make Quad less special. Create a "default" texture object for the

"no texture" properties.  This way, loaded sprites always have a
texture loaded.

stepmania/src/Quad.cpp

@@ -1,12 +1,15 @@
 #include "global.h"
 #include "Quad.h"
 #include "ActorUtil.h"
+#include "RageTextureManager.h"
 
 REGISTER_ACTOR_CLASS( Quad )
 
 
 void Quad::LoadFromNode( const XNode* pNode )
 {
+	Load( TEXTUREMAN->GetDefaultTextureID() );
+
 	// HACK: Bypass Sprite's texture loading.  Sprite should really derive from Quad.
 	Actor::LoadFromNode( pNode );
 }

stepmania/src/Quad.h

@@ -9,11 +9,6 @@
 class Quad : public Sprite
 {
 public:
-	Quad()
-	{
-		SetDrawIfTextureNull( true );
-	}	
-
 	void LoadFromNode( const XNode* pNode );
 	virtual Quad *Copy() const;
 };

stepmania/src/RageDisplay.h

@@ -194,6 +194,9 @@ public:
 		RageSurface* img, 		// must be in pixfmt
 		bool bGenerateMipMaps
 		) = 0;
+	/* Return a texture handle to the default texture, an opaque, all-white,
+	 * immutable texture.  Deleting or updating this texture has no effect. */
+	virtual unsigned CreateTextureDefault() = 0;
 	virtual void UpdateTexture( 
 		unsigned iTexHandle, 
 		RageSurface* img,

stepmania/src/RageDisplay_Null.h

@@ -24,6 +24,7 @@ public:
 		PixelFormat pixfmt, 
 		RageSurface* img,
 		bool bGenerateMipMaps ) { return 1; }
+	unsigned CreateTextureDefault() { return 0; }
 	void UpdateTexture( 
 		unsigned iTexHandle, 
 		RageSurface* img,

stepmania/src/RageDisplay_OGL.h

@@ -34,6 +34,7 @@ public:
 		PixelFormat pixfmt, 
 		RageSurface* img,
 		bool bGenerateMipMaps );
+	unsigned CreateTextureDefault() { return 0; }
 	void UpdateTexture( 
 		unsigned iTexHandle, 
 		RageSurface* img,

stepmania/src/RageTextureManager.cpp

@@ -89,6 +89,30 @@ void RageTextureManager::RegisterTexture( RageTextureID ID, RageTexture *pTextur
 	m_mapPathToTexture[ID] = pTexture;
 }
 
+static const RString g_sDefaultTextureName = "__blank__";
+RageTextureID RageTextureManager::GetDefaultTextureID()
+{
+	return RageTextureID( g_sDefaultTextureName );
+}
+
+class RageTexture_Default: public RageTexture
+{
+public:
+	RageTexture_Default():
+		RageTexture( RageTextureID() )
+	{
+		m_uTexHandle = DISPLAY->CreateTextureDefault();
+		m_iSourceWidth = m_iSourceHeight = 1;
+		m_iTextureWidth = m_iTextureHeight = 1;
+		m_iImageWidth = m_iImageHeight = 1;
+		CreateFrameRects();
+	}
+	unsigned GetTexHandle() const { return m_uTexHandle; }
+
+private:
+	unsigned m_uTexHandle;
+};
+
 // Load and unload textures from disk.
 RageTexture* RageTextureManager::LoadTextureInternal( RageTextureID ID )
 {
@@ -112,7 +136,9 @@ RageTexture* RageTextureManager::LoadTextureInternal( RageTextureID ID )
 	sExt.MakeLower();
 
 	RageTexture* pTexture;
-	if( sExt == "avi" || sExt == "mpg" || sExt == "mpeg" )
+	if( ID.filename == g_sDefaultTextureName )
+		pTexture = new RageTexture_Default;
+	else if( sExt == "avi" || sExt == "mpg" || sExt == "mpeg" )
 		pTexture = RageMovieTexture::Create( ID );
 	else
 		pTexture = new RageBitmapTexture( ID );

stepmania/src/RageTextureManager.h

@@ -84,6 +84,8 @@ public:
 	void EnableOddDimensionWarning() { m_iNoWarnAboutOddDimensions--; }
 	bool GetOddDimensionWarning() const { return m_iNoWarnAboutOddDimensions == 0; }
 
+	RageTextureID GetDefaultTextureID();
+
 private:
 	void DeleteTexture( RageTexture *t );
 	enum GCType { screen_changed, delayed_delete };

stepmania/src/Sprite.cpp

@@ -20,7 +20,6 @@ REGISTER_ACTOR_CLASS( Sprite )
 Sprite::Sprite()
 {
 	m_pTexture = NULL;
-	m_bDrawIfTextureNull = false;
 	m_iCurState = 0;
 	m_fSecsIntoState = 0.0f;
 	m_bUsingCustomTexCoords = false;
@@ -43,7 +42,6 @@ Sprite::Sprite( const Sprite &cpy ):
 	Actor( cpy )
 {
 #define CPY(a) a = cpy.a
-	CPY( m_bDrawIfTextureNull );
 	CPY( m_States );
 	CPY( m_iCurState );
 	CPY( m_fSecsIntoState );
@@ -557,7 +555,7 @@ void Sprite::DrawTexture( const TweenState *state )
 
 bool Sprite::EarlyAbortDraw() const
 {
-	return m_pTexture == NULL && !m_bDrawIfTextureNull;
+	return m_pTexture == NULL;
 }
 
 void Sprite::DrawPrimitives()

stepmania/src/Sprite.h

@@ -67,16 +67,14 @@ public:
 	virtual void PushSelf( lua_State *L );
 
 protected:
-	void SetDrawIfTextureNull( bool b ) { m_bDrawIfTextureNull = b; }
+	void LoadFromTexture( RageTextureID ID );
 
 private:
-	void LoadFromTexture( RageTextureID ID );
 	void LoadStatesFromTexture();
 
 	void DrawTexture( const TweenState *state );
 
 	RageTexture* m_pTexture;
-	bool	m_bDrawIfTextureNull;
 
 	struct State
 	{