

    ImGui::Text("This is some useful text.");               // Display some text (you can use a format strings too)
    ImGui::Checkbox("Demo Window", &show_demo_window);      // Edit bools storing our window open/close state
    ImGui::Checkbox("Another Window", &show_another_window);

    ImGui::SliderFloat("float", &f, 0.0f, 1.0f);            // Edit 1 float using a slider from 0.0f to 1.0f
    ImGui::ColorEdit3("clear color", (float*)&clear_color); // Edit 3 floats representing a color

    if (ImGui::Button("Button"))                            // Buttons return true when clicked (most widgets return true when edited/activated)
        counter++;
    ImGui::SameLine();
    ImGui::Text("counter = %d", counter);
    ImGui::End();
}

ImGui::Render();

ImGui::EndFrame();
}

[ocornut]

The ImGui_ImplGlfw_InitXXX functions is installing callbacks or you can install them yourself and call the callbacks functions declared in imgui_impl_glfw.h.

[robertflesch]

So I reviewed my code, checked to make sure that I was calling ImGui_ImplGlfw_InitForVulkan, and indeed I do. As well as calling ImGui_ImplVulkan_Init. I would have thought that if I was seeing the mouse move messages, I would be getting the mouse click messages as well. Any clues as to how to debug it?

void Renderer::imgui_init() {
ImGui_ImplGlfw_InitForVulkan(this->window, false);
ImGui_ImplVulkan_InitInfo init_info = {};
init_info.Instance = _manager->getInstance();
init_info.PhysicalDevice = _manager->getPhysicalDevice();
init_info.Device = _manager->getDevice();
init_info.Queue = _manager->getGraphicsQueue();
init_info.DescriptorPool = imguiPool;
init_info.MinImageCount = 3;
init_info.ImageCount = 3;
init_info.MSAASamples = VK_SAMPLE_COUNT_1_BIT;

ImGui_ImplVulkan_Init(&init_info, renderPass);

}

[robertflesch]

Found the problem!
ImGui_ImplGlfw_InitForVulkan(this->window, false); Does NOT install callbacks, changing it to true does!
Thx for the help.