Remove Quad-buffered from list of VR-modes if we know it won't work.

src/d_main.cpp

@@ -2635,6 +2635,7 @@ void D_DoomMain (void)
 
 			V_Init2();
 			UpdateJoystickMenu(NULL);
+			UpdateVRModes();
 
 			v = Args->CheckValue ("-loadgame");
 			if (v)

src/menu/menu.h

@@ -363,4 +363,6 @@ DMenuItemBase * CreateListMenuItemPatch(double x, double y, int height, int hotk
 DMenuItemBase * CreateListMenuItemText(double x, double y, int height, int hotkey, const char *text, FFont *font, PalEntry color1, PalEntry color2, FName command, int param);
 DMenuItemBase * CreateOptionMenuItemCommand(const char *label, FName cmd, bool centered = false);
 
+void UpdateVRModes(bool considerQuadBuffered=true);
+
 #endif

src/menu/menudef.cpp

@@ -1724,3 +1724,31 @@ fail:
 		}
 	}
 }
+
+
+#ifdef _WIN32
+EXTERN_CVAR(Bool, vr_enable_quadbuffered)
+#endif
+
+void UpdateVRModes(bool considerQuadBuffered)
+{
+	FOptionValues ** pVRModes = OptionValues.CheckKey("VRMode");
+	if (pVRModes == nullptr) return;
+
+	TArray<FOptionValues::Pair> & vals = (*pVRModes)->mValues;
+	TArray<FOptionValues::Pair> filteredValues;
+	int cnt = vals.Size();
+	for (int i = 0; i < cnt; ++i) {
+		auto const & mode = vals[i];
+		if (mode.Value == 7) {  // Quad-buffered stereo
+#ifdef _WIN32
+			if (!vr_enable_quadbuffered) continue;
+#else
+			continue
+#endif
+			if (!considerQuadBuffered) continue;  // Probably no compatible screen mode was found
+		}
+		filteredValues.Push(mode);
+	}
+	vals = filteredValues;
+}

src/rendering/gl/renderer/gl_stereo3d.cpp

@@ -34,6 +34,7 @@
 #include "gl/system/gl_framebuffer.h"
 #include "hwrenderer/postprocessing/hw_presentshader.h"
 #include "hwrenderer/postprocessing/hw_present3dRowshader.h"
+#include "menu/menu.h"
 
 EXTERN_CVAR(Int, vr_mode)
 EXTERN_CVAR(Float, vid_saturation)
@@ -283,6 +284,8 @@ bool FGLRenderer::QuadStereoCheckInitialRenderContextState()
 										   // Now check whether this context supports hardware stereo
 			glGetBooleanv(GL_STEREO, &supportsStereo);
 			bQuadStereoSupported = supportsStereo && supportsBuffered;
+			if (! bQuadStereoSupported)
+				UpdateVRModes(false);
 		}
 	}
 	return bQuadStereoSupported;

src/v_video.h

@@ -361,7 +361,6 @@ public:
 	float glslversion = 0;						// This is here so that the differences between old OpenGL and new OpenGL/Vulkan can be handled by platform independent code.
 	int instack[2] = { 0,0 };					// this is globally maintained state for portal recursion avoidance.
 	int stencilValue = 0;						// Global stencil test value
-	bool enable_quadbuffered = false;			// Quad-buffered stereo available?
 	unsigned int uniformblockalignment = 256;	// Hardware dependent uniform buffer alignment.
 	unsigned int maxuniformblock = 65536;
 	const char *gl_vendorstring;				// On OpenGL (not Vulkan) we have to account for some issues with Intel.

src/win32/gl_sysfb.cpp

@@ -56,14 +56,6 @@ extern HWND			Window;
 
 PFNWGLSWAPINTERVALEXTPROC myWglSwapIntervalExtProc;
 
-// For broadest GL compatibility, require user to explicitly enable quad-buffered stereo mode.
-// Setting vr_enable_quadbuffered_stereo does not automatically invoke quad-buffered stereo,
-// but makes it possible for subsequent "vr_mode 7" to invoke quad-buffered stereo
-CUSTOM_CVAR(Bool, vr_enable_quadbuffered, false, CVAR_ARCHIVE | CVAR_GLOBALCONFIG | CVAR_NOINITCALL)
-{
-	Printf("You must restart " GAMENAME " to switch quad stereo mode\n");
-}
-
 //==========================================================================
 //
 // Windows framebuffer
@@ -111,7 +103,6 @@ SystemGLFrameBuffer::SystemGLFrameBuffer(void *hMonitor, bool fullscreen) : Syst
 		}
 	}
 	ReleaseDC(Window, hDC);
-    enable_quadbuffered = vr_enable_quadbuffered;
 }
 
 //==========================================================================

src/win32/win32basevideo.cpp

@@ -55,8 +55,6 @@
 
 CVAR(Int, vid_adapter, 1, CVAR_ARCHIVE | CVAR_GLOBALCONFIG)
 
-EXTERN_CVAR(Bool, vr_enable_quadbuffered)
-
 //==========================================================================
 //
 // 

src/win32/win32glvideo.cpp

@@ -54,7 +54,6 @@
 #include "gl/system/gl_framebuffer.h"
 
 EXTERN_CVAR(Int, vid_adapter)
-EXTERN_CVAR(Bool, vr_enable_quadbuffered)
 EXTERN_CVAR(Bool, vid_hdr)
 
 CUSTOM_CVAR(Bool, gl_debug, false, CVAR_ARCHIVE | CVAR_GLOBALCONFIG | CVAR_NOINITCALL)
@@ -62,6 +61,14 @@ CUSTOM_CVAR(Bool, gl_debug, false, CVAR_ARCHIVE | CVAR_GLOBALCONFIG | CVAR_NOINI
 	Printf("This won't take effect until " GAMENAME " is restarted.\n");
 }
 
+// For broadest GL compatibility, require user to explicitly enable quad-buffered stereo mode.
+// Setting vr_enable_quadbuffered_stereo does not automatically invoke quad-buffered stereo,
+// but makes it possible for subsequent "vr_mode 7" to invoke quad-buffered stereo
+CUSTOM_CVAR(Bool, vr_enable_quadbuffered, false, CVAR_ARCHIVE | CVAR_GLOBALCONFIG | CVAR_NOINITCALL)
+{
+	Printf("You must restart " GAMENAME " to switch quad stereo mode\n");
+}
+
 extern bool vid_hdr_active;
 
 // these get used before GLEW is initialized so we have to use separate pointers with different names