Improve error messages when OpenGL video init fails

stepmania/src/RageDisplay.cpp

@@ -95,8 +95,7 @@ bool RageDisplay::SetVideoMode( VideoModeParams p )
 	if( this->TryVideoMode(p,bNeedReloadTextures) == "" )
 		return bNeedReloadTextures;
 
-	RageException::ThrowNonfatal( "SetVideoMode failed: %s.  Tried to fall back to other modes, but nothing worked.",
+	RageException::ThrowNonfatal( "SetVideoMode failed: %s", err.c_str() );
-			err.c_str() );
 }
 
 void RageDisplay::ProcessStatsOnFlip()

stepmania/src/RageDisplay_OGL.cpp

@@ -538,8 +538,10 @@ void RageDisplay_OGL::ResolutionChanged()
 CString RageDisplay_OGL::TryVideoMode( VideoModeParams p, bool &bNewDeviceOut )
 {
 //	LOG->Trace( "RageDisplay_OGL::SetVideoMode( %d, %d, %d, %d, %d, %d )", windowed, width, height, bpp, rate, vsync );
-	if( !wind->TryVideoMode( p, bNewDeviceOut ) )
+	CString err;
-		return "wind->TryVideoMode() failed";	// failed to set video mode XXX: error message
+	err = wind->TryVideoMode( p, bNewDeviceOut );
+	if( err != "" )
+		return err;	// failed to set video mode
 
 	if( bNewDeviceOut )
 	{

stepmania/src/arch/LowLevelWindow/LowLevelWindow.h

@@ -14,10 +14,10 @@ public:
 
 	virtual void *GetProcAddress(CString s) = 0;
 
-	// Return true if mode change was successful.
+	// Return "" if mode change was successful, otherwise an error message.
 	// bNewDeviceOut is set true if a new device was created and textures
 	// need to be reloaded.
-	virtual bool TryVideoMode( RageDisplay::VideoModeParams p, bool &bNewDeviceOut ) = 0;
+	virtual CString TryVideoMode( RageDisplay::VideoModeParams p, bool &bNewDeviceOut ) = 0;
 
 	virtual void SwapBuffers() = 0;
 	virtual void Update(float fDeltaTime) { }

stepmania/src/arch/LowLevelWindow/LowLevelWindow_SDL.cpp

@@ -32,7 +32,7 @@ void *LowLevelWindow_SDL::GetProcAddress(CString s)
 	return SDL_GL_GetProcAddress(s);
 }
 
-bool LowLevelWindow_SDL::TryVideoMode( RageDisplay::VideoModeParams p, bool &bNewDeviceOut )
+CString LowLevelWindow_SDL::TryVideoMode( RageDisplay::VideoModeParams p, bool &bNewDeviceOut )
 {
 	CurrentParams = p;
 
@@ -115,7 +115,7 @@ bool LowLevelWindow_SDL::TryVideoMode( RageDisplay::VideoModeParams p, bool &bNe
 	if(!screen)
 	{
 		LOG->Trace("SDL_SetVideoMode failed: %s", SDL_GetError());
-		return false;	// failed to set mode
+		return SDL_GetError();	// failed to set mode
 	}
 
 	bNewDeviceOut = true;	// always a new context because we're resetting SDL_Video
@@ -152,7 +152,7 @@ bool LowLevelWindow_SDL::TryVideoMode( RageDisplay::VideoModeParams p, bool &bNe
 			colorbits, r, g, b, a, depth, stencil);
 	}
 
-	return true;	// we set the video mode successfully
+	return "";	// we set the video mode successfully
 }
 
 void LowLevelWindow_SDL::SwapBuffers()

stepmania/src/arch/LowLevelWindow/LowLevelWindow_SDL.h

@@ -11,7 +11,7 @@ public:
 	LowLevelWindow_SDL();
 	~LowLevelWindow_SDL();
 	void *GetProcAddress(CString s);
-	bool TryVideoMode( RageDisplay::VideoModeParams p, bool &bNewDeviceOut );
+	CString TryVideoMode( RageDisplay::VideoModeParams p, bool &bNewDeviceOut );
 	void SwapBuffers();
 	void Update(float fDeltaTime);