"hello, world" with Dear ImGui

Dear ImGui is a great library but it may not be easy to get a simple "hello, world". Indeed, Dear ImGui doesn't handle the display, keyboard and mouse by itself. A backend is required to do this:

You will need a backend to integrate Dear ImGui in your app. The backend passes mouse/keyboard/gamepad inputs and variety of settings to Dear ImGui, and is in charge of rendering the resulting vertices.

A backend is something like SDL or OpenGL, stuffs that I am absolutely not familiar with, so it took me a while just to display a simple text.

Here is an "hello, world" project so you can get started easily!

Run the project

The project builds with CMake.

From the command line:

git clone https://github.com/Bktero/HelloWorldWithDearImGui
cmake HelloWorldWithDearImGui\ -B build -G Ninja
cmake --build build
./build/HelloWorldWithDearImGui.exe

It will clone this repository, generate build files for Ninja with GCC, build the project and run the application. Of course, you can select the generator and compiler you want. I have successfully built the project on Windows 10 with mingw64/GCC 9.2 (with both Make and Ninja) and MSVC 2019.

Under the hood

Download dependencies from GitHub

The project uses the OpenGL + GLFW backend.

The FetchContent module is used in CMakelists.txt to download the dependencies from GitHub:

• Dear ImGui, obviously.
• GLFW, used for the backend.
• GLEW, also used for the backend.

Note that the official GitHub for GLEW is https://github.com/nigels-com/glew but it doesn't build properly with CMake. This issue suggests to use an alternative repository: https://github.com/Perlmint/glew-cmake.

C++ standard version

Dear ImGui requires C++11. In C++98, GCC emits warnings:

warning: anonymous variadic macros were introduced in C++11 [-Wvariadic-macros]