Imgui Problem Demo

bool prepareDockspace(const char *name) {
	static ImGuiDockNodeFlags opt_flags = ImGuiDockNodeFlags_None;
	ImGuiWindowFlags window_flags = ImGuiWindowFlags_MenuBar;
	if (opt_flags & ImGuiDockNodeFlags_PassthruCentralNode)
		window_flags |= ImGuiWindowFlags_NoBackground;

	ImGui::PushStyleVar(ImGuiStyleVar_WindowPadding, ImVec2(0.0f, 0.0f));
	bool win_open = ImGui::Begin(name, nullptr, window_flags);
	ImGui::PopStyleVar();
	if (win_open) {
		opt_flags |= ImGuiDockNodeFlags_None;

		// Dockspace
		ImGuiIO& io = ImGui::GetIO();
		if (io.ConfigFlags & ImGuiConfigFlags_DockingEnable)
		{
			ImGuiID dockspace_id = ImGui::GetID(name);
			ImGui::DockSpace(dockspace_id, ImVec2(0.0f, 0.0f), opt_flags);
		}

		if (ImGui::BeginMenuBar()) {
			if (ImGui::BeginMenu("File")) {
			}
			ImGui::EndMenuBar();
		}
	}

	ImGui::End();

	return win_open;
}

void run(std::string material_name_) {
	prepareDockspace(material_name_.c_str());
	if (ImGui::Begin((material_name_ + " Viewport").c_str())) {
		ImGui::End();
	}
	if (ImGui::Begin((material_name_ + " Properties").c_str())) {
		char name_buff[256];
		name_buff[0] = 0;
		ImGui::InputText("Name", name_buff, 256);
		ImGui::End();
	}
}

run("A");
run("B");