Drop textures when no longer needed

Textures used to be unloaded as soon as they were unreferenced.
The TextureMgr cache keeps an active reference to prevent load-unload-load
cycles so it only unloads things when explicitly asked.
This does require some more peak VRAM during map/tileset transitions
especially, since old textures are unloaded only after the next map
has been loaded, but the shortened load times should be worth it.

Aquaria/Game.cpp

@@ -3219,6 +3219,9 @@ void Game::applyState()
 	// cutscenes immediately.  --achurch
 	dsq->subtitlePlayer.show(0.25);
 
+	// First cleanup -- we're now done loading everything; anything leftover from the prev. map can go
+	dsq->texmgr.clearUnused();
+
 	if (verbose) debugLog("loading map init script");
 	if (dsq->mod.isActive())
 		dsq->runScript(dsq->mod.getPath() + "scripts/map_" + sceneName + ".lua", "init", true);
@@ -3264,6 +3267,10 @@ void Game::applyState()
 		dsq->toggleCursor(true, 0.5);
 	}
 
+	// Second cleanup -- after the short map init fadeout, some entities may have
+	// decided to remove themselves, in which case their gfx are no longer needed
+	dsq->texmgr.clearUnused();
+
 	debugLog("Game::applyState Done");
 }
 

BBGE/Refcounted.h

@@ -29,6 +29,10 @@ public:
 		if (!--_refcount)
 			delete this;
 	}
+	inline unsigned refcount() const
+	{
+		return _refcount;
+	}
 
 private:
 	unsigned _refcount;

BBGE/TextureMgr.cpp

@@ -166,6 +166,24 @@ Texture* TextureMgr::getOrLoad(const std::string& name)
     return load(name, KEEP);
 }
 
+void TextureMgr::clearUnused()
+{
+    size_t done = 0;
+    for(TexCache::iterator it = cache.begin(); it != cache.end(); )
+    {
+        if(it->second->refcount() <= 1)
+        {
+            it = cache.erase(it);
+            ++done;
+        }
+        else
+            ++it;
+    }
+    std::ostringstream os;
+    os << "TextureMgr: Dropped " << done << " unused textures, now " << cache.size() << " left";
+    debugLog(os.str());
+}
+
 void TextureMgr::shutdown()
 {
     for(TexCache::iterator it = cache.begin(); it != cache.end(); ++it)