Add error handling in RdRenderer constructor

Dear ImGui for Godot Demo.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Godot.NET.Sdk/4.1.1">
+<Project Sdk="Godot.NET.Sdk/4.1.2">
   <PropertyGroup>
     <TargetFramework>net7.0</TargetFramework>
     <EnableDynamicLoading>true</EnableDynamicLoading>

README.md

@@ -1,13 +1,15 @@
 # Dear ImGui plugin for Godot 4 (C#)
 
+![](https://img.shields.io/static/v1?label=Godot&message=4.2&color=blue&logo=godotengine)
 ![](https://img.shields.io/static/v1?label=Godot&message=4.1&color=blue&logo=godotengine)
 ![](https://img.shields.io/static/v1?label=Godot&message=4.0&color=blue&logo=godotengine)
+
 ![](https://github.com/pkdawson/imgui-godot/actions/workflows/dotnet.yml/badge.svg)
 ![](https://github.com/pkdawson/imgui-godot/actions/workflows/godot.yml/badge.svg)
 
 ![screenshot](doc/screenshot.png)
 
-Dear ImGui is a popular library for rapidly building tools for debugging and development. This plugin, with the aid of [ImGui.NET](https://github.com/mellinoe/ImGui.NET), allows you to use ImGui in Godot with C#.
+[Dear ImGui](https://github.com/ocornut/imgui) is a popular library for rapidly building tools for debugging and development. This plugin, with the aid of [ImGui.NET](https://github.com/ImGuiNET/ImGui.NET), allows you to use ImGui in Godot with C#.
 
 After installing the plugin, usage is as simple as this:
 ```csharp
@@ -28,9 +30,6 @@ Download
 
 ## Getting Started
 
-### Demo
-
-Click `Build` in the top right, then run the project.
 
 ### Your project
 
@@ -52,12 +51,14 @@ Click `Build` in the top right, then run the project.
 
 In any Node's `_Process` method, use `ImGuiNET` to create your GUI. Just don't set the `ProcessPriority` in any of your Nodes to either `int.MinValue` or `int.MaxValue`.
 
-You can also connect to the `ImGuiLayout` signal, and use ImGui in the method which handles that signal. This is strongly recommended if you're using thread groups in Godot 4.1 or later.
+### Signals
+
+You can also connect to the `ImGuiLayout` signal, and use ImGui in the method which handles that signal. This is strongly recommended if you're using process thread groups in Godot 4.1 or later.
 ```csharp
 ImGuiLayer.Connect(OnImGuiLayout);
 ```
 
-### ImGuiLayer
+### Configuration
 
 If you want to customize fonts or other settings, create an `ImGuiConfig` resource, then open the scene `res://addons/imgui-godot/ImGuiLayer.tscn` and set its `Config` property.
 
@@ -103,4 +104,4 @@ Hack font distributed under the [MIT license](https://github.com/source-foundry/
 
 M PLUS 2 font licensed under the SIL Open Font License, Version 1.1.
 
-This plugin's functionality relies heavily on [ImGui.NET](https://github.com/mellinoe/ImGui.NET) by Eric Mellino
+This plugin's functionality relies heavily on [ImGui.NET](https://github.com/ImGuiNET/ImGui.NET) by Eric Mellino

addons/imgui-godot/ImGuiGodot/ImGuiGD.cs

@@ -71,13 +71,32 @@ public static void Init(Window mainWindow, Rid mainSubViewport, float? scale = n
         // there's no way to get the actual current thread model, eg if --render-thread is used
         int threadModel = (int)ProjectSettings.GetSetting("rendering/driver/threads/thread_model");
 
-        Internal.State.Instance = new(mainWindow, mainSubViewport, renderer switch
+        Internal.IRenderer internalRenderer;
+        try
         {
-            RendererType.Dummy => new Internal.DummyRenderer(),
-            RendererType.Canvas => new Internal.CanvasRenderer(),
-            RendererType.RenderingDevice => threadModel == 2 ? new Internal.RdRendererThreadSafe() : new Internal.RdRenderer(),
-            _ => throw new ArgumentException("Invalid renderer", nameof(renderer))
-        });
+            internalRenderer = renderer switch
+            {
+                RendererType.Dummy => new Internal.DummyRenderer(),
+                RendererType.Canvas => new Internal.CanvasRenderer(),
+                RendererType.RenderingDevice => threadModel == 2 ? new Internal.RdRendererThreadSafe() : new Internal.RdRenderer(),
+                _ => throw new ArgumentException("Invalid renderer", nameof(renderer))
+            };
+        }
+        catch (Exception e)
+        {
+            if (renderer == RendererType.RenderingDevice)
+            {
+                GD.PushWarning($"imgui-godot: falling back to Canvas renderer ({e.Message})");
+                internalRenderer = new Internal.CanvasRenderer();
+            }
+            else
+            {
+                GD.PushError("imgui-godot: failed to init renderer");
+                internalRenderer = new Internal.DummyRenderer();
+            }
+        }
+
+        Internal.State.Instance = new(mainWindow, mainSubViewport, internalRenderer);
         Internal.State.Instance.Renderer.InitViewport(mainSubViewport);
     }
 

addons/imgui-godot/ImGuiGodot/Internal/CanvasRenderer.cs

@@ -17,7 +17,7 @@ private sealed class ViewportData
     private readonly Dictionary<Rid, List<Rid>> _canvasItemPools = new();
     private readonly Dictionary<Rid, ViewportData> _vpData = new();
 
-    public string Name => "imgui_impl_godot4_canvas";
+    public string Name => "godot4_net_canvas";
 
     public void Init(ImGuiIOPtr io)
     {

addons/imgui-godot/ImGuiGodot/Internal/DummyRenderer.cs

@@ -5,7 +5,7 @@ namespace ImGuiGodot.Internal;
 
 internal sealed class DummyRenderer : IRenderer
 {
-    public string Name => "imgui_impl_godot4_dummy";
+    public string Name => "godot4_net_dummy";
 
     public void Init(ImGuiIOPtr io)
     {

addons/imgui-godot/ImGuiGodot/Internal/RdRenderer.cs

@@ -7,6 +7,13 @@
 
 namespace ImGuiGodot.Internal;
 
+internal sealed class RdRendererException : ApplicationException
+{
+    public RdRendererException(string message) : base(message)
+    {
+    }
+}
+
 internal class RdRenderer : IRenderer
 {
     protected readonly RenderingDevice RD;
@@ -39,21 +46,21 @@ internal class RdRenderer : IRenderer
     private readonly long[] _vtxOffsets = new long[3];
     private readonly Godot.Collections.Array<RDUniform> _uniformArray = new();
 
-    public string Name => "imgui_impl_godot4_rd";
+    public string Name => "godot4_net_rd";
 
     public RdRenderer()
     {
         RD = RenderingServer.GetRenderingDevice();
         if (RD is null)
-        {
-            throw new PlatformNotSupportedException("failed to get RenderingDevice");
-        }
+            throw new RdRendererException("failed to get RenderingDevice");
 
         // set up everything to match the official Vulkan backend as closely as possible
 
         // compiling from source takes ~400ms, so we use a SPIR-V resource
         using var spirv = ResourceLoader.Load<RDShaderSpirV>("res://addons/imgui-godot/data/ImGuiShaderSPIRV.tres");
         _shader = RD.ShaderCreateFromSpirV(spirv);
+        if (!_shader.IsValid)
+            throw new RdRendererException("failed to create shader");
 
 #if IMGUI_GODOT_DEV
 #pragma warning disable CA2201
@@ -62,7 +69,7 @@ public RdRenderer()
             SourceFragment = _fragmentShaderSource,
             SourceVertex = _vertexShaderSource,
         };
-        using var freshSpirv = RD.ShaderCompileSpirvFromSource(src);
+        using var freshSpirv = RD.ShaderCompileSpirVFromSource(src);
         if (!System.Linq.Enumerable.SequenceEqual(spirv.BytecodeFragment, freshSpirv.BytecodeFragment))
             throw new Exception("fragment bytecode mismatch");
         if (!System.Linq.Enumerable.SequenceEqual(spirv.BytecodeVertex, freshSpirv.BytecodeVertex))
@@ -137,6 +144,9 @@ public RdRenderer()
             new RDPipelineDepthStencilState(),
             blendData);
 
+        if (!_pipeline.IsValid)
+            throw new RdRendererException("failed to create pipeline");
+
         // sampler used for all textures
         using var samplerState = new RDSamplerState
         {
@@ -148,6 +158,8 @@ public RdRenderer()
             RepeatW = RenderingDevice.SamplerRepeatMode.Repeat
         };
         _sampler = RD.SamplerCreate(samplerState);
+        if (!_sampler.IsValid)
+            throw new RdRendererException("failed to create sampler");
 
         _srcBuffers.Resize(3);
         _uniformArray.Resize(1);

addons/imgui-godot/ImGuiGodot/Internal/RdRendererThreadSafe.cs

@@ -64,7 +64,7 @@ public void Dispose()
 
 internal sealed class RdRendererThreadSafe : RdRenderer, IRenderer
 {
-    public new string Name => "imgui_impl_godot4_rd_mt";
+    public new string Name => "godot4_net_rd_mt";
 
     private readonly object _sharedDataLock = new();
     private SharedList? _dataToDraw;

addons/imgui-godot/ImGuiGodot/Internal/State.cs

@@ -18,7 +18,7 @@ internal interface IRenderer
 
 internal sealed class State : IDisposable
 {
-    private static readonly IntPtr _backendName = Marshal.StringToCoTaskMemAnsi("imgui_impl_godot4_net");
+    private static readonly IntPtr _backendName = Marshal.StringToCoTaskMemAnsi("godot4_net");
     private static IntPtr _rendererName = IntPtr.Zero;
     private IntPtr _iniFilenameBuffer = IntPtr.Zero;