From: Mikko Rasa <tdb@tdb.fi>
Date: Sat, 11 Jan 2014 18:05:15 +0000 (+0200)
Subject: Reuse meshes in PartCache to avoid buffer create/delete spam
X-Git-Url: http://git.tdb.fi/?p=libs%2Fgltk.git;a=commitdiff_plain;h=2a665655a15f73d59083fd5cc7e5a58ae5f4d377

Reuse meshes in PartCache to avoid buffer create/delete spam
---

diff --git a/source/partcache.cpp b/source/partcache.cpp
index 5589b0d..4747cb5 100644
--- a/source/partcache.cpp
+++ b/source/partcache.cpp
@@ -18,9 +18,10 @@ CachedPart::~CachedPart()
 }
 
 
-void PartCache::clear()
+void PartCache::begin_rebuild()
 {
-	parts.clear();
+	next = parts.begin();
+	current = parts.end();
 }
 
 void PartCache::insert_special(const Part &part)
@@ -28,21 +29,54 @@ void PartCache::insert_special(const Part &part)
 	if(part.get_name().empty())
 		throw invalid_argument("PartCache::insert_special");
 
-	parts.push_back(CachedPart());
-	parts.back().part = &part;
+	for(current=next; current!=parts.end(); ++current)
+		if(current->part==&part)
+		{
+			parts.erase(next, current);
+			break;
+		}
+
+	if(current==parts.end())
+		current = parts.insert(next, CachedPart());
+	else
+		*current = CachedPart();
+	current->part = &part;
+
+	next = current;
+	++next;
 }
 
 GL::Mesh &PartCache::create_mesh(const Part &part, const GL::Texture2D &tex)
 {
-	if(!parts.empty() && parts.back().texture==&tex)
-		return *parts.back().mesh;
-
-	parts.push_back(CachedPart());
-	CachedPart &cpart = parts.back();
-	cpart.part = &part;
-	cpart.texture = &tex;
-	cpart.mesh = new GL::Mesh((GL::TEXCOORD2, GL::COLOR4_UBYTE, GL::VERTEX2));
-	return *cpart.mesh;
+	if(current!=parts.end() && current->texture==&tex)
+		return *current->mesh;
+
+	for(current=next; current!=parts.end(); ++current)
+		if(current->texture==&tex)
+		{
+			parts.erase(next, current);
+			break;
+		}
+
+	if(current==parts.end())
+	{
+		current = parts.insert(next, CachedPart());
+		current->texture = &tex;
+		current->mesh = new GL::Mesh((GL::TEXCOORD2, GL::COLOR4_UBYTE, GL::VERTEX2));
+	}
+	else
+		current->mesh->clear();
+	current->part = &part;
+
+	next = current;
+	++next;
+
+	return *current->mesh;
+}
+
+void PartCache::end_rebuild()
+{
+	parts.erase(next, parts.end());
 }
 
 } // namespace GLtk
diff --git a/source/partcache.h b/source/partcache.h
index 86a3f36..90d1c94 100644
--- a/source/partcache.h
+++ b/source/partcache.h
@@ -26,11 +26,14 @@ public:
 
 private:
 	PartList parts;
+	PartList::iterator next;
+	PartList::iterator current;
 
 public:
-	void clear();
+	void begin_rebuild();
 	void insert_special(const Part &);
 	GL::Mesh &create_mesh(const Part &, const GL::Texture2D &);
+	void end_rebuild();
 
 	const PartList &get_parts() const { return parts; }
 };
diff --git a/source/widget.cpp b/source/widget.cpp
index 8b7f1cb..76b6e61 100644
--- a/source/widget.cpp
+++ b/source/widget.cpp
@@ -193,7 +193,7 @@ void Widget::rebuild()
 	if(!style)
 		return;
 
-	part_cache.clear();
+	part_cache.begin_rebuild();
 	const Style::PartSeq &parts = style->get_parts();
 	for(Style::PartSeq::const_iterator i=parts.begin(); i!=parts.end(); ++i)
 	{
@@ -202,6 +202,7 @@ void Widget::rebuild()
 		else
 			rebuild_special(*i);
 	}
+	part_cache.end_rebuild();
 }
 
 void Widget::rebuild_special(const Part &part)