re-enabled alpha override and dithering for song BGs

stepmania/src/Background.cpp

@@ -133,6 +133,15 @@ void Background::LoadFromSong( Song* pSong )
 	//
 	BackgroundAnimation* pTempBGA;
 
+	
+	// Tricky!  The song background looks terrible unless its loaded with no alpha 
+	// and dithered.  Create a dummy sprite that loads the texture with the proper 
+	// hints so we don't have to hack up BackgroundAnimation to handle this special
+	// case.
+	Sprite sprDummy;
+	sprDummy.Load( sSongBackgroundPath, true, 4, 0, true, false );
+	
+
 	pTempBGA = new BackgroundAnimation;
 	pTempBGA->LoadFromStaticGraphic( sSongBackgroundPath );
 	m_BackgroundAnimations.Add( pTempBGA );

stepmania/src/RageBitmapTexture.cpp

@@ -128,19 +128,22 @@ void RageBitmapTexture::Create(
 	switch( dwTextureColorDepth )
 	{
 	case 16:
-//		switch( iAlphaBits )
-//		{
-//		case 0:		fmtTexture = D3DFMT_R5G6B5;		break;
-//		case 1:		fmtTexture = D3DFMT_A1R5G5B5;	break;
-//		default:	fmtTexture = D3DFMT_A4R4G4B4;	break;
-//		}
-
-		// Ignore dwTextureColorDepth, and infer based on image format
-		switch( ddii.Format )
+		switch( iAlphaBits )
 		{
-		case D3DFMT_P8:		fmtTexture = D3DFMT_A1R5G5B5;	break;
-		default:			fmtTexture = D3DFMT_A4R4G4B4;	break;
+		case 0:		fmtTexture = D3DFMT_R5G6B5;		break;
+		case 1:		fmtTexture = D3DFMT_A1R5G5B5;	break;
+		case 4:
+			// Ignore dwTextureColorDepth, and infer based on image format
+			switch( ddii.Format )
+			{
+			case D3DFMT_P8:		fmtTexture = D3DFMT_A1R5G5B5;	break;
+			default:			fmtTexture = D3DFMT_A4R4G4B4;	break;
+			}
+			break;
+		default:
+			ASSERT(0);	// invalid iAlphaBits value
 		}
+
 		break;
 	case 32:
 		fmtTexture = D3DFMT_A8R8G8B8;

stepmania/src/Song.cpp

@@ -45,7 +45,7 @@
 #include "NotesLoaderKSF.h"
 #include "NotesWriterDWI.h"
 
-const int FILE_CACHE_VERSION = 68;	// increment this when Song or Notes changes to invalidate cache
+const int FILE_CACHE_VERSION = 69;	// increment this when Song or Notes changes to invalidate cache
 
 
 int CompareBPMSegments(const void *arg1, const void *arg2)