swoolcock / ImGuiHelper

A helper mod for Celeste that allows other code mods to use DearImGui.

ImGuiHelper

A Celeste helper mod that provides ImGui.NET bindings to other code helpers.

Dear ImGui is a library that provides an Immediate Mode Graphical User Interface API for coders to design and draw simple overlays very quickly. It's mostly used for tools and debugging, not for actual gameplay.

tl;dr: Fancy buttons and windows in Celeste.

For code modders:

This requires the Core build of Everest, it will not run on the .NET Framework or Mono builds.

1. Add a package reference to ImGui.NET: <PackageReference Include="ImGui.NET" Version="1.89.4" />
2. Add an assembly reference to ImGuiHelper.dll (stripped, if you want).
3. Make one or more classes that inherit from ImGuiHandler.
4. In these classes, override the Render method.
   1. Call ImGuiNET.ImGui.Begin("Some Window Name");
   2. Make other calls to ImGui to create your interface.
   3. Call ImGuiNET.ImGui.End();
5. Register the handler classes by calling ImGuiManager.Handlers.Add(someHandler);.

• There is a simple mouse cursor that can be shown if desired (you probably do). Be warned that I am not an artist.
• The entire GUI is drawn to a single render target before Engine.Render, and then that is drawn over the screen after Engine.Render.
• You can make as many windows in a single handler as you like, as long as the Begin and End calls are balanced.
• You should probably also ensure you never have more than one instance of a single handler registered.
  (Check with ImGuiManager.Handlers.OfType<MyHandler>().Any())
• Windows don't have to be rendered; if you only want to display the window in certain situations then you can override the Update method in the handler to decide what to do. This is executed after Engine.Update
• Docking is enabled by default.

For players:

You only need to install this if it's a dependency of something else.

Commands:

• imguidemo : Opens the default Dear ImGui demo window.
• imguiclear : Removes all handlers and their corresponding windows.
• scene : Opens a work-in-progress scene viewer that shows all entities in the current scene.

Settings:

• Show Mouse Cursor On Startup (On/Off) : Defines whether the mouse cursor should display when the game starts, defaults to Off.
• Toggle Mouse Cursor (Binding) : Defines a hotkey to toggle the mouse cursor, unbound by default.