first-pass: actor descriptions in Lua

stepmania/src/ActorUtil.cpp

@@ -314,6 +314,33 @@ static void MergeActorXML( XNode *pChild, const XNode *pParent )
 	}
 }
 
+namespace
+{
+	XNode *LoadXNodeFromLuaShowErrors( const RString &sFile )
+	{
+		RString sScript;
+		if( !GetFileContents(sFile, sScript) )
+			return NULL;
+
+		Lua *L = LUA->Get();
+
+		RString sError;
+		if( !LuaHelpers::RunScript(L, sScript, sFile, sError, 1) )
+		{
+			lua_pop( L, 1 );
+			LUA->Release( L );
+			sError = ssprintf( "Lua runtime error: %s", sError.c_str() );
+			Dialog::OK( sError, "LUA_ERROR" );
+			return NULL;
+		}
+
+		XNode *pRet = XmlFileUtil::XNodeFromTable( L );
+
+		LUA->Release( L );
+		return pRet;
+	}
+}
+
 /*
  * If pParent is non-NULL, it's the parent node when nesting XML, which is
  * used only by ActorUtil::LoadFromNode.
@@ -344,6 +371,16 @@ Actor* ActorUtil::MakeActor( const RString &sPath_, const XNode *pParent, Actor
 		}
 	}
 
+	if( ft == FT_Directory )
+	{
+		RString sLuaPath = sPath + "default.lua";
+		if( DoesFileExist(sLuaPath) )
+		{
+			sPath = sLuaPath;
+			ft = FT_Lua;
+		}
+	}
+
 	RString sDir = Dirname( sPath );
 	switch( ft )
 	{
@@ -367,6 +404,19 @@ Actor* ActorUtil::MakeActor( const RString &sPath_, const XNode *pParent, Actor
 			MergeActorXML( &xml, pParent );
 			return ActorUtil::LoadFromNode( sDir, &xml );
 		}
+	case FT_Lua:
+		{
+			auto_ptr<XNode> pNode( LoadXNodeFromLuaShowErrors(sPath) );
+			if( pNode.get() == NULL )
+			{
+				// XNode will warn about the error
+				return new Actor;
+			}
+
+			MergeActorXML( pNode.get(), pParent );
+			Actor *pRet = ActorUtil::LoadFromNode( sDir, pNode.get() );
+			return pRet;
+		}
 	case FT_Bitmap:
 	case FT_Movie:
 		{
@@ -503,6 +553,7 @@ static const char *FileTypeNames[] = {
 	"Movie", 
 	"Directory", 
 	"Xml", 
+	"Lua", 
 	"Model", 
 };
 XToString( FileType, NUM_FileType );
@@ -513,6 +564,7 @@ FileType ActorUtil::GetFileType( const RString &sPath )
 	sExt.MakeLower();
 	
 	if( sExt=="xml" )		return FT_Xml;
+	else if( sExt=="lua" )		return FT_Lua;
 	else if( 
 		sExt=="png" ||
 		sExt=="jpg" || 

stepmania/src/ActorUtil.h

@@ -33,6 +33,7 @@ enum FileType
 	FT_Movie, 
 	FT_Directory, 
 	FT_Xml, 
+	FT_Lua, 
 	FT_Model, 
 	NUM_FileType, 
 	FT_Invalid 

stepmania/src/XmlFileUtil.cpp

@@ -640,8 +640,113 @@ void XmlFileUtil::CompileXNodeTree( XNode *pNode, const RString &sFile )
 	LUA->Release( L );
 }
 
+namespace
+{
+	XNode *XNodeFromTableRecursive( lua_State *L, const RString &sName, LuaReference &ProcessedTables )
+	{
+		XNode *pNode = new XNode( sName );
+
+		/* Set the value of the node to the table. */
+		{
+			XNodeLuaValue *pValue = new XNodeLuaValue;
+			lua_pushvalue( L, -1 );
+			pValue->SetValueFromStack( L );
+			pNode->SetValueFrom( pValue );
+		}
+
+		/* Iterate over the table, pulling out attributes and tables to process. */
+		map<RString, LuaReference> NodesToAdd;
+		lua_pushnil( L );
+		while( lua_next(L, -2) )
+		{
+			lua_pushvalue( L, -2 );
+			RString sName;
+			LuaHelpers::Pop( L, sName );
+
+			/* If this entry is a table, add it recursively. */
+			if( lua_istable(L, -1) )
+			{
+				NodesToAdd[sName].SetFromStack( L );
+				continue;
+			}
+
+			if( lua_isstring(L, -1) && EndsWith(sName, "Command") )
+			{
+				RString sExpression;
+				LuaHelpers::Pop( L, sExpression );
+				LuaHelpers::ParseCommandList( L, sExpression, "" /* XXX */ );
+			}
+
+			/* Otherwise, add an attribute. */
+			XNodeLuaValue *pValue = new XNodeLuaValue;
+			pValue->SetValueFromStack( L );
+			pNode->AppendAttrFrom( sName, pValue );
+		}
+		lua_pop( L, 1 ); // pop nil
+
+		/* Recursively process tables. */
+		FOREACHM( RString, LuaReference, NodesToAdd, t )
+		{
+			const RString &sNodeName = t->first;
+			LuaReference &NodeToAdd = t->second;
+
+			/* Check if the table is on the stack. */
+			ProcessedTables.PushSelf( L );
+			NodeToAdd.PushSelf( L ); // push table
+			lua_gettable( L, -2 );
+
+			bool bSawThisTableAlready = !lua_isnil(L, -1);
+			lua_pop( L, 2 ); // pop lua_gettable result, ProcessedTables
+			if( bSawThisTableAlready )
+				continue;
+
+			/* Add the table to the stack. */
+			ProcessedTables.PushSelf( L );
+			NodeToAdd.PushSelf( L );
+			lua_pushboolean( L, true );
+			lua_settable( L, -3 );
+			lua_pop( L, 1 ); // pop ProcessedTables
+
+			NodeToAdd.PushSelf( L );
+			XNode *pNewNode = XNodeFromTableRecursive( L, sNodeName, ProcessedTables );
+			if( pNewNode )
+				pNode->AppendChild( pNewNode );
+
+			/* Remove the table from the stack. */
+			ProcessedTables.PushSelf( L );
+			NodeToAdd.PushSelf( L );
+			lua_pushnil( L );
+			lua_settable( L, -3 );
+			lua_pop( L, 1 ); // pop ProcessedTables
+		}
+
+		return pNode;
+	}
+
+}
+
 /*
- * (c) 2001-2004 Chris Danford
+ * Pop a table off of the stack, and return an XNode tree referring recursively
+ * to entries in the table.
+ *
+ * The table may not contain table cycles; if a cycle is detected, only the first
+ * table seen will have a corresponding XNode.
+ *
+ * Users of the resulting XNode may access the original table via PushValue.
+ */
+XNode *XmlFileUtil::XNodeFromTable( lua_State *L )
+{
+	/* Maintain a set of references that we've created.  Tables may loop; XNode trees may
+	 * not.  If we encounter a cycle, skip creating an XNode for that node. */
+	LuaReference ProcessedTables;
+	lua_newtable( L );
+	ProcessedTables.SetFromStack( L );
+
+	return XNodeFromTableRecursive( L, "Layer", ProcessedTables );
+}
+
+/*
+ * (c) 2001-2006 Chris Danford, Glenn Maynard
  * All rights reserved.
  * 
  * Permission is hereby granted, free of charge, to any person obtaining a

stepmania/src/XmlFileUtil.h

@@ -5,6 +5,7 @@
 
 class RageFileBasic;
 class XNode;
+struct lua_State;
 
 namespace XmlFileUtil
 {
@@ -19,6 +20,7 @@ namespace XmlFileUtil
 	bool SaveToFile( const XNode *pNode, RageFileBasic &f, const RString &sStylesheet = "", bool bWriteTabs = true );
 
 	void CompileXNodeTree( XNode *pNode, const RString &sFile );
+	XNode *XNodeFromTable( lua_State *L );
 }
 
 #endif