imgui-ws

Dear ImGui over WebSockets

This is a small library that allows to stream a Dear ImGui scene to multiple WebSocket clients at once. This is achieved by sending Dear ImGui's DrawData structure which is then rendered in the browser using WebGL. To reduce the amount of network traffic, we send only the diffs between sequential frames (for more info - see #1).

Live examples

These are sample applications using imgui-ws, running on a Linode 2GB instance:

Note that these examples are "headless". This means that no graphics backend (like OpenGL, SDL, Vulkan, etc) is needed on the server, because it does not render anything. The application just generates the Dear ImGui draw data and sends it to any connected WebSocket clients where the actual rendering occurs. This has the advantage of being able to run applications with Dear ImGui interface on almost any kind of hardware, even one without a monitor or a graphics card. For example, the applications can run on a Raspberry Pi, or on a cloud VM as in the examples above.

Tools

There are a few tools that help with the development and the optimization of the ImDrawData compression. To build the SDL-based tools, use cmake -DIMGUI_WS_SUPPORT_SDL2=ON.

• record-sdl2

  Record the ImDrawData for all rendered frames in a Dear ImGui session

  ./bin/record-sdl2 session.imdd
  

• replay-sdl2

  Replay a session recorded with the record-sdl2 tool

  ./bin/replay-sdl2 session.imdd
  

• compressor-benchmark

  Run the available ImDrawData compression algorithms on various pre-recorded Dear ImGui sessions. Reports compression ratio, average required bandwidth and cpu utilization:

  ./bin/compressor-benchmark session0.imdd [session1.imdd] [session2.imdd] [...]
  

Building & running

# build
git clone https://github.com/ggerganov/imgui-ws --recursive
cd imgui-ws && mkdir build && cd build
cmake ..
make

# running
./bin/demo-null 5000

Open some browsers and point them to http://localhost:5000/

Dependencies

• uWebSockets
• SDL2 - optional, used by some of the examples and tools

Screenshot

Credits

• This project is heavily inspired by https://github.com/JordiRos/remoteimgui
• Most of the JS code is taken from https://github.com/flyover/imgui-js