allow device change at any time

code/renderer/grp_main.cpp

@@ -193,7 +193,7 @@ void RenderPassStats::EndFrame(uint32_t cpu, uint32_t gpu)
 
 void GRP::Init()
 {
-	RHI::Init();
+	firstInit = RHI::Init();
 
 	if(firstInit)
 	{

code/renderer/grp_world.cpp

@@ -133,6 +133,11 @@ static void UpdateEntityData(bool& depthHack, int entityNum, double originalTime
 
 void World::Init()
 {
+	if(grp.firstInit)
+	{
+		fogDescriptorTable = RHI_MAKE_NULL_HANDLE();
+	}
+
 	{
 		TextureDesc desc("depth buffer", glConfig.vidWidth, glConfig.vidHeight);
 		desc.committedResource = true;

code/renderer/rhi_d3d12.cpp

@@ -2329,7 +2329,7 @@ namespace RHI
 		}
 	}
 
-	void Init()
+	bool Init()
 	{
 		Sys_V_Init();
 
@@ -2417,7 +2417,7 @@ namespace RHI
 
 			rhi.vsync = vsync;
 
-			return;
+			return false;
 		}
 
 		// @NOTE: we can't use memset because of the StaticPool members
@@ -2761,12 +2761,21 @@ namespace RHI
 		glInfo.depthFadeSupport = qfalse;
 
 		rhi.initialized = true;
+
+		return true;
 	}
 
 	void ShutDown(bool destroyWindow)
 	{
 #define DESTROY_POOL(Name, Func) DestroyPool(rhi.Name, &Func, !!destroyWindow);
 
+		if(!destroyWindow &&
+			r_gpuPreference->latchedString != NULL &&
+			Q_stricmp(r_gpuPreference->latchedString, r_gpuPreference->string) != 0)
+		{
+			destroyWindow = true;
+		}
+
 		if(rhi.frameBegun)
 		{
 			backEnd.renderFrame = qfalse;

code/renderer/rhi_local.h

@@ -676,7 +676,7 @@ namespace RHI
 		const ShaderMacro* macros = NULL;
 	};
 
-	void Init();
+	bool Init(); // true when a full init happened (the device was created)
 	void ShutDown(bool destroyWindow);
 
 	void BeginFrame();