Merge pull request #1 from frenzibyte/fix-metal-ios

Work around mono-level crash on iOS with interpreter

Author: peppy

src/Veldrid.MetalBindings/MTLBlitCommandEncoder.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Runtime.InteropServices;
 using static Veldrid.MetalBindings.ObjectiveCRuntime;
 
 namespace Veldrid.MetalBindings
@@ -29,9 +30,9 @@ public void copyFromBuffer(
             UIntPtr destinationSlice,
             UIntPtr destinationLevel,
             MTLOrigin destinationOrigin)
-            => objc_msgSend(
+        {
+            copyFromBuffer(
                 NativePtr,
-                sel_copyFromBuffer1,
                 sourceBuffer.NativePtr,
                 sourceOffset,
                 sourceBytesPerRow,
@@ -40,7 +41,25 @@ public void copyFromBuffer(
                 destinationTexture.NativePtr,
                 destinationSlice,
                 destinationLevel,
-                destinationOrigin);
+                destinationOrigin.x,
+                destinationOrigin.y,
+                destinationOrigin.z);
+        }
+
+        [DllImport("@rpath/metal_mono_workaround.framework/metal_mono_workaround")]
+        private static extern void copyFromBuffer(
+            IntPtr encoder,
+            IntPtr sourceBuffer,
+            UIntPtr sourceOffset,
+            UIntPtr sourceBytesPerRow,
+            UIntPtr sourceBytesPerImage,
+            MTLSize sourceSize,
+            IntPtr destinationTexture,
+            UIntPtr destinationSlice,
+            UIntPtr destinationLevel,
+            UIntPtr destinationOriginX,
+            UIntPtr destinationOriginY,
+            UIntPtr destinationOriginZ);
 
         public void copyTextureToBuffer(
             MTLTexture sourceTexture,
@@ -106,4 +125,4 @@ public void copyFromTexture(
         private static readonly Selector sel_synchronizeResource = "synchronizeResource:";
         private static readonly Selector sel_endEncoding = "endEncoding";
     }
-}
+}

src/Veldrid.MetalBindings/metal-mono-workaround/README.md

@@ -0,0 +1,12 @@
+# Metal Mono Workaround
+
+On iOS, simply defining a P/Invoke method for `MTLBlitCommandEncoder.copyFromBuffer` and invoking it blows up the application. To work around that, we're defining a method that has a different signature that's friendly with Mono, which redirects back to the original method.
+
+This library should be referenced by any project that uses Veldrid. 
+
+To generate the library, build the Xcode project on both iPhone and iPhone Simulator architectures, and execute the following to generate the XCFramework:
+```bash
+xcodebuild -create-xcframework -framework ./Release-iphoneos/metal_mono_workaround.framework -framework ./Release-iphonesimulator/metal_mono_workaround.framework -output metal-mono-workaround.xcframework
+```
+
+Afterwards, reference the XCFramework in your project and it should work correctly.