Fall back to WARP if D3D11 hardware isn't present. Closes #121

* If hardware support for feature level 11 isn't present, fall back to
  the WARP software rasterizer. This will support everything needed, but
  it certainly won't run well.
* There are loud warnings - I added a debug message to the debug errors&
  warnings window so the status bar will indicate that, and it's in the
  title.
* At most once every 3 weeks there will also be a message box pop up
  when loading a log, to remind the user so that it isn't forgotten, as
  for obvious reasons this is not the intended use-case (hopefully once
  per 3 weeks isn't too often to be annoying).

renderdoc/api/replay/data_types.h

@@ -210,6 +210,7 @@ struct FetchDrawcall
 struct APIProperties
 {
 	APIPipelineStateType pipelineType;
+	bool32 degraded;
 };
 
 struct CounterDescription

renderdoc/core/image_viewer.cpp

@@ -39,6 +39,7 @@ class ImageViewer : public IReplayDriver
 			if(m_Proxy == NULL) RDCERR("Unexpectedly NULL proxy at creation of ImageViewer");
 
 			m_Props.pipelineType = ePipelineState_D3D11;
+			m_Props.degraded = false;
 			
 			FetchFrameRecord record;
 			record.frameInfo.fileOffset = 0;

renderdoc/core/replay_proxy.cpp

@@ -719,8 +719,9 @@ template<>
 void Serialiser::Serialise(const char *name, APIProperties &el)
 {
 	Serialise("", el.pipelineType);
+	Serialise("", el.degraded);
 
-	SIZE_CHECK(APIProperties, 4);
+	SIZE_CHECK(APIProperties, 8);
 }
 
 template<>

renderdoc/driver/d3d11/d3d11_replay.cpp

@@ -40,6 +40,7 @@ D3D11Replay::D3D11Replay()
 {
 	m_pDevice = NULL;
 	m_Proxy = false;
+	m_WARP = false;
 }
 
 void D3D11Replay::Shutdown()
@@ -340,6 +341,7 @@ APIProperties D3D11Replay::GetAPIProperties()
 	APIProperties ret;
 
 	ret.pipelineType = ePipelineState_D3D11;
+	ret.degraded = m_WARP;
 
 	return ret;
 }
@@ -1810,10 +1812,13 @@ ReplayCreateStatus D3D11_CreateReplayDevice(const char *logfile, IReplayDriver *
 	// check for feature level 11 support - passing NULL feature level array implicitly checks for 11_0 before others
 	hr = createDevice(NULL, D3D_DRIVER_TYPE_HARDWARE, NULL, 0, NULL, 0, D3D11_SDK_VERSION, NULL, NULL, NULL, &maxFeatureLevel, NULL);
 
+	bool warpFallback = false;
+
 	if(SUCCEEDED(hr) && maxFeatureLevel < D3D_FEATURE_LEVEL_11_0)
 	{
-		RDCERR("Couldn't create FEATURE_LEVEL_11_0 device - RenderDoc requires FEATURE_LEVEL_11_0 availability");
-		return eReplayCreate_APIHardwareUnsupported;
+		RDCWARN("Couldn't create FEATURE_LEVEL_11_0 device - RenderDoc requires FEATURE_LEVEL_11_0 availability - falling back to WARP rasterizer");
+		driverTypes[0] = driverType = D3D_DRIVER_TYPE_WARP;
+		warpFallback = true;
 	}
 
 	D3D11DebugManager::PreDeviceInitCounters();
@@ -1835,7 +1840,13 @@ ReplayCreateStatus D3D11_CreateReplayDevice(const char *logfile, IReplayDriver *
 			RDCLOG("Created device.");
 			D3D11Replay *replay = wrappedDev->GetReplay();
 
-			replay->SetProxy(logfile == NULL);
+			replay->SetProxy(logfile == NULL, warpFallback);
+			if(warpFallback)
+			{
+				wrappedDev->AddDebugMessage(eDbgCategory_Initialization, eDbgSeverity_High, eDbgSource_RuntimeWarning,
+					"Couldn't create FEATURE_LEVEL_11_0 device - RenderDoc requires FEATURE_LEVEL_11_0 availability - falling back to WARP rasterizer.\n" \
+					"Performance and usability will be significantly degraded.");
+			}
 
 			*driver = (IReplayDriver *)replay;
 			return eReplayCreate_Success;

renderdoc/driver/d3d11/d3d11_replay.h

@@ -36,7 +36,7 @@ class D3D11Replay : public IReplayDriver
 	public:
 		D3D11Replay();
 
-		void SetProxy(bool p) { m_Proxy = p; }
+		void SetProxy(bool p, bool warp) { m_Proxy = p; m_WARP = warp; }
 		bool IsRemoteProxy() { return m_Proxy; }
 
 		void Shutdown();
@@ -135,6 +135,7 @@ class D3D11Replay : public IReplayDriver
 	private:
 		D3D11PipelineState MakePipelineState();
 
+		bool m_WARP;
 		bool m_Proxy;
 
 		WrappedID3D11Device *m_pDevice;

renderdoc/driver/gl/gl_replay.cpp

@@ -86,6 +86,7 @@ APIProperties GLReplay::GetAPIProperties()
 	APIProperties ret;
 
 	ret.pipelineType = ePipelineState_OpenGL;
+	ret.degraded = false;
 
 	return ret;
 }

renderdocui/Code/Core.cs

@@ -512,6 +512,20 @@ namespace renderdocui.Code
 
             Thread.Sleep(20);
 
+            DateTime today = DateTime.Now;
+            DateTime compare = today.AddDays(-21);
+
+            if (compare.CompareTo(Config.DegradedLog_LastUpdate) >= 0 && m_APIProperties.degraded)
+            {
+                Config.DegradedLog_LastUpdate = today;
+
+                MessageBox.Show(String.Format("{0}\nThis log opened with degraded support - " +
+                                                "this could mean missing hardware support caused a fallback to software rendering.\n\n" +
+                                                "This warning will not appear every time this happens, " +
+                                                "check debug errors/warnings window for more details.", logFile),
+                                "Degraded support of log", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
+            }
+
             m_LogLoaded = true;
             progressThread = false;
 

renderdocui/Code/PersistantConfig.cs

@@ -95,6 +95,8 @@ namespace renderdocui.Code
         public bool CheckUpdate_UpdateAvailable = false;
         public DateTime CheckUpdate_LastUpdate = new DateTime(2012, 06, 27);
 
+        public DateTime DegradedLog_LastUpdate = new DateTime(2015, 01, 01);
+
         public bool AllowGlobalHook = false;
 
         public void SetupFormatter()

renderdocui/Interop/FetchInfo.cs

@@ -487,6 +487,7 @@ namespace renderdoc
     public class APIProperties
     {
         public APIPipelineStateType pipelineType;
+        public bool degraded;
     };
 
     [StructLayout(LayoutKind.Sequential)]

renderdocui/Windows/MainWindow.cs

@@ -594,6 +594,8 @@ namespace renderdocui.Windows
             if (m_Core != null && m_Core.LogLoaded)
             {
                 prefix = Path.GetFileName(m_Core.LogFileName);
+                if (m_Core.APIProps.degraded)
+                    prefix += " !DEGRADED PERFORMANCE!";
                 if (m_RemoteReplay.Length > 0)
                     prefix += String.Format(" (Remote replay on {0})", m_RemoteReplay);
                 prefix += " - ";