From daed903b642503c46d5fdb9f9ddc559874647b4b Mon Sep 17 00:00:00 2001
From: baldurk <baldurk@baldurk.org>
Date: Thu, 3 Jan 2019 11:51:40 +0000
Subject: [PATCH] Add support for wglShareLists. Closes #1224

* We can't feasibly support calling wglShareLists after wglMakeCurrent because
  we must do work and create objects in wglMakeCurrent. If this situation
  happens we pretend that wglShareLists failed and print an error.
---
 renderdoc/driver/gl/gl_driver.cpp        | 27 +++++++++++++++++++++---
 renderdoc/driver/gl/gl_driver.h          |  1 +
 renderdoc/driver/gl/wgl_dispatch_table.h |  2 ++
 renderdoc/driver/gl/wgl_hooks.cpp        | 18 ++++++++++++++++
 4 files changed, 45 insertions(+), 3 deletions(-)

diff --git a/renderdoc/driver/gl/gl_driver.cpp b/renderdoc/driver/gl/gl_driver.cpp
index d6cb05cea..f3b17cfc9 100644
--- a/renderdoc/driver/gl/gl_driver.cpp
+++ b/renderdoc/driver/gl/gl_driver.cpp
@@ -991,6 +991,24 @@ void WrappedOpenGL::CreateContext(GLWindowingData winData, void *shareContext,
   m_ScratchSerialiser.SetChunkMetadataRecording(flags);
 }
 
+bool WrappedOpenGL::ForceSharedObjects(void *oldContext, void *newContext)
+{
+  ContextData &olddata = m_ContextData[oldContext];
+  ContextData &newdata = m_ContextData[newContext];
+
+  RDCLOG("Forcibly sharing %p with %p", newContext, oldContext);
+
+  if(newdata.built)
+  {
+    RDCERR("wglShareLists called after wglMakeCurrent - this is not supported and will break.");
+    return false;
+  }
+
+  newdata.shareGroup = olddata.shareGroup;
+
+  return true;
+}
+
 void WrappedOpenGL::RegisterReplayContext(GLWindowingData winData, void *shareContext, bool core,
                                           bool attribsCreate)
 {
@@ -1656,9 +1674,12 @@ void WrappedOpenGL::SwapBuffers(void *windowHandle)
     ctxdata.AssociateWindow(this, windowHandle);
   }
 
-  // do this as late as possible to avoid creating objects on contexts
-  // that might be shared later (wglShareLists requires contexts to be
-  // pristine, so can't create this from wglMakeCurrent)
+  // we used to do this here so it was as late as possible to avoid creating objects on contexts
+  // that might be shared later. wglShareLists requires contexts to have no objects and can be
+  // called after wglMakeCurrent. However we also need other objects like client-memory buffers and
+  // vendor checks inside makecurrent that it is not feasible to defer until later, since there's no
+  // other sync point after wglMakeCurrent before we'll need the information. So we don't support
+  // calling wglShareLists after wglMakeCurrent.
   if(!ctxdata.ready)
     ctxdata.CreateDebugData();
 
diff --git a/renderdoc/driver/gl/gl_driver.h b/renderdoc/driver/gl/gl_driver.h
index cf9c524b5..68d27bd12 100644
--- a/renderdoc/driver/gl/gl_driver.h
+++ b/renderdoc/driver/gl/gl_driver.h
@@ -541,6 +541,7 @@ public:
     return m_ContextData[winData.ctx].initParams;
   }
   void ActivateContext(GLWindowingData winData);
+  bool ForceSharedObjects(void *oldContext, void *newContext);
   void SwapBuffers(void *windowHandle);
   void HandleVRFrameMarkers(const GLchar *buf, GLsizei length);
   bool UsesVRFrameMarkers() { return m_UsesVRMarkers; }
diff --git a/renderdoc/driver/gl/wgl_dispatch_table.h b/renderdoc/driver/gl/wgl_dispatch_table.h
index 95f100aa1..a870baeeb 100644
--- a/renderdoc/driver/gl/wgl_dispatch_table.h
+++ b/renderdoc/driver/gl/wgl_dispatch_table.h
@@ -29,6 +29,7 @@
 // exported wgl functions
 typedef HGLRC(WINAPI *PFN_wglCreateContext)(HDC);
 typedef BOOL(WINAPI *PFN_wglDeleteContext)(HGLRC);
+typedef BOOL(WINAPI *PFN_wglShareLists)(HGLRC, HGLRC);
 typedef HGLRC(WINAPI *PFN_wglCreateLayerContext)(HDC, int);
 typedef BOOL(WINAPI *PFN_wglMakeCurrent)(HDC, HGLRC);
 typedef PROC(WINAPI *PFN_wglGetProcAddress)(const char *);
@@ -70,6 +71,7 @@ typedef LONG(WINAPI *PFN_ChangeDisplaySettingsExW)(LPCWSTR, DEVMODEW *, HWND, DW
   FUNC("opengl32.dll", wglMakeCurrent);         \
   FUNC("opengl32.dll", wglGetProcAddress);      \
   FUNC("opengl32.dll", wglSwapBuffers);         \
+  FUNC("opengl32.dll", wglShareLists);          \
   FUNC("opengl32.dll", wglSwapLayerBuffers);    \
   FUNC("opengl32.dll", wglSwapMultipleBuffers); \
   FUNC("", wglCreateContextAttribsARB);         \
diff --git a/renderdoc/driver/gl/wgl_hooks.cpp b/renderdoc/driver/gl/wgl_hooks.cpp
index 210ed5f2a..aa130d626 100644
--- a/renderdoc/driver/gl/wgl_hooks.cpp
+++ b/renderdoc/driver/gl/wgl_hooks.cpp
@@ -361,6 +361,24 @@ static HGLRC WINAPI wglCreateContextAttribsARB_hooked(HDC dc, HGLRC hShareContex
   return ret;
 }
 
+static BOOL WINAPI wglShareLists_hooked(HGLRC oldContext, HGLRC newContext)
+{
+  bool ret = WGL.wglShareLists(oldContext, newContext) == TRUE;
+
+  DWORD err = GetLastError();
+
+  if(ret)
+  {
+    SCOPED_LOCK(glLock);
+
+    ret &= wglhook.driver.ForceSharedObjects(oldContext, newContext);
+  }
+
+  SetLastError(err);
+
+  return ret ? TRUE : FALSE;
+}
+
 static BOOL WINAPI wglMakeCurrent_hooked(HDC dc, HGLRC rc)
 {
   BOOL ret = WGL.wglMakeCurrent(dc, rc);