Changed the osgText::Font implementation so it used a facade us abstract away

the actual implemention. This has been done so that when a freetype font is
created the implementation can unloaded when the freetype plugin is unloaded
without breaking the main font.

Also add image margin around founds to prevent any image boundaries appearing.

src/osgText/Font.cpp

@@ -75,23 +75,69 @@ osgText::Font* osgText::readFontFile(const std::string& filename)
 }
 
 
-Font::Font():
+Font::Font(FontImplementation* implementation):
     _width(16),
-    _height(16)
+    _height(16),
+    _margin(2),
+    _textureWidthHint(256),
+    _textureHeightHint(256),
+    _minFilterHint(osg::Texture::LINEAR_MIPMAP_LINEAR),
+    _magFilterHint(osg::Texture::LINEAR)
 {
+    setImplementation(implementation);
 }
 
 Font::~Font()
 {
-    for(TextList::iterator itr=_textList.begin();
-        itr!=_textList.end();
-        ++itr)
-    {
-        Text* text = *itr;
-        text->_font.release();
-    }
+    if (_implementation.valid()) _implementation->_facade = 0;
 }
 
+void Font::setImplementation(FontImplementation* implementation)
+{
+    if (_implementation.valid()) _implementation->_facade = 0;
+    _implementation = implementation;
+    if (_implementation.valid()) _implementation->_facade = this;
+}
+
+std::string Font::getFileName() const
+{
+    if (_implementation.valid()) return _implementation->getFileName();
+    return "";
+}
+
+void Font::setSize(unsigned int width, unsigned int height)
+{
+    if (_implementation.valid()) return _implementation->setSize(width, height);
+}
+
+Font::Glyph* Font::getGlyph(unsigned int charcode)
+{
+    SizeGlyphMap::iterator itr = _sizeGlyphMap.find(SizePair(_width,_height));
+    if (itr!=_sizeGlyphMap.end())
+    {
+        GlyphMap& glyphmap = itr->second;    
+        GlyphMap::iterator gitr = glyphmap.find(charcode);
+        if (gitr!=glyphmap.end()) return gitr->second.get();
+    }
+
+    if (_implementation.valid()) return _implementation->getGlyph(charcode);
+    else return 0;
+}
+
+osg::Vec2 Font::getKerning(unsigned int leftcharcode,unsigned int rightcharcode)
+{
+    if (_implementation.valid()) return _implementation->getKerning(leftcharcode,rightcharcode);
+    else return osg::Vec2(0.0f,0.0f);
+}
+
+bool Font::hasVertical() const
+{
+    if (_implementation.valid()) return _implementation->hasVertical();
+    else return false;
+}
+
+
+
 void Font::addGlyph(unsigned int width, unsigned int height, unsigned int charcode, Glyph* glyph)
 {
     _sizeGlyphMap[SizePair(width,height)][charcode]=glyph;
@@ -115,13 +161,12 @@ void Font::addGlyph(unsigned int width, unsigned int height, unsigned int charco
         _stateSetList.push_back(stateset);
 
         glyphTexture = new GlyphTexture;
-        
+
         // reserve enough space for the glyphs.
-        glyphTexture->setTextureSize(256,256);
-        glyphTexture->setFilter(osg::Texture::MIN_FILTER,osg::Texture::LINEAR);
-        glyphTexture->setFilter(osg::Texture::MIN_FILTER,osg::Texture::LINEAR_MIPMAP_LINEAR);
-        //glyphTexture->setFilter(osg::Texture::MAG_FILTER,osg::Texture::NEAREST);
-        glyphTexture->setFilter(osg::Texture::MAG_FILTER,osg::Texture::LINEAR);
+        glyphTexture->setGlyphImageMargin(_margin);
+        glyphTexture->setTextureSize(_textureWidthHint,_textureHeightHint);
+        glyphTexture->setFilter(osg::Texture::MIN_FILTER,_minFilterHint);
+        glyphTexture->setFilter(osg::Texture::MAG_FILTER,_magFilterHint);
         glyphTexture->setMaxAnisotropy(8);
         
         _glyphTextureList.push_back(glyphTexture);
@@ -147,6 +192,7 @@ void Font::addGlyph(unsigned int width, unsigned int height, unsigned int charco
 
 Font::GlyphTexture::GlyphTexture():
     _stateset(0),
+    _margin(2),
     _usedY(0),
     _partUsedX(0),
     _partUsedY(0)
@@ -159,11 +205,9 @@ Font::GlyphTexture::~GlyphTexture()
 
 bool Font::GlyphTexture::getSpaceForGlyph(Glyph* glyph, int& posX, int& posY)
 {
-
-    int margin = 2;
         
-    int width = glyph->s()+2*margin;
-    int height = glyph->t()+2*margin;
+    int width = glyph->s()+2*_margin;
+    int height = glyph->t()+2*_margin;
 
     // first check box (_partUsedX,_usedY) to (width,height)
     if (width <= (getTextureWidth()-_partUsedX) &&
@@ -172,8 +216,8 @@ bool Font::GlyphTexture::getSpaceForGlyph(Glyph* glyph, int& posX, int& posY)
         // can fit in existing row.
 
         // record the position in which the texture will be stored.
-        posX = _partUsedX+margin;
-        posY = _usedY+margin;        
+        posX = _partUsedX+_margin;
+        posY = _usedY+_margin;        
 
         // move used markers on.
         _partUsedX += width;
@@ -190,8 +234,8 @@ bool Font::GlyphTexture::getSpaceForGlyph(Glyph* glyph, int& posX, int& posY)
         _partUsedX = 0;
         _usedY = _partUsedY;
 
-        posX = _partUsedX+margin;
-        posY = _usedY+margin;        
+        posX = _partUsedX+_margin;
+        posY = _usedY+_margin;        
 
         // move used markers on.
         _partUsedX += width;
@@ -216,8 +260,8 @@ void Font::GlyphTexture::addGlyph(Glyph* glyph, int posX, int posY)
     // set up the details of where to place glyph's image in the texture.
     glyph->setTexture(this);
     glyph->setTexturePosition(posX,posY);
-    glyph->setMinTexCoord(osg::Vec2(((float)posX-1.0f)/((float)getTextureWidth()-1.0f),((float)posY-1)/((float)getTextureHeight()-1.0f)));
-    glyph->setMaxTexCoord(osg::Vec2((float)(posX+glyph->s())/((float)getTextureWidth()-1.0f),(float)(posY+glyph->t())/((float)getTextureHeight()-1.0f)));
+    glyph->setMinTexCoord(osg::Vec2((float)(posX+_margin)/(float)(getTextureWidth()-1),(float)(posY+_margin)/(float)(getTextureHeight()-1)));
+    glyph->setMaxTexCoord(osg::Vec2((float)(posX+glyph->s()-_margin)/(float)(getTextureWidth()-1),(float)(posY+glyph->t()-_margin)/(float)(getTextureHeight()-1)));
 }
 
 void Font::GlyphTexture::apply(osg::State& state) const