X-Git-Url: http://git.tdb.fi/?p=libs%2Fgl.git;a=blobdiff_plain;f=source%2Fbindable.h;h=b2634ea92bd4b1b43bb1f88b502af230f1e3c4bd;hp=e26840fa3950e977b309beeeeeca96bb3ee33e6e;hb=4b4d2a48048268d2ad48bafbce8647af8088573f;hpb=b617c5d7b5283ad260a77f01e42e6170cabbc03d

diff --git a/source/bindable.h b/source/bindable.h
index e26840fa..b2634ea9 100644
--- a/source/bindable.h
+++ b/source/bindable.h
@@ -1,16 +1,13 @@
-/* $Id$
-
-This file is part of libmspgl
-Copyright © 2010  Mikko Rasa, Mikkosoft Productions
-Distributed under the LGPL
-*/
-
 #ifndef MSP_GL_BINDABLE_H_
 #define MSP_GL_BINDABLE_H_
 
 namespace Msp {
 namespace GL {
 
+/**
+A helper class for single-point binding.  Provides tracking of the currently
+bound object.
+*/
 template<typename T>
 class Bindable
 {
@@ -18,6 +15,7 @@ protected:
 	static const T *cur_obj;
 
 	Bindable() { }
+	~Bindable() { if(cur_obj==this) T::unbind(); }
 
 	static bool set_current(const T *obj)
 	{
@@ -29,13 +27,47 @@ protected:
 	}
 
 public:
-	const T *current() const { return cur_obj; }
+	static const T *current() { return cur_obj; }
 };
 
 template<typename T>
 const T *Bindable<T>::cur_obj;
 
 
+/**
+A helper class for Bindables that revert to a default object on unbind.
+*/
+template<typename T>
+class BindableWithDefault: protected Bindable<T>
+{
+	friend class Bindable<T>;
+
+protected:
+	BindableWithDefault() { }
+	~BindableWithDefault() { if(this==&default_object()) Bindable<T>::set_current(0); }
+
+public:
+	static const T *current()
+	{
+		if(!Bindable<T>::cur_obj)
+			Bindable<T>::cur_obj = &default_object();
+		return Bindable<T>::cur_obj;
+	}
+
+	static void unbind()
+	{
+		if(Bindable<T>::cur_obj)
+			default_object().bind();
+	}
+
+	static const T &default_object()
+	{
+		static T obj;
+		return obj;
+	}
+};
+
+
 /**
 RAII class for binding things.  Binds the thing upon construction and unbinds
 it upon destruction.  If a null pointer is given, unbinds upon construction and
@@ -44,35 +76,147 @@ does nothing upon destruction.
 class Bind
 {
 private:
-	struct Base
-	{
-		virtual ~Base() { }
-	};
+	typedef void CleanupFunc(int);
+
+	int slot;
+	CleanupFunc *cleanup;
+
+public:
+	template<typename T>
+	Bind(T *o) { init(o); }
+
+	template<typename T>
+	Bind(const T *o) { init(o); }
+
+	template<typename T>
+	Bind(const T &o) { init(&o); }
+
+	template<typename T, typename S>
+	Bind(T *o, S s) { init(o, s); }
+
+	template<typename T, typename S>
+	Bind(const T *o, S s) { init(o, s); }
+
+	template<typename T, typename S>
+	Bind(const T &o, S s) { init(&o, s); }
 
+private:
 	template<typename T>
-	struct Binder: Base
+	void init(const T *o)
 	{
-		const T &obj;
+		cleanup = (o ? static_cast<CleanupFunc *>(&unbind<T>) : 0);
+		slot = 0;
+		if(o)
+			o->bind();
+		else
+			T::unbind();
+	}
+
+	template<typename T, typename S>
+	void init(const T *o, S s)
+	{
+		cleanup = (o ? static_cast<CleanupFunc *>(&unbind_from<T, S>) : 0);
+		slot = s;
+		if(o)
+			o->bind_to(s);
+		else
+			T::unbind_from(s);
+	}
+
+public:
+	~Bind()
+	{ if(cleanup) cleanup(slot); }
+
+private:
+	template<typename T>
+	static void unbind(int)
+	{ T::unbind(); }
 
-		Binder(const T &o): obj(o) { obj.bind(); }
-		~Binder() { obj.unbind(); }
-	};
+	template<typename T, typename S>
+	static void unbind_from(int s)
+	{ T::unbind_from(static_cast<S>(s)); }
+};
 
-	Base *binder;
+
+/**
+Similar to Bind, but restores previous binding upon destruction.
+*/
+class BindRestore
+{
+private:
+	typedef void CleanupFunc(const void *, int);
+
+	const void *old;
+	int slot;
+	CleanupFunc *cleanup;
 
 public:
 	template<typename T>
-	Bind(const T &o): binder(new Binder<T>(o)) { }
+	BindRestore(T *o) { init(o); }
+
+	template<typename T>
+	BindRestore(const T *o) { init(o); }
 
 	template<typename T>
-	Bind(const T *o): binder(o ? new Binder<T>(*o) : 0) { if(!o) T::unbind(); }
+	BindRestore(const T &o) { init(&o); }
+
+	template<typename T, typename S>
+	BindRestore(T *o, S s) { init(o, s); }
+
+	template<typename T, typename S>
+	BindRestore(const T *o, S s) { init(o, s); }
+
+	template<typename T, typename S>
+	BindRestore(const T &o, S s) { init(&o, s); }
 
 private:
-	Bind(const Bind &);
-	Bind &operator=(const Bind &);
+	template<typename T>
+	void init(T *o)
+	{
+		old = T::current();
+		slot = 0;
+		cleanup = (o!=old ? static_cast<CleanupFunc *>(&restore<T>) : 0);
+		if(o)
+			o->bind();
+		else if(old)
+			T::unbind();
+	}
+
+	template<typename T, typename S>
+	void init(T *o, S s)
+	{
+		old = T::current(s);
+		slot = s;
+		cleanup = (o!=old ? static_cast<CleanupFunc *>(&restore_to<T, S>) : 0);
+		if(o)
+			o->bind_to(s);
+		else if(old)
+			T::unbind_from(s);
+	}
 
 public:
-	~Bind() { delete binder; }
+	~BindRestore()
+	{ if(cleanup) cleanup(old, slot); }
+
+private:
+	template<typename T>
+	static void restore(const void *o, int)
+	{
+		if(o)
+			reinterpret_cast<const T *>(o)->bind();
+		else
+			T::unbind();
+	}
+
+	template<typename T, typename S>
+	static void restore_to(const void *o, int si)
+	{
+		S s = static_cast<S>(si);
+		if(o)
+			reinterpret_cast<const T *>(o)->bind_to(s);
+		else
+			T::unbind_from(s);
+	}
 };
 
 } // namespace GL