add GetAnimationLengthSeconds

stepmania/src/Sprite.cpp

@@ -963,6 +963,8 @@ public:
 	static int scaletoclipped( T* p, lua_State *L )		{ p->ScaleToClipped( FArg(1),FArg(2) ); return 0; }
 	static int stretchtexcoords( T* p, lua_State *L )	{ p->StretchTexCoords( FArg(1),FArg(2) ); return 0; }
 	static int setstate( T* p, lua_State *L )			{ p->SetState( IArg(1) ); return 0; }
+	static int GetAnimationLengthSeconds( T* p, lua_State *L ) { lua_pushnumber( L, p->GetAnimationLengthSeconds() ); return 1; }
+
 	/* Texture commands; these could be moved to RageTexture* (even though that's
 	 * not an Actor) if these are needed for other things that use textures.
 	 * We'd need to break the command helpers into a separate function; RageTexture
@@ -980,6 +982,7 @@ public:
 		ADD_METHOD( scaletoclipped );
 		ADD_METHOD( stretchtexcoords );
 		ADD_METHOD( setstate );
+		ADD_METHOD( GetAnimationLengthSeconds );
 		ADD_METHOD( position );
 		ADD_METHOD( loop );
 		ADD_METHOD( rate );