get hydra successfully rendering on metal.

Signed-off-by: furby™ <[email protected]>

Sources/HgiMetal/include/HgiMetal/texture.h

@@ -9,6 +9,8 @@
 
 #include <Metal/Metal.h>
 
+#include "Arch/swiftInterop.h"
+
 #include "Hgi/texture.h"
 #include "HgiMetal/api.h"
 #include "pxr/pxrns.h"
@@ -59,7 +61,7 @@ class HgiMetalTexture final : public HgiTexture {
   HgiMetalTexture(const HgiMetalTexture &) = delete;
 
   id<MTLTexture> _textureId;
-};
+} SWIFT_IMMORTAL_REFERENCE;
 
 PXR_NAMESPACE_CLOSE_SCOPE
 

Sources/UsdView/Hydra/Hydra+RenderEngine.swift

@@ -41,6 +41,9 @@ public enum Hydra
         sceneDelegateId: Sdf.Path.absoluteRootPath(),
         driver: driver
       )
+
+      engine.setEnablePresentation(false)
+      engine.setRenderer(aov: .color)
     }
 
     public func render(at timeCode: Double, viewSize: CGSize) -> Pixar.HgiTextureHandle

Sources/UsdView/Hydra/Hydra+View.swift

@@ -33,11 +33,11 @@ public extension Hydra
 
 public extension Hydra.Viewport
 {
-  init(engine: Hydra.RenderEngine, rgba: (Double, Double, Double, Double))
+  init(engine: Hydra.RenderEngine)
   {
     #if canImport(Metal) && !os(visionOS)
       let renderer = Hydra.MTLRenderer(device: engine.hydraDevice, hydra: engine)
-      self.init(hydra: engine, renderer: renderer, rgba: rgba)
+      self.init(hydra: engine, renderer: renderer)
     #endif // canImport(Metal) && !os(visionOS)
   }
 }

Sources/UsdView/Hydra/MTL/Hydra+MTLRenderer.swift

@@ -24,7 +24,7 @@ import PixarUSD
       private var hydra: Hydra.RenderEngine?
       private var pipelineState: MTLRenderPipelineState?
 
-      private var inFlightSemaphore = DispatchSemaphore(value: 1)
+      private var inFlightSemaphore = DispatchSemaphore(value: 3)
 
       convenience init(device: MTLDevice, hydra: Hydra.RenderEngine)
       {
@@ -87,6 +87,11 @@ import PixarUSD
 
       public func draw(in view: MTKView)
       {
+        view.drawableSize = CGSize(
+          width: (view.frame.size.width > 0) ? view.frame.size.width : 400, 
+          height: (view.frame.size.height > 0) ? view.frame.size.height : 300
+        )
+
         drawFrame(in: view, timeCode: 0.0)
       }
 
@@ -109,7 +114,7 @@ import PixarUSD
         let viewSize = view.drawableSize
         guard
           let hgiTexture = hydra?.render(at: timeCode, viewSize: viewSize),
-          let metalTexture = hgiTexture.GetId() as? MTLTexture,
+          let metalTexture = getMetalTexture(from: hgiTexture),
           let commandBuffer = hgi.pointee.GetPrimaryCommandBuffer()
         else { Msg.logger.error("HYDRA: Failed to draw the scene."); return false }
 
@@ -154,6 +159,24 @@ import PixarUSD
           commandBuffer.present(drawable)
         }
       }
+
+      public func getMetalTexture(from hgiTexture: Pixar.HgiTextureHandle) -> MTLTexture?
+      {
+        // get the hgi texture handle.
+        guard let hgiTex = hgiTexture.Get()
+        else { Msg.logger.error("HYDRA: Failed to retrieve the hgi texture."); return nil }
+
+        // get the raw pointer from the hgi handle.
+        let rawPtr = UnsafeRawPointer(hgiTex)
+
+        // get the hgi texture from the raw pointer.
+        let texPtr: Pixar.HgiMetalTexture = Unmanaged.fromOpaque(rawPtr).takeUnretainedValue()
+
+        // get the metal texture from the hgi texture.
+        let metalTexture = texPtr.GetTextureId()
+
+        return metalTexture
+      }
     }
   }
 #endif // canImport(Metal) && !os(visionOS)

Sources/UsdView/Hydra/MTL/Hydra+MTLView.swift

@@ -38,48 +38,57 @@ import PixarUSD
         private let device: MTLDevice!
         private let renderer: MTLRenderer!
 
-        var rgba: (Double, Double, Double, Double)
-
-        public init(hydra: Hydra.RenderEngine, renderer: MTLRenderer, rgba: (Double, Double, Double, Double))
+        public init(hydra: Hydra.RenderEngine, renderer: MTLRenderer)
         {
           self.hydra = hydra
-          self.device = hydra.hydraDevice
+          device = hydra.hydraDevice
           self.renderer = renderer
-          self.rgba = rgba
         }
 
         public func makeCoordinator() -> Coordinator
         {
-          Coordinator()
+          let mtkView = MTKView()
+          mtkView.isPaused = false
+          mtkView.framebufferOnly = true
+          if let mode = CGDisplayCopyDisplayMode(CGMainDisplayID())
+          {
+            mtkView.preferredFramesPerSecond = Int(mode.refreshRate)
+          }
+          else
+          {
+            mtkView.preferredFramesPerSecond = 60
+          }
+          mtkView.drawableSize = mtkView.frame.size
+
+          return Coordinator(mtkView: mtkView)
         }
 
         public func makeNSView(context: Context) -> MTKView
         {
           let metalView = context.coordinator.metalView
+
           metalView.device = device
           metalView.delegate = renderer
-          metalView.clearColor = MTLClearColorMake(rgba.0, rgba.1, rgba.2, rgba.3)
-          metalView.apply(context.environment)
-
-          context.coordinator.setNeedsDisplayTrigger = context.environment.setNeedsDisplayTrigger
 
+          metalView.becomeFirstResponder()
           return metalView
         }
 
-        public func updateNSView(_ view: MTKView, context: Context)
+        public func updateNSView(_ view: MTKView, context _: Context)
         {
           renderer.draw(in: view)
         }
 
         public class Coordinator
         {
           private var cancellable: AnyCancellable?
-          public var metalView: MTKView = .init(frame: .zero)
+          public var metalView: MTKView
 
-          public init()
+          public init(mtkView: MTKView)
           {
             cancellable = nil
             setNeedsDisplayTrigger = nil
+            metalView = mtkView
           }
 
           public var setNeedsDisplayTrigger: SetNeedsDisplayTrigger?

Sources/UsdView/UsdView.swift

@@ -39,10 +39,6 @@ struct UsdView: PixarApp
   /// the hydra rendering engine.
   let engine: Hydra.RenderEngine
 
-  /// give it a color spectrum...
-  @State var rgba = (0.1, 0.1, 0.1, 1.0)
-  @State var hue = 0.0
-
   public init()
   {
     // register all usd plugins & resources.
@@ -61,15 +57,7 @@ struct UsdView: PixarApp
   {
     WindowGroup("UsdView", id: "usdview")
     {
-      VStack
-      {
-        Hydra.Viewport(engine: engine, rgba: rgba)
-          .ignoresSafeArea()
-      }
-      .onAppear
-      {
-        startColorAnimation()
-      }
+      Hydra.Viewport(engine: engine)
     }
   }
 }

Sources/UsdView/Utils/ShadingUtils.swift

@@ -62,34 +62,3 @@ public func matDef(_ stage: UsdStageRefPtr, color: ShadeColor = ShadeColor.white
 
   return material
 }
-
-#if canImport(SwiftUI)
-  import SwiftUI
-
-  extension UsdView
-  {
-    func startColorAnimation()
-    {
-      Timer.scheduledTimer(withTimeInterval: 0.03, repeats: true)
-      { _ in
-        hue += 0.01
-        if hue > 1.0 { hue = 0.0 }
-        rgba = hueToRGBA(hue: hue)
-      }
-    }
-
-    func hueToRGBA(hue: Double) -> (Double, Double, Double, Double)
-    {
-      let color = Color(hue: hue, saturation: 1.0, brightness: 1.0)
-      var red: Double = 0, green: Double = 0, blue: Double = 0, alpha: Double = 0
-      if let components = color.cgColor?.components, components.count >= 3
-      {
-        red = components[0]
-        green = components[1]
-        blue = components[2]
-        alpha = Double(color.cgColor?.alpha ?? 1.0)
-      }
-      return (red, green, blue, alpha)
-    }
-  }
-#endif // canImport(SwiftUI)