Optimise TrueTypeFont::getWidth

Use the cache created by TTF::drawString, drops the cost of
TTF::getWidth from 5% of runtime to 0.5%.

It increases the cost of calculating line-wrapping in the BrowserBox,
but overall it's a saving, even with the BrowserBox recalculating on
every redraw.

2 files changed, 19 insertions, 1 deletions

diff --git a/src/gui/truetypefont.cpp b/src/gui/truetypefont.cpp
index 5243a175..fe507489 100644
--- a/src/gui/truetypefont.cpp
+++ b/src/gui/truetypefont.cpp
@@ -1,6 +1,7 @@
 /*
  *  The Mana World
  *  Copyright (C) 2004-2010  The Mana World Development Team
+ *  Copyright (C) 2009  Aethyra Development Team
  *
  *  This file is part of The Mana World.
  *
@@ -42,6 +43,11 @@ class TextChunk
             delete img;
         }
 
+        bool operator==(const std::string &str) const
+        {
+            return (str == text);
+        }
+
         bool operator==(const TextChunk &chunk) const
         {
             return (chunk.text == text && chunk.color == color);
@@ -162,6 +168,17 @@ void TrueTypeFont::drawString(gcn::Graphics *graphics,
 
 int TrueTypeFont::getWidth(const std::string &text) const
 {
+    for (CacheIterator i = mCache.begin(); i != mCache.end(); i++)
+    {
+        if ((*i) == text)
+        {
+            // Raise priority: move it to front
+            // Assumption is that TTF::draw will be called next
+            mCache.splice(mCache.begin(), mCache, i);
+            return i->img->getWidth();
+        }
+    }
+
     int w, h;
     TTF_SizeUTF8(mFont, text.c_str(), &w, &h);
     return w;
diff --git a/src/gui/truetypefont.h b/src/gui/truetypefont.h
index 9211a7dc..45e1ec70 100644
--- a/src/gui/truetypefont.h
+++ b/src/gui/truetypefont.h
@@ -1,6 +1,7 @@
 /*
  *  The Mana World
  *  Copyright (C) 2004-2010  The Mana World Development Team
+ *  Copyright (C) 2009  Aethyra Development Team
  *
  *  This file is part of The Mana World.
  *
@@ -75,7 +76,7 @@ class TrueTypeFont : public gcn::Font
         TTF_Font *mFont;
 
         // Word surfaces cache
-        std::list<TextChunk> mCache;
+        mutable std::list<TextChunk> mCache;
 };
 
 #endif