EyeAuras.ImGui.Net

Based on Dear ImGui by Omar Cornut — original repository: https://github.com/ocornut/imgui (@ocornut). The public API mirrors ImGui.NET by Eric Mellino. All credit for the design of Dear ImGui belongs to its original authors.

A pure-managed, 1:1 C# port of Dear ImGui for modern .NET — no native cimgui, no DllImport, no P/Invoke. It produces the same ImDrawData (vertices / indices / draw commands) as Dear ImGui from a drop-in, ImGui.NET-compatible ImGuiNET.ImGui facade, so your existing rendering backend keeps working.

(The demo above is the port's own ShowDemoWindow() output, rasterized to a PNG entirely in managed code — see the QA section.)

Why

• Fully managed — runs anywhere .NET runs, no native binaries to ship or load.
• Allocation-free at steady state (verified by tests).
• Fast for frame/layout/table work — it skips the per-call marshalling that the native binding pays (e.g. an empty frame is ~13× faster than native ImGui.NET; text-heavy paths are currently slower — see notes).
• Faithful — text metrics and layout match real Dear ImGui exactly (verified against the native library).

Use

using ImGuiNET;

ImGui.CreateContext();
var io = ImGui.GetIO();
io.DisplaySize = new Vector2(1280, 800);

// per frame:
ImGui.NewFrame();
ImGui.Begin("Hello");
if (ImGui.Button("Click me")) { /* ... */ }
ImGui.End();
ImGui.Render();
var drawData = ImGui.GetDrawData(); // feed to your renderer

Build & test

dotnet build Sources/EyeAuras.ImGui.Net.slnx -c Release
dotnet test  Sources/EyeAuras.ImGui.Net.Tests/EyeAuras.ImGui.Net.Tests.csproj -c Release

Requires the .NET 8 SDK. The library and its tests are self-contained (no submodules, no native code). CI builds and tests every push.

QA

The draw output is verified in four layers — structural invariants, golden snapshots, a differential check against native Dear ImGui, and a software rasterizer that renders to pixels. See docs/QA.md.

Credits & license

Dear ImGui and ImGui.NET are both MIT-licensed; this port stands on their work — see the linked repositories above. Submodules under Submodules/ vendor the upstream sources for reference.