From: Charles McGarvey <chazmcgarvey@brokenzipper.com>
Date: Sun, 14 Mar 2010 18:31:35 +0000 (-0600)
Subject: script API improvements
X-Git-Url: https://git.dogcows.com/gitweb?p=chaz%2Fyoink;a=commitdiff_plain;h=4107dd30ca1a4c7d1a5cd6c0999b9afb5adff779

script API improvements
---

diff --git a/cscope.make b/cscope.make
index 47c2811..3349d6d 100755
--- a/cscope.make
+++ b/cscope.make
@@ -1,12 +1,12 @@
 #!/bin/sh
 
-current=`pwd`
+current="$PWD"
 cd /
 find "$current" \
 -iname "*.c"	-o \
 -iname "*.h"	-o \
 -iname "*.cc"	-o \
--iname "*.hh"	|sed '/ / s/^\(.*\)/"\1"/' >"$current/cscope.files"
+-iname "*.hh"	| sed '/ / s/^\(.*\)/"\1"/' >"$current/cscope.files"
 
 cd "$current"
 
diff --git a/data/scenes/Classic.lua b/data/scenes/Classic.lua
index 75ea02a..2d00a67 100644
--- a/data/scenes/Classic.lua
+++ b/data/scenes/Classic.lua
@@ -5,11 +5,6 @@ LogInfo("-----",
 		"Converted to Lua by Charles McGarvey",
 		"-----")
 
---for key,value in pairs(_G) do print(key, value) end
-meh = Blah:new()
-meh:sayHello()
-print(meh:myStr(3.1415))
-
 -- Scene API:
 --
 -- Functions:
@@ -26,8 +21,7 @@ print(meh:myStr(3.1415))
 -- detail - level of detail of the scene (HIGH, MEDIUM, or LOW)
 
 
-SetBounds({-5, 0, -6}, {45, 15, 7})
-
+SetBounds({-5, 0, -6}, {45, 15, 4})
 
 -- Left end tower block
 -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
diff --git a/src/Animation.cc b/src/Animation.cc
index 6df8556..bd31f9b 100644
--- a/src/Animation.cc
+++ b/src/Animation.cc
@@ -63,17 +63,12 @@ public:
 			 * animation file.
 			 */
 		
-			Frame(Mf::Script& script, Mf::Script::Slot table) :
+			Frame(const Mf::Script::Slot& table) :
 				mIndex(0),
 				mDuration(1.0)
 			{
-				table.pushField("index");
-				script[-1].get(mIndex);
-				script.pop();
-
-				table.pushField("duration");
-				script[-1].get(mDuration);
-				script.pop();
+				table.get(mIndex,    "index");
+				table.get(mDuration, "duration");
 			}
 		};
 
@@ -99,46 +94,36 @@ public:
 			 * the frame's constructor which loads each individual frame.
 			 */
 
-			Sequence(Mf::Script& script, Mf::Script::Slot table) :
+			Sequence(const Mf::Script::Slot& table) :
 				mDelay(0.0),
 				mLoop(true)
 			{
-				table.pushField("delay");
-				script[-1].get(mDelay);
-				script.pop();
-
-				table.pushField("loop");
-				script[-1].get(mLoop);
-				script.pop();
-
-				table.pushField("next");
-				script[-1].get(mNext);
-				script.pop();
+				table.get(mDelay, "delay");
+				table.get(mLoop,  "loop");
+				table.get(mNext,  "next");
 
 				// TODO - sequence class/type not yet implemented
 
-				table.pushField("frames");
-				Mf::Script::Slot frameTable = script.getTop();
+				Mf::Script::Slot frameTable = table.pushField("frames");
 				if (frameTable.isTable())
 				{
-					Mf::Script::Slot top = script[-1];
-					int index = 1;
-
-					for (;;)
+					int max = frameTable.length();
+					for (int index = 1; index <= max; ++index)
 					{
-						script.push(index);
-						frameTable.pushField();
+						Mf::Script::Slot top = frameTable.pushField(index);
 
 						if (top.isTable())
 						{
-							mFrames.push_back(Frame(script, top));
+							mFrames.push_back(Frame(top));
+						}
+						else
+						{
+							Mf::logWarning << "invalid frame at index "
+										   << index << std::endl;
 						}
-						else break;
-
-						++index;
 					}
 				}
-				script.pop();
+				frameTable.remove();
 			}
 		};
 
@@ -179,8 +164,7 @@ public:
 			std::string nameStr;
 			name.get(nameStr);
 
-			mSequences.insert(std::make_pair(nameStr,
-											 Sequence(script, table)));
+			mSequences.insert(std::make_pair(nameStr, Sequence(table)));
 
 			return 0;
 		}
@@ -192,13 +176,13 @@ public:
 								  boost::bind(&Data::defineSequence,
 											  this, _1));
 
-			script.push(1); script.set("ATTACK");
-			script.push(2); script.set("CHARGE");
-			script.push(3); script.set("FLY");
-			script.push(4); script.set("HIT");
-			script.push(5); script.set("JUMP");
-			script.push(6); script.set("RUN");
-			script.push(7); script.set("STAND");
+			script.globals().setField("ATTACK",	1);
+			script.globals().setField("CHARGE",	2);
+			script.globals().setField("FLY",	3);
+			script.globals().setField("HIT",	4);
+			script.globals().setField("JUMP",	5);
+			script.globals().setField("RUN",	6);
+			script.globals().setField("STAND",	7);
 		}
 
 
diff --git a/src/GameLayer.cc b/src/GameLayer.cc
index 8f2f4ec..d68522e 100644
--- a/src/GameLayer.cc
+++ b/src/GameLayer.cc
@@ -43,8 +43,8 @@ void GameLayer::loadSceneLoader()
 		throw Mf::Error(Mf::Error::SCRIPT_ERROR, str);
 	}
 
-	mState.script.getGlobalTable().pushField("scenes");
-	mState.script.getTop().get(mState.sceneList);
+	mState.script.globals().pushField("scenes");
+	mState.script.top().get(mState.sceneList);
 	if (mState.sceneList.size() == 0)
 	{
 		throw Mf::Error(Mf::Error::SCRIPT_ERROR,
@@ -69,17 +69,14 @@ void GameLayer::advanceScene(Mf::Settings& settings)
 			throw Mf::Error(Mf::Error::SCRIPT_ERROR, str);
 		}
 
-		mState.script.getGlobalTable().pushField("Event");
-		if (mState.script[-1].isTable())
+		Mf::Script::Slot table = mState.script.globals().pushField("Event");
+		if (table.isTable())
 		{
-			mState.script[-1].pushField("Think");
-			mState.script.set("Think", Mf::Script::REGISTRY);
-			mState.script.pop(2);
-		}
-		else
-		{
-			mState.script.pop();
+			mState.script.push("Think");
+			table.pushField("Think");
+			mState.script.registry().setField();
 		}
+		mState.script.pop();
 	}
 }
 
@@ -149,7 +146,7 @@ void GameLayer::update(Mf::Scalar t, Mf::Scalar dt)
 
 void GameLayer::thinkTimer()
 {
-	mState.script.getRegistryTable().pushField("Think");
+	mState.script.registry().pushField("Think");
 	if (mState.script[-1].isFunction()) mState.script.call();
 	else                                mState.script.pop();
 }
diff --git a/src/Makefile.am b/src/Makefile.am
index 9a7f514..b63b7d2 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -12,6 +12,7 @@
 noinst_LIBRARIES = libmoof.a
 
 libmoof_a_SOURCES = \
+					Moof/Aabb.cc \
 					Moof/Aabb.hh \
 					Moof/Backend.cc \
 					Moof/Backend.hh \
diff --git a/src/Moof/Aabb.cc b/src/Moof/Aabb.cc
new file mode 100644
index 0000000..125e9d1
--- /dev/null
+++ b/src/Moof/Aabb.cc
@@ -0,0 +1,25 @@
+
+/*]  Copyright (c) 2009-2010, Charles McGarvey  [**************************
+**]  All rights reserved.
+*
+* vi:ts=4 sw=4 tw=75
+*
+* Distributable under the terms and conditions of the 2-clause BSD license;
+* see the file COPYING for a complete text of the license.
+*
+**************************************************************************/
+
+#include "Aabb.hh"
+#include "Script.hh"
+
+
+namespace Mf {
+
+
+void Aabb::importClass(Script& script)
+{
+}
+
+
+} // namespace Mf
+
diff --git a/src/Moof/Aabb.hh b/src/Moof/Aabb.hh
index 8fcdbc3..e510ce3 100644
--- a/src/Moof/Aabb.hh
+++ b/src/Moof/Aabb.hh
@@ -26,6 +26,9 @@
 namespace Mf {
 
 
+class Script;
+
+
 /**
  * Axis-aligned Bounding Box
  */
@@ -212,6 +215,9 @@ struct Aabb : public Cullable, public Drawable, public Shape<D>
 	{
 		return true;
 	}
+
+
+	static void importClass(Script& script);
 };
 
 
diff --git a/src/Moof/Interpolator.hh b/src/Moof/Interpolator.hh
index d918a8d..db91e10 100644
--- a/src/Moof/Interpolator.hh
+++ b/src/Moof/Interpolator.hh
@@ -117,7 +117,7 @@ private:
 };
 
 
-template <typename T = Scalar>
+template <class T = Scalar>
 class Linear
 {
 public:
diff --git a/src/Moof/Log.hh b/src/Moof/Log.hh
index c773630..324fdee 100644
--- a/src/Moof/Log.hh
+++ b/src/Moof/Log.hh
@@ -64,7 +64,7 @@ public:
 		mType(type) /* only pass literal strings */ {}
 
 
-	template <typename T>
+	template <class T>
 	void operator () (const T& item)
 	{
 		*this << item << std::endl;
@@ -72,7 +72,7 @@ public:
 
 private:
 
-	template <typename T> friend std::ostream& operator << (Log&, const T&);
+	template <class T> friend std::ostream& operator << (Log&, const T&);
 
 	static Level	gLevel;
 
@@ -89,7 +89,7 @@ extern Log logWarning;
 extern Log logInfo;
 
 
-template <typename T>
+template <class T>
 inline std::ostream& operator << (Log& logObj, const T& item)
 {
 	if (Log::gLevel < logObj.mLevel) return nullLog;
diff --git a/src/Moof/Math.hh b/src/Moof/Math.hh
index 4293207..d557c7f 100644
--- a/src/Moof/Math.hh
+++ b/src/Moof/Math.hh
@@ -85,7 +85,7 @@ inline Vector3 promote(const Vector2& vec, Scalar extra = 0.0)
 }
 
 
-template <typename R, typename P>
+template <class R, class P>
 inline R convert(const P& p)
 {
 	return R(p);
@@ -115,11 +115,11 @@ inline Vector3 convert<Vector3,Vector2>(const Vector2& vec)
 	return Vector3(vec[0], vec[1], SCALAR(0.0));
 }
 
-template <typename P>
+template <class P>
 struct cast
 {
 	cast(const P& p) : param(p) {}
-	template <typename R>
+	template <class R>
 	operator R() { return convert<R,P>(param); }
 private:
 	const P& param;
@@ -153,7 +153,7 @@ inline bool isEqual(Scalar a, Scalar b, Scalar epsilon = EPSILON)
 // Derivative_Type operator+(const Derivative_Type& other) const
 // Derivative_Type operator*(const Derivative_Type& other) const
 
-template<typename S, typename D>
+template <class S, class D>
 inline D evaluate(const S& state, Scalar t)
 {
 	D derivative;
@@ -161,7 +161,7 @@ inline D evaluate(const S& state, Scalar t)
 	return derivative;
 }
 
-template<typename S, typename D>
+template <class S, class D>
 inline D evaluate(S state,  Scalar t, Scalar dt, const D& derivative)
 {
 	state.step(derivative, dt);
@@ -169,7 +169,7 @@ inline D evaluate(S state,  Scalar t, Scalar dt, const D& derivative)
 }
 
 
-template<typename S, typename D>
+template <class S, class D>
 inline void euler(S& state, Scalar t, Scalar dt)
 {
 	D a = evaluate<S,D>(state, t);
@@ -177,7 +177,7 @@ inline void euler(S& state, Scalar t, Scalar dt)
 	state.step(a, dt);
 }
 
-template<typename S, typename D>
+template <class S, class D>
 inline void rk2(S& state, Scalar t, Scalar dt)
 {
 	D a = evaluate<S,D>(state, t);
@@ -186,7 +186,7 @@ inline void rk2(S& state, Scalar t, Scalar dt)
 	state.step(b, dt);
 }
 
-template<typename S, typename D>
+template <class S, class D>
 inline void rk4(S& state, Scalar t, Scalar dt)
 {
 	D a = evaluate<S,D>(state, t);
diff --git a/src/Moof/Script.hh b/src/Moof/Script.hh
index 620db5b..0828411 100644
--- a/src/Moof/Script.hh
+++ b/src/Moof/Script.hh
@@ -99,17 +99,9 @@ public:
 		int index;
 
 
-		/**
-		 * A default-constructed Slot is invalid until a valid Slot is
-		 * assigned to it.  The only method that should be called on such a
-		 * Slot is isValid(), otherwise chaos may ensue.  In this case, the
-		 * Slot will be invalid even if index is manually changed to a
-		 * valid index.  You have to index the script itself to get a valid
-		 * Slot.
-		 */
-		Slot(lua_State* s = 0, int i = 0) :
+		Slot(const Script& s, int i = 0) :
 			index(i),
-			mState(s) {}
+			mScript(const_cast<Script&>(s)) {}
 
 		/**
 		 * A copied value presently points to the same value, except the
@@ -118,36 +110,36 @@ public:
 		 * normalized index copied into the new value object.
 		 */
 
-		Slot(const Slot& copy) :
-			index(copy.getRealIndex()),
-			mState(copy.mState) {}
+		//Slot(const Slot& copy) :
+			//index(copy.positiveIndex()),
+			//mScript(copy.mScript) {}
 
 
 		// check the type of the value
 		bool isBoolean() const
-		{ return (bool)lua_isboolean(mState, index); }
+		{ return (bool)lua_isboolean(mScript.mState, index); }
+		bool isImportedFunction() const
+		{ return (bool)lua_iscfunction(mScript.mState, index); }
 		bool isFunction() const
-		{ return (bool)lua_isfunction(mState, index); }
+		{ return (bool)lua_isfunction(mScript.mState, index); }
 		bool isNil() const
-		{ return (bool)lua_isnil(mState, index); }
+		{ return (bool)lua_isnil(mScript.mState, index); }
 		bool isNone() const
-		{ return (bool)lua_isnone(mState, index); }
-		bool isValid() const
-		{ return mState != 0 && !isNone(); }
+		{ return (bool)lua_isnone(mScript.mState, index); }
 		bool isNoneOrNil() const
-		{ return (bool)lua_isnoneornil(mState, index); }
+		{ return (bool)lua_isnoneornil(mScript.mState, index); }
 		bool isNumber() const
-		{ return (bool)lua_isnumber(mState, index); }
+		{ return (bool)lua_isnumber(mScript.mState, index); }
 		bool isString() const
-		{ return (bool)lua_isstring(mState, index); }
+		{ return (bool)lua_isstring(mScript.mState, index); }
 		bool isTable() const
-		{ return (bool)lua_istable(mState, index); }
+		{ return (bool)lua_istable(mScript.mState, index); }
 		bool isThread() const
-		{ return (bool)lua_isthread(mState, index); }
+		{ return (bool)lua_isthread(mScript.mState, index); }
 		bool isData() const
-		{ return (bool)lua_isuserdata(mState, index); }
+		{ return (bool)lua_isuserdata(mScript.mState, index); }
 		bool isLightData() const
-		{ return (bool)lua_islightuserdata(mState, index); }
+		{ return (bool)lua_islightuserdata(mScript.mState, index); }
 
 		/**
 		 * Check the value and throw an error if its the wrong type.
@@ -163,58 +155,83 @@ public:
 		 * before any C++ objects are even constructed.
 		 */
 
-		void requireType(Type type) const
+		void requireType(Type t) const
 		{
-			if (type != getType())
+			if (t != type())
 			{
-				luaL_typerror(mState, index, lua_typename(mState, type));
+				luaL_typerror(mScript.mState, index,
+							  lua_typename(mScript.mState, t));
 			}
 		}
 
-		void throwError(const char* error)
+		void raise(const char* error)
 		{
-			luaL_argerror(mState, index, error);
+			luaL_argerror(mScript.mState, index, error);
 		}
 
 
 		Slot& requireBoolean()
 		{
-			if (!isBoolean()) luaL_typerror(mState, index, "boolean");
+			if (!isBoolean())
+			{
+				luaL_typerror(mScript.mState, index, "boolean");
+			}
 			return *this;
 		}
 		Slot& requireNumber()
 		{
-			if (!isNumber()) luaL_typerror(mState, index, "number");
+			if (!isNumber())
+			{
+				luaL_typerror(mScript.mState, index, "number");
+			}
 			return *this;
 		}
 		Slot& requireString()
 		{
-			if (!isString()) luaL_typerror(mState, index, "string");
+			if (!isString())
+			{
+				luaL_typerror(mScript.mState, index, "string");
+			}
 			return *this;
 		}
 		Slot& requireTable()
 		{
-			if (!isTable()) luaL_typerror(mState, index, "table");
+			if (!isTable())
+			{
+				luaL_typerror(mScript.mState, index, "table");
+			}
 			return *this;
 		}
 		Slot& requireFunction()
 		{
-			if (!isFunction()) luaL_typerror(mState, index, "function");
+			if (!isFunction())
+			{
+				luaL_typerror(mScript.mState, index, "function");
+			}
 			return *this;
 		}
 		Slot& requireData()
 		{
-			if (!isData()) luaL_typerror(mState, index, "data");
+			if (!isData())
+			{
+				luaL_typerror(mScript.mState, index, "data");
+			}
 			return *this;
 		}
 		Slot& requireNil()
 		{
-			if (!isNil()) luaL_typerror(mState, index, "nil");
+			if (!isNil())
+			{
+				luaL_typerror(mScript.mState, index, "nil");
+			}
 			return *this;
 		}
 		Slot& requireThread()
 		{
-			if (!isThread()) luaL_typerror(mState, index, "thread");
+			if (!isThread())
+			{
+				luaL_typerror(mScript.mState, index, "thread");
+			}
 			return *this;
 		}
 
@@ -223,18 +240,18 @@ public:
 		 * Get the type of the value.
 		 */
 
-		Type getType() const
+		Type type() const
 		{
-			return (Type)lua_type(mState, index);
+			return (Type)lua_type(mScript.mState, index);
 		}
 
 		/**
 		 * Get the name of the type of the value as a string.
 		 */
 
-		std::string getTypeName() const
+		std::string typeName() const
 		{
-			return std::string(luaL_typename(mState, index));
+			return std::string(luaL_typename(mScript.mState, index));
 		}
 
 
@@ -243,14 +260,14 @@ public:
 		 * Lua.
 		 */
 
-		size_t getLength() const
+		size_t length() const
 		{
-			return lua_objlen(mState, index);
+			return lua_objlen(mScript.mState, index);
 		}
 
-		int getRealIndex() const
+		int positiveIndex() const
 		{
-			if (index < 0) return lua_gettop(mState) + 1 + index;
+			if (index < 0) return index + lua_gettop(mScript.mState) + 1;
 			else           return index;
 		}
 
@@ -260,23 +277,34 @@ public:
 		 * functions).
 		 */
 
-		const void* getIdentifier() const
+		const void* id() const
+		{
+			return lua_topointer(mScript.mState, index);
+		}
+
+		bool isIdentical(const Slot& rhs) const
+		{
+			return &mScript == &(rhs.mScript) && index == rhs.index;
+		}
+
+		operator bool () const
 		{
-			return lua_topointer(mState, index);
+			return !isNone();
 		}
 
 
 		bool operator == (const Slot& rhs) const
 		{
-			return (bool)lua_equal(mState, index, rhs.index);
+			return (bool)lua_equal(mScript.mState, index, rhs.index);
 		}
 		bool operator != (const Slot& rhs) const
 		{
 			return !(*this == rhs);
 		}
+
 		bool operator < (const Slot& rhs) const
 		{
-			return (bool)lua_lessthan(mState, index, rhs.index);
+			return (bool)lua_lessthan(mScript.mState, index, rhs.index);
 		}
 		bool operator <= (const Slot& rhs) const
 		{
@@ -290,29 +318,18 @@ public:
 		{
 			return !(*this < rhs);
 		}
-		operator bool () const
-		{
-			return (bool)lua_toboolean(mState, index);
-		}
-
-		Slot& operator = (const Slot& rhs)
-		{
-			rhs.pushCopy();
-			replaceWithTop();
-			return *this;
-		}
 
 
 		/**
 		 * Convert the underlying value to a C++ type.
 		 */
 
-		template <typename T>
+		template <class T>
 		bool get(T& value) const
 		{
 			if (isNumber())
 			{
-				value = (T)lua_tointeger(mState, index);
+				value = (T)lua_tointeger(mScript.mState, index);
 				return true;
 			}
 			return false;
@@ -322,7 +339,7 @@ public:
 		{
 			if (isNumber())
 			{
-				value = (float)lua_tonumber(mState, index);
+				value = (float)lua_tonumber(mScript.mState, index);
 				return true;
 			}
 			return false;
@@ -331,7 +348,7 @@ public:
 		{
 			if (isNumber())
 			{
-				value = (double)lua_tonumber(mState, index);
+				value = (double)lua_tonumber(mScript.mState, index);
 				return true;
 			}
 			return false;
@@ -341,62 +358,82 @@ public:
 		{
 			if (isBoolean())
 			{
-				value = (bool)lua_toboolean(mState, index);
+				value = (bool)lua_toboolean(mScript.mState, index);
 				return true;
 			}
 			return false;
 		}
 
-		bool get(std::string& value) const
+		bool get(const char*& value, size_t& size) const
 		{
 			if (isString())
 			{
-				size_t size;
-				const char* str = lua_tolstring(mState, index, &size);
+				value = lua_tolstring(mScript.mState, index, &size);
+				return true;
+			}
+			return false;
+		}
+
+		bool get(std::string& value) const
+		{
+			const char*	str;
+			size_t		size;
+			if (get(str, size))
+			{
 				value.assign(str, size);
 				return true;
 			}
 			return false;
 		}
 
-		template <typename T>
+		bool get(void*& value) const
+		{
+			if (isData())
+			{
+				value = lua_touserdata(mScript.mState, index);
+				return true;
+			}
+			return false;
+		}
+
+		template <class T>
 		bool get(std::vector<T>& array) const
 		{
 			if (!isTable()) return false;
 
 			array.clear();
 
-			Slot	value(mState, -1);
-			int		realIndex = getRealIndex();
+			Slot	value = mScript[-1];
+			int		realIndex = positiveIndex();
 
 			bool done = false;
 			for (int i = 1; !done; ++i)
 			{
-				lua_rawgeti(mState, realIndex, i);
+				lua_rawgeti(mScript.mState, realIndex, i);
 
 				T v;
 				if (value.get(v)) array.push_back(v);
 				else              done = true;
 
-				lua_pop(mState, 1);
+				mScript.pop();
 			}
 
 			return true;
 		}
 
-		template <typename T>
+		template <class T>
 		bool get(std::map<std::string,T>& dictionary) const
 		{
 			if (!isTable()) return false;
 
 			dictionary.clear();
 
-			Slot	key(mState, -2);
-			Slot	value(mState, -1);
-			int		realIndex = getRealIndex();
+			Slot	key = mScript[-2];
+			Slot	value = mScript[-1];
+			int		realIndex = positiveIndex();
 
-			lua_pushnil(mState);
-			while (lua_next(mState, realIndex) != 0)
+			mScript.pushNil();
+			while (lua_next(mScript.mState, realIndex) != 0)
 			{
 				std::string k;
 				if (!key.isNumber() && key.get(k))
@@ -404,9 +441,9 @@ public:
 					T v;
 					if (value.get(v)) dictionary[k] = v;
 				}
-				lua_pop(mState, 1);
+				mScript.pop();
 			}
-			lua_pop(mState, 1);
+			mScript.pop();
 
 			return true;
 		}
@@ -415,37 +452,79 @@ public:
 		 * Get the value of a field from the table.
 		 */
 
-		template <typename T, typename V>
+		template <class T, class V>
 		bool get(T& value, V field) const
 		{
-			pushField(field);
-			bool ret = Slot(mState, -1).get(value);
-			lua_pop(mState, 1);
+			bool ret = pushField(field).get(value);
+			mScript.pop();
 			return ret;
 		}
 
 
+		template <class T, class V>
+		void setField(T field, V value)
+		{
+			logWarning << "setting " << field << ", " << value << std::endl;
+			mScript.push(field);
+			mScript.push(value);
+			setField();
+		}
+
+		void setField()
+		{
+			lua_settable(mScript.mState, index);
+		}
+
+
+		template <class T>
+		void setField(const std::string& field, T value)
+		{
+			setField(field.c_str(), value);
+		}
+		template <class T>
+		void setField(const char* field, T value)
+		{
+			logWarning << "setfield " << field << ", " << value << std::endl;
+			mScript.push(value);
+			lua_setfield(mScript.mState, index, field);
+		}
+
+
 		/**
-		 * Copy the value and push the copy to the stack.
+		 * This set method, as opposed to the others, sets the value of the
+		 * actual slot.  The others set table values.
 		 */
+		template <class T>
+		void set(T value)
+		{
+			mScript.push(value);
+			replace();
+		}
 
-		void pushCopy() const
+		void set()
 		{
-			lua_pushvalue(mState, index);
+			replace();
 		}
 
+
 		/**
 		 * Replace this value with the value at the top of the stack.
 		 */
 
-		void replaceWithTop()
+		void replace()
 		{
-			lua_replace(mState, index);
+			lua_replace(mScript.mState, index);
 		}
 
 		void remove()
 		{
-			lua_remove(mState, index);
+			lua_remove(mScript.mState, index);
+		}
+
+		void pop()
+		{
+			// removes this slot, taking with it everything above it
+			mScript.pop(mScript.stackSize() - index + 1);
 		}
 
 		/**
@@ -455,35 +534,70 @@ public:
 
 		void insertTopHere()
 		{
-			lua_insert(mState, index);
+			lua_insert(mScript.mState, index);
 		}
 
+
+		/**
+		 * Copy the value and push the copy to the stack.
+		 */
+
+		Slot pushCopy() const
+		{
+			lua_pushvalue(mScript.mState, index);
+			return mScript.top();
+		}
 		
-		void pushMetaTable() const
+		Slot pushMetaTable() const
+		{
+			lua_getmetatable(mScript.mState, index);
+			return mScript.top();
+		}
+
+		Slot pushEnvironment() const
+		{
+			lua_getfenv(mScript.mState, index);
+			return mScript.top();
+		}
+
+
+		Slot pushField() const
 		{
-			lua_getmetatable(mState, index);
+			lua_gettable(mScript.mState, index);
+			return mScript.top();
 		}
 
-		void pushField() const
+		template <class T>
+		Slot pushField(T index) const
 		{
-			lua_gettable(mState, index);
+			mScript.push(index);
+			return pushField();
 		}
 
-		void pushField(const std::string& name) const
+		Slot pushField(const std::string& name) const
+		{
+			return pushField(name.c_str());
+		}
+		Slot pushField(const char* name) const
 		{
-			lua_getfield(mState, index, name.c_str());
+			lua_getfield(mScript.mState, index, name);
+			return mScript.top();
 		}
 
-		void pushField(size_t index) const
+
+		Script& script()
 		{
-			lua_pushinteger(mState, lua_Integer(index));
-			pushField();
+			return mScript;
 		}
 
+		const Script& script() const
+		{
+			return mScript;
+		}
 
 	private:
 
-		lua_State* mState;
+		Script& mScript;
 	};
 
 
@@ -508,8 +622,7 @@ public:
 	{
 		if (mState) destroy();
 		mState = luaL_newstate();
-		lua_pushlightuserdata(mState, this);
-		lua_setfield(mState, LUA_REGISTRYINDEX, "Script_hh_Object");
+		registry().setField("Script_hh_Object", (void*)this);
 	}
 
 
@@ -638,7 +751,7 @@ public:
 	 * after cleaning up such objects.
 	 */
 
-	void throwError()
+	void raise()
 	{
 		lua_error(mState);
 	}
@@ -648,24 +761,24 @@ public:
 	 * Get significant values.
 	 */
 
-	Slot getGlobalTable() const
+	Slot globals() const
 	{
-		return Slot(mState, GLOBALS);
+		return Slot(*this, GLOBALS);
 	}
 
-	Slot getRegistryTable() const
+	Slot registry() const
 	{
-		return Slot(mState, REGISTRY);
+		return Slot(*this, REGISTRY);
 	}
 
-	Slot getEnvironmentTable() const
+	Slot environment() const
 	{
-		return Slot(mState, ENVIRONMENT);
+		return Slot(*this, ENVIRONMENT);
 	}
 
-	Slot getTop() const
+	Slot top() const
 	{
-		return Slot(mState, lua_gettop(mState));
+		return Slot(*this, stackSize());
 	}
 
 	/**
@@ -673,19 +786,19 @@ public:
 	 * value.
 	 */
 
-	int getSize() const
+	int stackSize() const
 	{
 		return lua_gettop(mState);
 	}
 
-	void setSize(int size)
+	void setStackSize(int size)
 	{
 		lua_settop(mState, size);
 	}
 
-	void clear()
+	void clearStack()
 	{
-		setSize(0);
+		setStackSize(0);
 	}
 
 
@@ -707,7 +820,7 @@ public:
 	 * Concatenates the top-most n slots on the stack.
 	 */
 
-	void concat(int n = 2)
+	void concatenate(int n = 2)
 	{
 		lua_concat(mState, n);
 	}
@@ -717,81 +830,96 @@ public:
 	 * Push some values onto the stack.
 	 */
 
-	template <typename T>
-	void push(T value)
+	template <class T>
+	Slot push(T value)
 	{
 		lua_pushinteger(mState, lua_Integer(value));
+		return top();
 	}
 
-	void push(bool value)
+	Slot push(bool value)
 	{
 		lua_pushboolean(mState, int(value));
+		return top();
 	}
 
-	void push(float value)
+	Slot push(float value)
 	{
 		lua_pushnumber(mState, (lua_Number)value);
+		return top();
 	}
-	void push(double value)
+	Slot push(double value)
 	{
 		lua_pushnumber(mState, (lua_Number)value);
+		return top();
 	}
 
-	void push(const std::string& value)
+	Slot push(const std::string& value)
 	{
 		lua_pushlstring(mState, value.c_str(), value.length());
+		return top();
 	}
-	void push(const char* value)
+	Slot push(const char* value)
 	{
 		lua_pushstring(mState, value);
+		return top();
 	}
-	void push(const char* value, size_t length)
+	Slot push(const char* value, size_t length)
 	{
 		lua_pushlstring(mState, value, length);
+		return top();
 	}
 
-	void push(const Function& function)
+	Slot push(const Function& function)
 	{
 		mFunctions.push_back(function);
-
 		lua_pushlightuserdata(mState, (void*)&mFunctions.back());
 		lua_pushcclosure(mState, dispatchCall, 1);
+		return top();
 	}
 
-	void push(void* data)
+	Slot push(void* data)
 	{
 		lua_pushlightuserdata(mState, data);
+		return top();
 	}
 
-	void pushNil()
+	Slot pushNil()
 	{
 		lua_pushnil(mState);
+		return top();
 	}
 
-	void pushFromThread(Script& thread, int n)
+	Slot pushFromThread(Script& thread, int n)
 	{
 		lua_xmove(thread.mState, mState, n);
+		return top();
 	}
 
-	Result pushCode(const std::string& filename)
+	Slot pushCode(const std::string& file, Result& result)
 	{
-		return (Result)luaL_loadfile(mState, filename.c_str());
+		result = (Result)luaL_loadfile(mState, file.c_str());
+		return top();
 	}
 
-	Result pushCode(const std::string& name, const char* buffer,
-					size_t size)
+	Slot pushCode(const std::string& name, const char* buffer,
+				  size_t size, Result& result)
 	{
-		return (Result)luaL_loadbuffer(mState, buffer, size, name.c_str());
+		result = (Result)luaL_loadbuffer(mState,
+										 buffer, size, name.c_str());
+		return top();
 	}
 
-	void* pushNewData(size_t size)
+	Slot pushNewData(void*& data, size_t size)
 	{
-		return lua_newuserdata(mState, size);
+		data = lua_newuserdata(mState, size);
+		return top();
 	}
 
-	void pushNewTable()
+	Slot pushNewTable(int narr = 0, int nrec = 0)
 	{
-		lua_newtable(mState);
+		lua_createtable(mState, narr, nrec);
+		return top();
 	}
 
 
@@ -824,22 +952,7 @@ public:
 
 	Slot operator [] (int index) const
 	{
-		return Slot(mState, index);
-	}
-
-
-	/**
-	 * Getting and setting fields of a table.
-	 */
-
-	void pushField(const std::string& field, int index = GLOBALS) const
-	{
-		lua_getfield(mState, index, field.c_str());
-	}
-
-	void set(const std::string& field, int index = GLOBALS)
-	{
-		lua_setfield(mState, index, field.c_str());
+		return Slot(*this, index);
 	}
 
 
@@ -920,8 +1033,10 @@ inline std::ostream& operator << (std::ostream& stream,
 	}
 	else if (slot.isBoolean())
 	{
-		if (slot) stream << "true";
-		else      stream << "false";
+		bool value;
+		slot.get(value);
+		if (value) stream << "true";
+		else       stream << "false";
 	}
 	else if (slot.isNil())
 	{
@@ -929,7 +1044,7 @@ inline std::ostream& operator << (std::ostream& stream,
 	}
 	else
 	{
-		stream << slot.getTypeName() << " (" << slot.getIdentifier() << ")";
+		stream << slot.typeName() << " (" << slot.id() << ")";
 	}
 
 	return stream;
diff --git a/src/Moof/Settings.cc b/src/Moof/Settings.cc
index bc503c5..5846430 100644
--- a/src/Moof/Settings.cc
+++ b/src/Moof/Settings.cc
@@ -27,7 +27,14 @@ void Settings::parseArgs(int argc, char* argv[])
 {
 	for (int i = 1; i < argc; ++i)
 	{
-		mScript.doString(argv[i]);
+		if (mScript.doString(argv[i]) != Script::SUCCESS)
+		{
+			std::string str;
+			mScript[-1].get(str);
+			logWarning << "invalid option: " << argv[i]
+					   << ": " << str << std::endl;
+			mScript.clearStack();
+		}
 	}
 }
 
@@ -72,7 +79,7 @@ void Settings::loadFromFiles(const std::vector<std::string>& path)
 			std::string str;
 			mScript[-1].get(str);
 			logWarning(str);
-			mScript.clear();
+			mScript.clearStack();
 		}
 	}
 }
diff --git a/src/Moof/Settings.hh b/src/Moof/Settings.hh
index 42ef70c..192e2a7 100644
--- a/src/Moof/Settings.hh
+++ b/src/Moof/Settings.hh
@@ -54,7 +54,7 @@ public:
 	void saveAs(const std::string& path);
 	void save() const;
 
-	template <typename T>
+	template <class T>
 	bool get(const std::string& key, T& value) const;
 
 private:
@@ -65,11 +65,11 @@ private:
 };
 
 
-template <typename T>
+template <class T>
 bool Settings::get(const std::string& key, T& value) const
 {
 	Script::Slot top = mScript[-1];
-	Script::Slot globals = mScript.getGlobalTable();
+	Script::Slot globals = mScript.globals();
 
 	std::vector<std::string> fields;
 	boost::split(fields, key, boost::is_any_of("."));
@@ -85,13 +85,13 @@ bool Settings::get(const std::string& key, T& value) const
 		}
 		else
 		{
-			mScript.clear();
+			mScript.clearStack();
 			return false;
 		}
 	}
 
 	bool got = top.get(value);
-	mScript.clear();
+	mScript.clearStack();
 	return got;
 }
 
diff --git a/src/Moof/Texture.cc b/src/Moof/Texture.cc
index 3ca067a..7f9f83c 100644
--- a/src/Moof/Texture.cc
+++ b/src/Moof/Texture.cc
@@ -89,20 +89,18 @@ class Texture::Impl : public Manager<Impl>
 	}
 
 
-	static void bindScriptConstants(Mf::Script& script)
+	static void bindScriptConstants(Script& script)
 	{
-		script.push(GL_CLAMP); script.set("CLAMP");
-		script.push(GL_REPEAT); script.set("REPEAT");
-		script.push(GL_LINEAR); script.set("LINEAR");
-		script.push(GL_NEAREST); script.set("NEAREST");
-		script.push(GL_LINEAR_MIPMAP_LINEAR);
-		script.set("LINEAR_MIPMAP_LINEAR");
-		script.push(GL_LINEAR_MIPMAP_NEAREST);
-		script.set("LINEAR_MIPMAP_NEAREST");
-		script.push(GL_NEAREST_MIPMAP_LINEAR);
-		script.set("NEAREST_MIPMAP_LINEAR");
-		script.push(GL_NEAREST_MIPMAP_NEAREST);
-		script.set("NEAREST_MIPMAP_NEAREST");
+		Script::Slot g = script.globals();
+
+		g.setField("CLAMP",   GL_CLAMP);
+		g.setField("REPEAT",  GL_REPEAT);
+		g.setField("LINEAR",  GL_LINEAR);
+		g.setField("NEAREST", GL_NEAREST);
+		g.setField("LINEAR_MIPMAP_LINEAR",   GL_LINEAR_MIPMAP_LINEAR);
+		g.setField("LINEAR_MIPMAP_NEAREST",  GL_LINEAR_MIPMAP_NEAREST);
+		g.setField("NEAREST_MIPMAP_LINEAR",  GL_NEAREST_MIPMAP_LINEAR);
+		g.setField("NEAREST_MIPMAP_NEAREST", GL_NEAREST_MIPMAP_NEAREST);
 	}
 
 public:
@@ -228,42 +226,29 @@ public:
 
 		mImage->flip();
 
-		Mf::Script script;
+		Script script;
 
 		importLogFunctions(script);
 		bindScriptConstants(script);
 
-		if (script.doString(mImage->getComment()) != Mf::Script::SUCCESS)
+		if (script.doString(mImage->getComment()) != Script::SUCCESS)
 		{
 			std::string str;
 			script[-1].get(str);
-			Mf::logWarning(str);
+			logWarning(str);
 		}
 		else
 		{
-			Mf::logInfo << "loading tiles from texture " << path
-						<< std::endl;
-
-			Mf::Script::Slot globals = script.getGlobalTable();
-			Mf::Script::Slot top = script[-1];
-
-			globals.pushField("tiles_s");
-			top.get(mTilesS);
-
-			globals.pushField("tiles_t");
-			top.get(mTilesT);
-
-			globals.pushField("min_filter");
-			top.get(mMinFilter);
-
-			globals.pushField("mag_filter");
-			top.get(mMagFilter);
-
-			globals.pushField("wrap_s");
-			top.get(mWrapS);
-
-			globals.pushField("wrap_t");
-			top.get(mWrapT);
+			logInfo << "loading tiles from texture " << path
+					<< std::endl;
+
+			Script::Slot globals = script.globals();
+			globals.get(mTilesS, "tiles_s");
+			globals.get(mTilesT, "tiles_t");
+			globals.get(mMinFilter, "min_filter");
+			globals.get(mMagFilter, "mag_filter");
+			globals.get(mWrapS, "wrap_s");
+			globals.get(mWrapT, "wrap_t");
 		}
 	}
 
diff --git a/src/Moof/Transition.hh b/src/Moof/Transition.hh
index 194caf5..2f468fc 100644
--- a/src/Moof/Transition.hh
+++ b/src/Moof/Transition.hh
@@ -27,7 +27,7 @@
 namespace Mf {
 
 
-template <typename T>
+template <class T>
 class Transition : public Layer
 {
 	LayerP	mTo;
diff --git a/src/Scene.cc b/src/Scene.cc
index 918ff52..16e1aef 100644
--- a/src/Scene.cc
+++ b/src/Scene.cc
@@ -177,19 +177,19 @@ struct Scene::Impl : public Mf::Manager<Impl>
 
 		int detail = 3;
 		settings.get("detail", detail);
-		script.push(detail); script.set("detail");
+		script.globals().setField("detail", detail);
 
-		script.push(1); script.set("LOW");
-		script.push(2); script.set("MEDIUM");
-		script.push(3); script.set("HIGH");
+		script.globals().setField("LOW",    1);
+		script.globals().setField("MEDIUM", 2);
+		script.globals().setField("HIGH",   3);
 
-		script.push(X); script.set("X");
-		script.push(Y); script.set("Y");
-		script.push(Z); script.set("Z");
+		script.globals().setField("X", X);
+		script.globals().setField("Y", Y);
+		script.globals().setField("Z", Z);
 
-		script.push(Quad::LEFT);  script.set("LEFT");
-		script.push(Quad::RIGHT); script.set("RIGHT");
-		script.push(Quad::TOP);   script.set("TOP");
+		script.globals().setField("LEFT",  Quad::LEFT);
+		script.globals().setField("RIGHT", Quad::RIGHT);
+		script.globals().setField("TOP",   Quad::TOP);
 	}
 
 
@@ -207,26 +207,17 @@ struct Scene::Impl : public Mf::Manager<Impl>
 	}
 
 
-	static int loadBox(Mf::Script& script, Mf::Aabb<3>& aabb)
+	static int loadBox(Mf::Script& script, Mf::Aabb3& aabb)
 	{
 		script[1].requireTable();
 		script[2].requireTable();
-		script.setSize(2);
 
-		for (int i = 1; i <= 2; ++i)
-		{
-			for (int j = 1; j <= 3; ++j)
-			{
-				script[i].pushField(j);
-			}
-		}
-
-		script[3].get(aabb.min[0]);
-		script[4].get(aabb.min[1]);
-		script[5].get(aabb.min[2]);
-		script[6].get(aabb.max[0]);
-		script[7].get(aabb.max[1]);
-		script[8].get(aabb.max[2]);
+		script[1].pushField(1).get(aabb.min[0]);
+		script[1].pushField(2).get(aabb.min[1]);
+		script[1].pushField(3).get(aabb.min[2]);
+		script[2].pushField(1).get(aabb.max[0]);
+		script[2].pushField(2).get(aabb.max[1]);
+		script[2].pushField(3).get(aabb.max[2]);
 
 		return 0;
 	}
@@ -247,7 +238,6 @@ struct Scene::Impl : public Mf::Manager<Impl>
 	int translate(Mf::Script& script)
 	{
 		Mf::Vector3 vec;
-
 		script[1].requireNumber().get(vec[0]);
 		script[2].requireNumber().get(vec[1]);
 		script[3].requireNumber().get(vec[2]);
@@ -261,7 +251,7 @@ struct Scene::Impl : public Mf::Manager<Impl>
 
 	int scale(Mf::Script& script)
 	{
-		int size = script.getSize();
+		int size = script.stackSize();
 
 		if (size == 1)
 		{
@@ -285,7 +275,7 @@ struct Scene::Impl : public Mf::Manager<Impl>
 		}
 		else
 		{
-			script.getTop().throwError("wrong number of arguments");
+			script.top().raise("wrong number of arguments");
 		}
 
 		return 0;
@@ -316,19 +306,16 @@ struct Scene::Impl : public Mf::Manager<Impl>
 		Mf::Script::Slot	table = script[1].requireTable();
 
 		int width  = 1;
-		int height = 1;
-		int nTiles = 0;
-
 		table.get(width, "width");
 
-		nTiles = table.getLength();
+		int nTiles = table.length();
 		if (nTiles % width != 0)
 		{
-			table.throwError("invalid number of tiles");
+			table.raise("invalid number of tiles");
 		}
 
-		if (width == 0) table.throwError("width field must not be zero");
-		height = nTiles / width;
+		if (width == 0) table.raise("width field must not be zero");
+		int height = nTiles / width;
 
 		Mf::Vector3		vertices[height+1][width+1];