Added proper handling of freeing of font implememtation either when unloading

the freetype plugin or deleting osgText::Font first.

src/osgPlugins/freetype/FreeTypeFont.cpp

@@ -12,6 +12,7 @@
 */
 
 #include "FreeTypeFont.h"
+#include "FreeTypeLibrary.h"
 
 #include <osg/Notify>  
 #include <osgDB/WriteFile>
@@ -24,11 +25,20 @@ FreeTypeFont::FreeTypeFont(const std::string& filename, FT_Face face):
 
 FreeTypeFont::~FreeTypeFont()
 {
-   if(_face)
-   {
-      FT_Done_Face(_face);
-      _face = 0;
-   }
+    if(_face)
+    {
+        FreeTypeLibrary* freeTypeLibrary = FreeTypeLibrary::instance();
+        if (freeTypeLibrary)
+        {
+            // remove myself from the local regsitry to ensure that
+            // not dangling pointers remain
+            freeTypeLibrary->removeFontImplmentation(this);
+        
+            // free the freetype font face itself
+            FT_Done_Face(_face);
+            _face = 0;
+        }
+    }
 }
 
 void FreeTypeFont::setFontResolution(unsigned int width, unsigned int height)

src/osgPlugins/freetype/FreeTypeFont.h

@@ -34,7 +34,7 @@ public:
 
     virtual osgText::Font::Glyph* getGlyph(unsigned int charcode);
     
-	virtual osg::Vec2 getKerning(unsigned int leftcharcode,unsigned int rightcharcode, osgText::KerningType _kerningType);
+    virtual osg::Vec2 getKerning(unsigned int leftcharcode,unsigned int rightcharcode, osgText::KerningType _kerningType);
     
     virtual bool hasVertical() const;
 

src/osgPlugins/freetype/FreeTypeLibrary.cpp

@@ -26,38 +26,31 @@ FreeTypeLibrary::FreeTypeLibrary()
 
 FreeTypeLibrary::~FreeTypeLibrary()
 {
-#ifdef USE_LOCAL_CACHE
     // need to remove the implementations from the Fonts here
     // just in case the Fonts continue to have external references
     // to them, otherwise they will try to point to an object thats
     // definiation has been unloaded along with the unload of the FreeType
     // plugin.
-    for(FontMap::iterator itr=_fontMap.begin();
-        itr!=_fontMap.end();
-        ++itr)
+    while(!_fontImplementationSet.empty())
     {
-        osgText::Font* font = itr->second.get();
+        FreeTypeFont* fontImplementation = *_fontImplementationSet.begin();
+        _fontImplementationSet.erase(_fontImplementationSet.begin());
+        osgText::Font* font = fontImplementation->_facade;
         font->setImplementation(0);
     }
-#endif
     
     FT_Done_FreeType( _ftlibrary);
 }
 
 FreeTypeLibrary* FreeTypeLibrary::instance()
 {
-    static FreeTypeLibrary s_library;
-    return &s_library;
+    static osg::ref_ptr<FreeTypeLibrary> s_library = new FreeTypeLibrary;
+    return s_library.get();
 }
 
 osgText::Font* FreeTypeLibrary::getFont(const std::string& fontfile,unsigned int index)
 {
 
-#ifdef USE_LOCAL_CACHE
-    FontMap::iterator itr = _fontMap.find(fontfile);
-    if (itr!=_fontMap.end()) return itr->second.get();
-#endif
-
     FT_Face face;      /* handle to face object */
     FT_Error error = FT_New_Face( _ftlibrary, fontfile.c_str(), index, &face );
     if (error == FT_Err_Unknown_File_Format)
@@ -76,9 +69,7 @@ osgText::Font* FreeTypeLibrary::getFont(const std::string& fontfile,unsigned int
     FreeTypeFont* fontImp = new FreeTypeFont(fontfile,face);
     osgText::Font* font = new osgText::Font(fontImp);
 
-#ifdef USE_LOCAL_CACHE
-    _fontMap[fontfile]=font;
-#endif
+    _fontImplementationSet.insert(fontImp);
     
     return font;
 

src/osgPlugins/freetype/FreeTypeLibrary.h

@@ -16,10 +16,9 @@
 
 #include "FreeTypeFont.h"
 #include <osgText/Font>
+#include <set>
 
-//#define USE_LOCAL_CACHE
-
-class FreeTypeLibrary
+class FreeTypeLibrary : public osg::Referenced
 {
 public:
 
@@ -30,6 +29,8 @@ public:
     static FreeTypeLibrary* instance();
 
     osgText::Font* getFont(const std::string& fontfile,unsigned int index=0);
+    
+    void removeFontImplmentation(FreeTypeFont* fontImpl) { _fontImplementationSet.erase(fontImpl); }
 
 protected:
 
@@ -37,14 +38,11 @@ protected:
       * library is via the singleton instance method.*/
     FreeTypeLibrary();
 
-    typedef std::map< std::string, osg::ref_ptr<osgText::Font> > FontMap;
+    typedef std::set< FreeTypeFont* > FontImplementationSet;
 
 
-    FT_Library  _ftlibrary;
-
-#ifdef USE_LOCAL_CACHE
-    FontMap     _fontMap;
-#endif
+    FT_Library              _ftlibrary;
+    FontImplementationSet   _fontImplementationSet;
 
 };
 

src/osgPlugins/freetype/ReaderWriterFreeType.cpp

@@ -1,6 +1,7 @@
 #include <osgDB/FileNameUtils>
 #include <osgDB/FileUtils>
 #include <osgDB/Registry>
+#include <osg/Notify>
 
 #include "FreeTypeLibrary.h"
 
@@ -30,9 +31,14 @@ class ReaderWriterFreeType : public osgDB::ReaderWriter
             std::string fileName = osgDB::findDataFile( file, options );
             if (fileName.empty()) return ReadResult::FILE_NOT_FOUND;
             
-            osgText::Font* font = FreeTypeLibrary::instance()->getFont(fileName,0);
-            
-            return font;
+            FreeTypeLibrary* freeTypeLibrary = FreeTypeLibrary::instance();
+            if (!freeTypeLibrary) 
+            {
+                osg::notify(osg::WARN)<<"Warning:: cannot create freetype font after freetype library has been deleted."<<std::endl;
+                return ReadResult::ERROR_IN_READING_FILE;
+            }
+
+            return freeTypeLibrary->getFont(fileName,0);
         }
 };