Now using GLKView and CADisplayLink

src/Skia/Perspex.Skia.iOS.TestApp/MainView.cs

@@ -1,7 +1,9 @@
 using System;
+using System.Diagnostics;
 using System.Drawing;
 using CoreAnimation;
 using CoreGraphics;
+using CoreMedia;
 using Foundation;
 using Perspex.Media;
 using Perspex.Platform;
@@ -10,54 +12,40 @@ using UIKit;
 namespace Perspex.Skia.iOS.TestApp
 {
     [Register("MainView")]
-    public class MainView : UIView
+    public class MainView : SkiaView
     {
-        CAEAGLLayer _layer = new CAEAGLLayer();
         private IRenderTarget _target;
-
+        FormattedText _text;
         public MainView()
-        {
-            Initialize();
-        }
-
-        public MainView(RectangleF bounds) : base(bounds)
-        {
-            Initialize();
-        }
-        
-
-        void Initialize()
         {
             AutoresizingMask = UIViewAutoresizing.All;
-            Layer.AddSublayer(_layer);
-            
             SkiaPlatform.Initialize();
             _target = PerspexLocator.Current.GetService<IPlatformRenderInterface>()
-                .CreateRenderer(new PlatformHandle(_layer.DangerousRetain().Handle, "Layer"));
+                .CreateRenderer(PerspexPlatformHandle);
+            UpdateText(0);
         }
-
         double _radians = 0;
 
-        public override void TouchesMoved(NSSet touches, UIEvent evt)
+
+        void UpdateText(int fps)
         {
-            foreach (var touch in touches)
+            _text?.Dispose();
-            {
+            _text = new FormattedText("FPS: " + fps, "Arial", 15, FontStyle.Normal, TextAlignment.Left,
-                var loc = ((UITouch) touch).LocationInView(this);
+                FontWeight.Normal);
-                _radians = (loc.X + loc.Y)/100;
-            }
-            SetNeedsDisplay();
-            base.TouchesMoved(touches, evt);
         }
 
-        public override void Draw(CGRect rect)
+        double _lastFps;
+        int _frames;
+        Stopwatch St = Stopwatch.StartNew();
+        protected override void Draw()
         {
-            _layer.Bounds = new CGRect(0, 0, Bounds.Width, Bounds.Height);
+            _radians += 0.02;
             var scale = UIScreen.MainScreen.Scale;
             int width = (int) (Bounds.Width*scale), height = (int) (Bounds.Height*scale);
             using (var ctx = _target.CreateDrawingContext())
             {
                 ctx.FillRectangle(Brushes.Green, new Rect(0, 0, width, height));
-
+                ctx.DrawText(Brushes.Red, new Point(50, 50), _text);
                 var rc = new Rect(0, 0, width/3, height/3);
                 using (ctx.PushPostTransform(
                     Perspex.Matrix.CreateTranslation(-width/6, -width/6)*
@@ -74,7 +62,16 @@ namespace Perspex.Skia.iOS.TestApp
                     }, rc, 5);
                 }
             }
-
+            _frames++;
+            var now = St.Elapsed.TotalSeconds;
+            var elapsed = now - _lastFps;
+            if (elapsed > 1)
+            {
+                UpdateText((int) (_frames/elapsed));
+                _frames = 0;
+                _lastFps = now;
+            }
+            DrawOnNextFrame();
         }
     }
 }

src/Skia/Perspex.Skia.iOS/Perspex.Skia.iOS.csproj

@@ -37,6 +37,7 @@
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="iOSMethodTable.cs" />
+    <Compile Include="SkiaView.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
   </ItemGroup>
   <ItemGroup>

src/Skia/Perspex.Skia.iOS/SkiaView.cs

@@ -0,0 +1,64 @@
+using System;
+using System.Collections.Generic;
+using System.Runtime.InteropServices;
+using System.Text;
+using CoreAnimation;
+using CoreGraphics;
+using Foundation;
+using GLKit;
+using ObjCRuntime;
+using OpenGLES;
+using Perspex.Platform;
+using UIKit;
+
+namespace Perspex.Skia.iOS
+{
+    public abstract class SkiaView : GLKView
+    {
+        [DllImport("__Internal")]
+        static extern IntPtr GetPerspexEAGLContext();
+
+        bool _drawQueued;
+        CADisplayLink _link;
+        static EAGLContext GetContext()
+        {
+            //Ensure initialization
+            MethodTable.Instance.SetOption((MethodTable.Option)0x10009999, IntPtr.Zero);
+            var ctx = GetPerspexEAGLContext();
+            var rv = Runtime.GetNSObject<EAGLContext>(ctx);
+            rv.DangerousRetain();
+            return rv;
+        }
+
+
+        protected SkiaView() : base(UIScreen.MainScreen.ApplicationFrame, GetContext())
+        {
+            (_link = CADisplayLink.Create(() => OnFrame())).AddToRunLoop(NSRunLoop.Main, NSRunLoop.NSDefaultRunLoopMode);
+        }
+        
+        protected void OnFrame()
+        {
+            if (_drawQueued)
+            {
+                _drawQueued = false;
+                Display();
+            }
+        }
+
+        protected void DrawOnNextFrame()
+        {
+            _drawQueued = true;
+        }
+
+        protected IPlatformHandle PerspexPlatformHandle { get; } 
+            = new PlatformHandle(IntPtr.Zero, "Null (iOS-specific)");
+            
+
+        protected abstract void Draw();
+
+        public override void Draw(CGRect rect)
+        {
+            Draw();
+        }
+    }
+}