Adding Metal renderer support (on iOS)

Author: krispypen

README.md

@@ -80,13 +80,9 @@ Be sure you have at least one scene added to your build.
 
    **iOS Platform**:
     1. This only works with Unity version >=2019.3 because uses Unity as a library!
-    2. Other Settings find the Rendering part, uncheck the `Auto   Graphics API` and select only `OpenGLES3`.
-    3. Depending on where you want to test or run your app, (simulator or physical device), you should select the appropriate SDK on `Target SDK`.
+    2. Depending on where you want to test or run your app, (simulator or physical device), you should select the appropriate SDK on `Target SDK`.
       <br />
 
-
-      
-
 <br />
 
 ### Add Unity Build Scripts and Export

scripts/Editor/XCodePostBuild.cs

@@ -79,6 +79,7 @@ private static void PatchUnityNativeCode(string pathToBuiltProject)
         EditUnityFrameworkH(Path.Combine(pathToBuiltProject, "UnityFramework/UnityFramework.h"));
         EditUnityAppControllerH(Path.Combine(pathToBuiltProject, "Classes/UnityAppController.h"));
         EditUnityAppControllerMM(Path.Combine(pathToBuiltProject, "Classes/UnityAppController.mm"));
+        EditUnityViewMM(Path.Combine(pathToBuiltProject, "Classes/UI/UnityView.mm"));
     }
 
 
@@ -265,6 +266,43 @@ private static void EditUnityAppControllerMM(string path)
         });
     }
 
+    /// <summary>
+    /// Edit 'UnityView.mm': fix the width and height needed for the Metal renderer
+    /// </summary>
+    private static void EditUnityViewMM(string path)
+    {
+        var inScope = false;
+
+        // Add frameworkWarmup method
+        EditCodeFile(path, line =>
+        {
+            inScope |= line.Contains("UnityGetRenderingResolution(&requestedW, &requestedH)");
+
+            if (inScope)
+            {
+                if (line.Trim() == "")
+                {
+                    inScope = false;
+
+                    return new string[]
+                    {
+                        "",
+                        "// Added by " + TouchedMarker,
+                        "        if (requestedW == 0) {",
+                        "            requestedW = _surfaceSize.width;",
+                        "        }",
+                        "        if (requestedH == 0) {",
+                        "            requestedH = _surfaceSize.height;",
+                        "        }",
+                        ""
+                    };
+                }
+            }
+
+            return new string[] { line };
+        });
+    }
+
     private static void EditCodeFile(string path, Func<string, IEnumerable<string>> lineHandler)
     {
         var bakPath = path + ".bak";