Summary

NetImgui is a library to remotely display and control Dear ImGui menus with an associated NetImgui Server application. Designed to painlessly integrate into existing codebase with few changes required. It allows any program using Dear ImGui to receives input from a remote PC and then forwards its UI rendering to it (textures, vertices, indices, draw commands).

Purpose

Initially created to assist game developers in debugging their game running on a game console or smartphone, from a PC. However, its use extends to wider applications. The only requirements are that a program is using Dear ImGui using C++ and available TCP/IP communications.

1. UI for devices without display/input.

Some applications lack display and inputs access, preventing feedbacks and easy control. It could be a program running on a Raspberry Pie device, or Unreal 4 running in server mode, etc . . . Using NetImgui allows the display of a user interface with full control on your PC while the logic remains on the client application itself.

Note: SampleNoBackend demonstrate using Dear ImGui without any backend implementation. It is a simple console application connecting to the NetImguiServer to draw its Imgui content. There is no rendering/input backend that's usually require by Dear ImGui

2. Ease of use

While inputs might be available on a particular device (keyboard, gamepad, . . .), it might still not be convenient for certain aspect. For example, text input is still more comfortable on a physical keyboard than on a smartphone. Idem for gaming consoles with gamepads control or VR development.

3. Declutter display

Dear ImGui is often used to display relevant debug information during development, but UI elements can obscure the regular content. NetImgui sends the UI content to a remote window, leaving the original display clutter-free and with the freedom to use the entire screen for more elaborate content.

Before

With NetImgui

How it works

Here is a quick overview of the logic behind using the NetImgui Server and one (or more) program using the NetImgui Client code.

1. (NetImgui Server) Capture user's inputs with mouse/keyboard

2. (NetImgui Server) Send the Inputs to client and request a draw update

3. (NetImgui Client) Draw the Dear ImGui content normally (without need to display on client)

4. (NetImgui Client) Send the drawing results to server

5. (NetImgui Server) Receives the drawing result and display them

6. Go back to 1

Note

The NetImgui Server application currently compiles under Windows and Mac, but few changes are required to properly have it running under other Operating Systems. To compile for Mac, modify NetImguiServer_App.h to enable the GLFW_GL3 rendering API.

Integration

1. Download the latest version of the NetImgui library.
2. Add the content of Code\Client to your codebase.
3. In your codebase:
   • [once]
     • Call NetImgui::Startup() (at program start).
     • Call NetImgui::ConnectToApp() or NetImgui::ConnectFromApp().
     • Call NetImgui::Shutdown() (at program exit).
   • [every redraw]
     • Draw your ImGui menu as usual.
     • If Dear ImGui 1.80 and lower (or want frameskip support).
       • Replace call to ImGui::NewFrame() with NetImgui::NewFrame().
       • Replace call to ImGui::Render() / ImGui::EndFrame() with NetImgui::EndFrame().
4. Start the NetImgui server application and connect your application to it.

• More integration details can be found on the Wiki.
• Multiple samples are also provided in the depot, providing additional insights.

Note

• Connection between NetImgui Server and a netImGui Client can be achieved in 4 different ways.

• Server waits for connection and :

  • (A) Client calls ConnectToApp() with the Server address.

• Client calls ConnectFromApp() then waits for connection and :

  • (B) Server configure the Client's address and connect to it.
  • (C) Server is launched with the Client's address in the commandline.
  • (D) Server receives a Client's address from another application, through Windows named pipe : \.\pipe\netImgui'.

• Advanced: Different Dear ImGui content can be displayed locally and remotely at the same time. Look at SampleDualUI for more information.

• NetImgui::IsConnected() and NetImgui::IsDrawingRemote() can be used during Dear ImGui drawing, helping to make selective decisions on the content to draw based on where it will be displayed.

Dear Imgui versions

• Tested against Dear ImGui versions 1.71 to 1.90.
• Note: Should support other versions without too much difficulties.
• Note: See Build\GenerateCompatibilityTest.bat for an exact list of tested versions.

Related

Related projects making use of NetImgui.

• Unreal NetImgui : Unreal 4 plugin adding access to Dear ImGui and NetImgui functionalities. Unlike the next plugin, it is a simple implementation with only remote access possible (no Dear ImGui drawing over the game).
• Unreal ImGui : Unreal 4 Plugin adding Dear ImGui drawing support over your game and editor display. The net_imgui branch of this repository contains an integration of this NetImgui library for remote access and is ready to go.
• For Unreal 4 developpers with their own Dear ImGui integration, Unreal NetImgui has support for an Imgui Unreal Commands window that can be of interest. The code can easily be imported in your own codebase, with no dependency to Unreal NetImgui proper.

Release notes

To do

• Support of additional texture formats
• Handle Linear/sRGB vertex color format
• Add logging information to NetImgui Server Application
• Add new Dear ImGui multi windows support (docking branch)
• Commands to assign custom backgrounds
• Add compression to data between Client and Server
• Support of monitor DPI

Version 1.10

(2023/12/30)

• API Changes
  • ConnectToApp() and ConnectFromApp() functions now accept a callback to be used by the NetImgui Server when wanting to update the font to a specific DPI scale.
    • Can be left untouched, with null used by default.
    • Without a callback, we apply the text scaling to ImGuiIO.FontGlobalScale instead of requesting the generation of a new font with increased pixel size.
    • Using ImGuiIO.FontGlobalScale gives a blurier text result than recreating the font with the exact DPI needed.
    • See SampleFontDPI for more info.
  • SendDataTexture() now support a new texture format kTexFmtCustom.
    • It requires that the dataSize parameter is specified since we can't deduce it anymore (but not used for other formats)
    • It allows user to send a texture command with custom data that also needs to be added to NetImguiServer codebase.
    • This could be used for movie streaming, etc...
    • See SampleTexture for more info.
• Upgraded Dear ImGui support to 1.90
• Added monitor DPI support
  • The Server now scale the text up on a high resolution monitor, so it can still be read
  • The Server font atlas is regenerated with a higher pixel size to match the resolution
  • The Client connected will be asked to regenerate their font atlas if they provided a callback when connecting
    • When this callback is received, the client codebase should regenerate the font atlas using the provided scale
    • When no callback has been assigned, the client automatically relies on ImGuiIO.FontGlobalScale when drawing (blurier results)
    • See SampleFontDPI for more info.
• Added Clipboard support
  • Can now seamlessly use text clipboard between Client and Server!
  • Text copied on the Server PC is now sent over to the NetImgui Clients and can be pasted inside their Dear ImGui content
  • Text copied inside the Client's Dear ImGui content is now received by the Server PC and can be used on it
• Shared Client configs
  • When adding a Client configuration on the NetImgui Server application, the property Shared can now be specified
  • When enabled, it will save the config in a User Directory instead of the current Working Directory
  • This means that user can have NetImgui Server applications in various locations, but they can all still share the same Client Configs.
  • Note: Requires that the function HAL_GetUserSettingFolder() is implemented in the NetImgui Server codebase. It has been done for Windows.
• Various small changes and fixes
  • When the NetImgui Server config file netImgui.cfg is detected readonly, now tries to create a second one. This should help if user submit the default config file to perforce but still want to add new Clients.
  • Quickly typed text was dropping characters when received by Client
  • DirectX textures error when quickly recreating them

Older

Release Notes

Contact

It seems that various gaming studios are making use of this code. I would enjoy hearing back from library users, for general comments and feedbacks. Always interested in learning of people usercase. I can be reached through my GitHub profile (email or twitter) or creating a new entry in GitHub Issue.

Credits

Sincere thanks to Omar Cornut for the incredible work on Dear ImGui.

Support of image formats via stb_image.h by Sean Barrett (public domain).

Support of Solutions generation via Sharpmake by Ubisoft (public domain).

Support of Posix sockets thanks to Aaron Lieberman.

Support of json save file via nlohmann json