From a564a27c1f4ecc3fada5b1c7f087003930ac828e Mon Sep 17 00:00:00 2001
From: Jeroen Bakker <jeroen@blender.org>
Date: Thu, 10 Apr 2025 08:50:52 +0200
Subject: [PATCH] Cleanup: OpenXR: Introduce a Direct3D base class.

For the Vulkan/OpenXR code will be shared with the OpenGL-Direct3D
bridge. This cleanup separates the OpenGL specifics in its own class.

Pull Request: https://projects.blender.org/blender/blender/pulls/137252
---
 intern/ghost/GHOST_Types.h                    |  2 +-
 intern/ghost/intern/GHOST_ContextD3D.hh       |  1 +
 intern/ghost/intern/GHOST_XrContext.cc        |  2 +-
 .../ghost/intern/GHOST_XrGraphicsBinding.cc   | 47 ++++++++++++-------
 .../blender/windowmanager/xr/intern/wm_xr.cc  |  2 +-
 5 files changed, 34 insertions(+), 20 deletions(-)

diff --git a/intern/ghost/GHOST_Types.h b/intern/ghost/GHOST_Types.h
index 337bdabc636..e1bea143827 100644
--- a/intern/ghost/GHOST_Types.h
+++ b/intern/ghost/GHOST_Types.h
@@ -897,7 +897,7 @@ typedef enum GHOST_TXrGraphicsBinding {
   GHOST_kXrGraphicsOpenGL,
   GHOST_kXrGraphicsVulkan,
 #  ifdef WIN32
-  GHOST_kXrGraphicsD3D11,
+  GHOST_kXrGraphicsOpenGLD3D11,
 #  endif
   /* For later */
   //  GHOST_kXrGraphicsVulkan,
diff --git a/intern/ghost/intern/GHOST_ContextD3D.hh b/intern/ghost/intern/GHOST_ContextD3D.hh
index af31c44ebe9..e6d02a428e4 100644
--- a/intern/ghost/intern/GHOST_ContextD3D.hh
+++ b/intern/ghost/intern/GHOST_ContextD3D.hh
@@ -19,6 +19,7 @@
 class GHOST_ContextD3D : public GHOST_Context {
   /* XR code needs low level graphics data to send to OpenXR. */
   friend class GHOST_XrGraphicsBindingD3D;
+  friend class GHOST_XrGraphicsBindingOpenGLD3D;
 
  public:
   GHOST_ContextD3D(bool stereoVisual, HWND hWnd);
diff --git a/intern/ghost/intern/GHOST_XrContext.cc b/intern/ghost/intern/GHOST_XrContext.cc
index afeaa7a6476..eb683b88b7f 100644
--- a/intern/ghost/intern/GHOST_XrContext.cc
+++ b/intern/ghost/intern/GHOST_XrContext.cc
@@ -394,7 +394,7 @@ static const char *openxr_ext_name_from_wm_gpu_binding(GHOST_TXrGraphicsBinding
 #endif
 
 #ifdef WIN32
-    case GHOST_kXrGraphicsD3D11:
+    case GHOST_kXrGraphicsOpenGLD3D11:
       return XR_KHR_D3D11_ENABLE_EXTENSION_NAME;
 #endif
     case GHOST_kXrGraphicsUnknown:
diff --git a/intern/ghost/intern/GHOST_XrGraphicsBinding.cc b/intern/ghost/intern/GHOST_XrGraphicsBinding.cc
index d74c0b4f338..c6b2767629e 100644
--- a/intern/ghost/intern/GHOST_XrGraphicsBinding.cc
+++ b/intern/ghost/intern/GHOST_XrGraphicsBinding.cc
@@ -333,16 +333,12 @@ static void ghost_format_to_dx_format(GHOST_TXrSwapchainFormat ghost_format,
 
 class GHOST_XrGraphicsBindingD3D : public GHOST_IXrGraphicsBinding {
  public:
-  GHOST_XrGraphicsBindingD3D(GHOST_Context &ghost_ctx)
-      : GHOST_IXrGraphicsBinding(), m_ghost_wgl_ctx(static_cast<GHOST_ContextWGL &>(ghost_ctx))
+  GHOST_XrGraphicsBindingD3D() : GHOST_IXrGraphicsBinding()
   {
     m_ghost_d3d_ctx = GHOST_SystemWin32::createOffscreenContextD3D();
   }
-  ~GHOST_XrGraphicsBindingD3D()
+  virtual ~GHOST_XrGraphicsBindingD3D()
   {
-    if (m_shared_resource) {
-      m_ghost_d3d_ctx->disposeSharedOpenGLResource(m_shared_resource);
-    }
     if (m_ghost_d3d_ctx) {
       GHOST_SystemWin32::disposeContextD3D(m_ghost_d3d_ctx);
     }
@@ -464,6 +460,32 @@ class GHOST_XrGraphicsBindingD3D : public GHOST_IXrGraphicsBinding {
     return base_images;
   }
 
+  bool needsUpsideDownDrawing(GHOST_Context &) const
+  {
+    return m_ghost_d3d_ctx->isUpsideDown();
+  }
+
+ protected:
+  /** Secondary DirectX 11 context used by OpenXR. */
+  GHOST_ContextD3D *m_ghost_d3d_ctx = nullptr;
+
+  std::list<std::vector<XrSwapchainImageD3D11KHR>> m_image_cache;
+};
+
+class GHOST_XrGraphicsBindingOpenGLD3D : public GHOST_XrGraphicsBindingD3D {
+ public:
+  GHOST_XrGraphicsBindingOpenGLD3D(GHOST_Context &ghost_ctx)
+      : GHOST_XrGraphicsBindingD3D(), m_ghost_wgl_ctx(static_cast<GHOST_ContextWGL &>(ghost_ctx))
+  {
+  }
+  ~GHOST_XrGraphicsBindingOpenGLD3D()
+  {
+    if (m_shared_resource) {
+      m_ghost_d3d_ctx->disposeSharedOpenGLResource(m_shared_resource);
+      m_shared_resource = nullptr;
+    }
+  }
+
   void submitToSwapchainImage(XrSwapchainImageBaseHeader &swapchain_image,
                               const GHOST_XrDrawViewInfo &draw_info) override
   {
@@ -504,20 +526,11 @@ class GHOST_XrGraphicsBindingD3D : public GHOST_IXrGraphicsBinding {
 #  endif
   }
 
-  bool needsUpsideDownDrawing(GHOST_Context &) const
-  {
-    return m_ghost_d3d_ctx->isUpsideDown();
-  }
-
  private:
   /** Primary OpenGL context for Blender to use for drawing. */
   GHOST_ContextWGL &m_ghost_wgl_ctx;
-  /** Secondary DirectX 11 context to share with OpenGL context. */
-  GHOST_ContextD3D *m_ghost_d3d_ctx = nullptr;
   /** Handle to shared resource object. */
   GHOST_SharedOpenGLResource *m_shared_resource = nullptr;
-
-  std::list<std::vector<XrSwapchainImageD3D11KHR>> m_image_cache;
 };
 #endif  // WIN32
 
@@ -532,8 +545,8 @@ std::unique_ptr<GHOST_IXrGraphicsBinding> GHOST_XrGraphicsBindingCreateFromType(
       return std::make_unique<GHOST_XrGraphicsBindingVulkan>();
 #endif
 #ifdef WIN32
-    case GHOST_kXrGraphicsD3D11:
-      return std::make_unique<GHOST_XrGraphicsBindingD3D>(context);
+    case GHOST_kXrGraphicsOpenGLD3D11:
+      return std::make_unique<GHOST_XrGraphicsBindingOpenGLD3D>(context);
 #endif
     default:
       return nullptr;
diff --git a/source/blender/windowmanager/xr/intern/wm_xr.cc b/source/blender/windowmanager/xr/intern/wm_xr.cc
index 180a61b5ce1..ed4dae933a8 100644
--- a/source/blender/windowmanager/xr/intern/wm_xr.cc
+++ b/source/blender/windowmanager/xr/intern/wm_xr.cc
@@ -71,7 +71,7 @@ bool wm_xr_init(wmWindowManager *wm)
       case GPU_BACKEND_OPENGL:
         gpu_bindings_candidates.append(GHOST_kXrGraphicsOpenGL);
 #  ifdef WIN32
-        gpu_bindings_candidates.append(GHOST_kXrGraphicsD3D11);
+        gpu_bindings_candidates.append(GHOST_kXrGraphicsOpenGLD3D11);
 #  endif
         break;
 #endif