From 0415da9d29eb7ec7db86ca170f292d4d4a64b3d0 Mon Sep 17 00:00:00 2001
From: Gillibald <b.stebner@outlook.de>
Date: Wed, 28 Sep 2022 03:10:33 -0700
Subject: [PATCH] Emscripten interop sample

---
 src/Web/Avalonia.Web.Sample/Program.cs       |  2 ++
 src/Web/Avalonia.Web/Avalonia.Web.targets    |  1 +
 src/Web/Avalonia.Web/Interop/Emscripten.cs   | 31 ++++++++++++++++++++
 src/Web/Avalonia.Web/Interop/libEmscripten.c |  9 ++++++
 4 files changed, 43 insertions(+)
 create mode 100644 src/Web/Avalonia.Web/Interop/Emscripten.cs
 create mode 100644 src/Web/Avalonia.Web/Interop/libEmscripten.c

diff --git a/src/Web/Avalonia.Web.Sample/Program.cs b/src/Web/Avalonia.Web.Sample/Program.cs
index 233f95852f..2570aa2d58 100644
--- a/src/Web/Avalonia.Web.Sample/Program.cs
+++ b/src/Web/Avalonia.Web.Sample/Program.cs
@@ -6,6 +6,8 @@ internal partial class Program
 {
     private static void Main(string[] args)
     {
+        Emscripten.Log(EM_LOG.ERROR, "MyError");
+
         BuildAvaloniaApp().SetupBrowserApp("out");
     }
 
diff --git a/src/Web/Avalonia.Web/Avalonia.Web.targets b/src/Web/Avalonia.Web/Avalonia.Web.targets
index d1bec2aa93..537d746ab9 100644
--- a/src/Web/Avalonia.Web/Avalonia.Web.targets
+++ b/src/Web/Avalonia.Web/Avalonia.Web.targets
@@ -1,5 +1,6 @@
 <Project>
   <ItemGroup>
+    <NativeFileReference Include="$(MSBuildThisFileDirectory)/Interop/libEmscripten.c" />  
     <WasmExtraFilesToDeploy Include="$(MSBuildThisFileDirectory)/wwwroot/**/*.*" />
     <NativeFileReference Include="$(HarfBuzzSharpStaticLibraryPath)\3.1.7\libHarfBuzzSharp.a" />
     <NativeFileReference Include="$(SkiaSharpStaticLibraryPath)\3.1.7\libSkiaSharp.a" />
diff --git a/src/Web/Avalonia.Web/Interop/Emscripten.cs b/src/Web/Avalonia.Web/Interop/Emscripten.cs
new file mode 100644
index 0000000000..bfb42fa356
--- /dev/null
+++ b/src/Web/Avalonia.Web/Interop/Emscripten.cs
@@ -0,0 +1,31 @@
+using System;
+using System.Runtime.InteropServices;
+
+namespace Avalonia.Web
+{
+    public static partial class Emscripten
+    {
+        const string Prefix = "av_";
+        const string Library = "libEmscripten";
+
+        [LibraryImport(Library, EntryPoint = Prefix + "log", StringMarshalling = StringMarshalling.Utf8)]
+        public static partial void Log(EM_LOG flags, string format);
+
+        [LibraryImport(Library, EntryPoint = Prefix + "debugger")]
+        public static partial void Debugger();
+    }
+
+    [Flags]
+    public enum EM_LOG : int
+    {
+        CONSOLE = 1,
+        WARN = 2,
+        ERROR = 4,
+        C_STACK = 8,
+        JS_STACK = 16,
+        NO_PATHS = 64,
+        FUNC_PARAMS = 128,
+        DEBUG = 256,
+        INFO = 512,
+    }
+}
diff --git a/src/Web/Avalonia.Web/Interop/libEmscripten.c b/src/Web/Avalonia.Web/Interop/libEmscripten.c
new file mode 100644
index 0000000000..708be1abc8
--- /dev/null
+++ b/src/Web/Avalonia.Web/Interop/libEmscripten.c
@@ -0,0 +1,9 @@
+#include <emscripten.h>
+
+void av_log(int flags, const char* format) {
+    emscripten_log(flags, format);
+}
+
+void av_debugger() {
+    emscripten_debugger();
+}