perf(Studio): Use custom-platform-control for SkiaSharp on macOS

Studio/CelesteStudio.GTK/SkiaDrawableHandler.cs

@@ -57,6 +57,17 @@ protected override bool OnDrawn(Context cr) {
 
             return false;
         }
+
+        protected override void Dispose(bool disposing) {
+            bitmap?.Dispose();
+            bitmap = null;
+
+            surface?.Dispose();
+            surface = null;
+
+            imageSurface?.Dispose();
+            imageSurface = null;
+        }
     }
 
     public bool CanFocus {

Studio/CelesteStudio.Mac/CelesteStudio.Mac.csproj

@@ -3,6 +3,8 @@
     <PropertyGroup>
         <OutputType>Exe</OutputType>
         <TargetFramework>net7.0</TargetFramework>
+        <LangVersion>latest</LangVersion>
+        <Nullable>enable</Nullable>
         <RuntimeIdentifiers>osx-x64;osx-arm64</RuntimeIdentifiers>
 
         <SupportedOSPlatformVersion>10.15</SupportedOSPlatformVersion>

Studio/CelesteStudio.Mac/Program.cs

@@ -1,5 +1,6 @@
 using System;
 using CelesteStudio.Communication;
+using CelesteStudio.Controls;
 using Eto.Forms;
 
 namespace CelesteStudio.Mac;
@@ -8,7 +9,10 @@ public static class Program {
     [STAThread]
     public static void Main(string[] args) {
         try {
-            new Application(Eto.Platforms.Mac64).Run(new Studio(args, _ => {}));
+            var platform = new Eto.Mac.Platform();
+            platform.Add<SkiaDrawable.IHandler>(() => new SkiaDrawableHandler());
+
+            new Application(platform).Run(new Studio(args, _ => {}));
         } catch (Exception ex) {
             Console.Error.WriteLine(ex);
             ErrorLog.Write(ex);

Studio/CelesteStudio.Mac/SkiaDrawableHandler.cs

@@ -0,0 +1,92 @@
+using CelesteStudio.Controls;
+using Eto.Mac.Forms;
+using MonoMac.AppKit;
+using MonoMac.CoreGraphics;
+using SkiaSharp;
+using System;
+using System.Runtime.InteropServices;
+
+namespace CelesteStudio.Mac;
+
+public class SkiaDrawableHandler : MacPanel<SkiaDrawableHandler.SkiaDrawableView, SkiaDrawable, SkiaDrawable.ICallback>, SkiaDrawable.IHandler {
+    public void Create() {
+        Enabled = true;
+        Control = new SkiaDrawableView(Widget);
+    }
+
+    public override NSView ContainerControl => Control;
+    public bool CanFocus {
+        get => true;
+        set { }
+    }
+
+    public class SkiaDrawableView(SkiaDrawable drawable) : MacPanelView {
+        private IntPtr bitmapData;
+        private int lastLength;
+
+        private SKSurface? surface;
+
+        private readonly CGColorSpace colorSpace = CGColorSpace.CreateDeviceRGB();
+        private CGDataProvider? dataProvider;
+        private CGImage? image;
+
+        public override void DrawRect(CGRect dirtyRect)
+        {
+            base.DrawRect(dirtyRect);
+
+            var bounds = new CGRect(drawable.DrawX, drawable.DrawY, drawable.DrawWidth, drawable.DrawHeight);
+            var info = new SKImageInfo((int)bounds.Width, (int)bounds.Height, SKColorType.Rgba8888, SKAlphaType.Premul);
+
+            // Allocate a memory block for the drawing process
+            int newLength = info.BytesSize;
+            if (lastLength != newLength)
+            {
+                lastLength = newLength;
+                if (bitmapData != IntPtr.Zero) {
+                    bitmapData = Marshal.ReAllocCoTaskMem(bitmapData, newLength);
+                } else {
+                    bitmapData = Marshal.AllocCoTaskMem(newLength);
+                }
+
+                surface?.Dispose();
+                surface = SKSurface.Create(info, bitmapData, info.RowBytes);
+
+                dataProvider?.Dispose();
+                dataProvider = new CGDataProvider(bitmapData, lastLength);
+
+                image?.Dispose();
+                image = new CGImage(
+                    info.Width, info.Height,
+                    8, info.BitsPerPixel, info.RowBytes,
+                    colorSpace, CGBitmapFlags.ByteOrder32Big | CGBitmapFlags.PremultipliedLast,
+                    dataProvider, null, false, CGColorRenderingIntent.Default);
+            }
+
+            using (new SKAutoCanvasRestore(surface!.Canvas, true)) {
+                drawable.Draw(surface);
+            }
+            surface.Canvas.Flush();
+
+            var ctx = NSGraphicsContext.CurrentContext.GraphicsPort;
+            ctx.DrawImage(bounds, image);
+        }
+
+        protected override void Dispose(bool disposing) {
+            Marshal.FreeCoTaskMem(bitmapData);
+
+            bitmapData = IntPtr.Zero;
+            lastLength = 0;
+
+            surface?.Dispose();
+            surface = null;
+
+            colorSpace.Dispose();
+
+            dataProvider?.Dispose();
+            dataProvider = null;
+
+            image?.Dispose();
+            image = null;
+        }
+    }
+}