Do SetDefaultRenderStates in BeginFrame, instead of on init,

so we don't depend on state being preserved long-term, and
so every renderer doesn't have to do this.

stepmania/src/RageDisplay.cpp

@@ -121,11 +121,23 @@ RString RageDisplay::GetStats() const
 	return s;
 }
 
+bool RageDisplay::BeginFrame()
+{
+	this->SetDefaultRenderStates();
+
+	return true;
+}
+
 void RageDisplay::EndFrame()
 {
 	ProcessStatsOnFlip();
 }
 
+void RageDisplay::BeginConcurrentRendering()
+{
+	this->SetDefaultRenderStates();
+}
+
 void RageDisplay::StatsAddVerts( int iNumVertsRendered ) { g_iVertsRenderedSinceLastCheck += iNumVertsRendered; }
 
 /* Draw a line as a quad.  GL_LINES with SmoothLines off can draw line

stepmania/src/RageDisplay.h

@@ -152,7 +152,7 @@ public:
 	/* Call this when the resolution has been changed externally: */
 	virtual void ResolutionChanged();
 
-	virtual bool BeginFrame() = 0;	
+	virtual bool BeginFrame();
 	virtual void EndFrame();
 	virtual VideoModeParams GetActualVideoModeParams() const = 0;
 	bool IsWindowed() const { return this->GetActualVideoModeParams().windowed; }
@@ -167,7 +167,7 @@ public:
 	// thread before and after rendering.
 	virtual void BeginConcurrentRenderingMainThread() { }
 	virtual void EndConcurrentRenderingMainThread() { }
-	virtual void BeginConcurrentRendering() { }
+	virtual void BeginConcurrentRendering();
 	virtual void EndConcurrentRendering() { }
 
 	/* return 0 if failed or internal texture resource handle 

stepmania/src/RageDisplay_D3D.cpp

@@ -621,8 +621,6 @@ RString RageDisplay_D3D::TryVideoMode( const VideoModeParams &_p, bool &bNewDevi
 
 	ResolutionChanged();
 
-	this->SetDefaultRenderStates();
-	
 	return RString();	// mode change successful
 }
 
@@ -661,7 +659,6 @@ bool RageDisplay_D3D::BeginFrame()
 			if( sError != "" )
 				RageException::Throw( sError );
 
-			this->SetDefaultRenderStates();
 			break;
 		}
 	}
@@ -670,7 +667,8 @@ bool RageDisplay_D3D::BeginFrame()
 	g_pd3dDevice->Clear( 0, NULL, D3DCLEAR_TARGET|D3DCLEAR_ZBUFFER,
 						 D3DCOLOR_XRGB(0,0,0), 1.0f, 0x00000000 );
 	g_pd3dDevice->BeginScene();
-	return true;
+
+	return RageDisplay::BeginFrame();
 }
 
 static RageTimer g_LastFrameEndedAt( RageZeroTimer );

stepmania/src/RageDisplay_OGL.cpp

@@ -598,8 +598,6 @@ RString RageDisplay_OGL::TryVideoMode( const VideoModeParams &p, bool &bNewDevic
 		InitScalingScript();
 	}
 
-	this->SetDefaultRenderStates();
-
 	/* Set vsync the Windows way, if we can.  (What other extensions are there
 	 * to do this, for other archs?) */
 	if( GLExt.wglSwapIntervalEXT )
@@ -629,7 +627,8 @@ bool RageDisplay_OGL::BeginFrame()
 	glClearColor( 0,0,0,1 );
 	SetZWrite( true );
 	glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
-	return true;
+
+	return RageDisplay::BeginFrame();
 }
 
 void RageDisplay_OGL::EndFrame()
@@ -1584,7 +1583,7 @@ void RageDisplay_OGL::EndConcurrentRenderingMainThread()
 void RageDisplay_OGL::BeginConcurrentRendering()
 {
 	g_pWind->BeginConcurrentRendering();
-	SetDefaultRenderStates();
+	RageDisplay::BeginConcurrentRendering();
 }
 
 void RageDisplay_OGL::EndConcurrentRendering()