From bb48cef38cd3ab0f4e59c19ba493804290d9a3b1 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Mon, 3 Oct 2011 10:36:18 +0000
Subject: [PATCH] Added Font::getVertical(float& ascender, float& descender)
 methods.

---
 include/osgText/Font                     |  8 ++++-
 src/osgPlugins/freetype/FreeTypeFont.cpp | 45 +++++++++++++++++++-----
 src/osgPlugins/freetype/FreeTypeFont.h   |  4 +++
 3 files changed, 48 insertions(+), 9 deletions(-)

diff --git a/include/osgText/Font b/include/osgText/Font
index 39b96410a..90af2cb36 100644
--- a/include/osgText/Font
+++ b/include/osgText/Font
@@ -104,7 +104,11 @@ public:
     /** Return true if this font provides vertical alignments and spacing or glyphs.*/
     virtual bool hasVertical() const;
 
-    /** Set the margin around each glyph, 
+    /** Get the ascender and descender sizes of the font where supported by the FontImplementation,
+     *  return true on success, return false when not supported.*/
+    virtual bool getVerticalSize(float& ascender, float& descender) const { return _implementation ? _implementation->getVerticalSize(ascender, descender) : false; }
+
+    /** Set the margin around each glyph,
       * to ensure that texture filtering doesn't bleed adjacent glyph's into each other.
       * Default margin is 1 texels.*/    
     void setGlyphImageMargin(unsigned int margin);
@@ -236,6 +240,8 @@ public:
         }
 
         Font* _facade;
+
+        virtual bool getVerticalSize(float & ascender, float & descender) const { return false; }
     };
 
 
diff --git a/src/osgPlugins/freetype/FreeTypeFont.cpp b/src/osgPlugins/freetype/FreeTypeFont.cpp
index 23b3c7d8f..a4fb749af 100644
--- a/src/osgPlugins/freetype/FreeTypeFont.cpp
+++ b/src/osgPlugins/freetype/FreeTypeFont.cpp
@@ -299,7 +299,7 @@ osgText::Glyph* FreeTypeFont::getGlyph(const osgText::FontResolution& fontRes, u
 
     setFontResolution(fontRes);
 
-    float coord_scale = 1.0f/(float(_currentRes.second)*64.0f);
+    float coord_scale = getCoordScale();
 
     //
     // GT: fix for symbol fonts (i.e. the Webdings font) as the wrong character are being  
@@ -394,13 +394,15 @@ osgText::Glyph* FreeTypeFont::getGlyph(const osgText::FontResolution& fontRes, u
     glyph->setVerticalAdvance((float)metrics->vertAdvance * coord_scale);
 
 #if 0
-    OSG_NOTICE<<"getGlyph("<<charcode<<", "<<char(charcode)<<")"<<std::endl;
+    OSG_NOTICE<<"getGlyph("<<charcode<<", "<<char(charcode)<<") _face="<<_face<<", _filename="<<_filename<<std::endl;
     OSG_NOTICE<<"   height="<<glyph->getHeight()<<std::endl;
     OSG_NOTICE<<"   width="<<glyph->getWidth()<<std::endl;
     OSG_NOTICE<<"   horizontalBearing="<<glyph->getHorizontalBearing()<<std::endl;
     OSG_NOTICE<<"   horizontalAdvance="<<glyph->getHorizontalAdvance()<<std::endl;
     OSG_NOTICE<<"   verticalBearing="<<glyph->getHorizontalBearing()<<std::endl;
     OSG_NOTICE<<"   verticalAdvance="<<glyph->getVerticalAdvance()<<std::endl;
+    OSG_NOTICE<<"   coord_scale = "<<coord_scale<<std::endl;
+    OSG_NOTICE<<"   _face->units_per_EM = "<<_face->units_per_EM<<", scale="<<1.0f/float(_face->units_per_EM)<<std::endl;
 #endif
     
 //    cout << "      in getGlyph() implementation="<<this<<"  "<<_filename<<"  facade="<<_facade<<endl;
@@ -440,9 +442,7 @@ osgText::Glyph3D * FreeTypeFont::getGlyph3D(unsigned int charcode)
         return 0;
     }
 
-    //float coord_scale = _freetype_scale/64.0f;
-    //float coord_scale = (1.0f/float(fontDPI))/64.0f;
-    float coord_scale = 1.0f/(float(_currentRes.second)*64.0f);
+    float coord_scale = getCoordScale();
 
     // ** init FreeType to describe the glyph
     FreeType::Char3DInfo char3d(_facade->getNumberCurveSamples());
@@ -540,9 +540,7 @@ osg::Vec2 FreeTypeFont::getKerning(unsigned int leftcharcode,unsigned int rightc
         return osg::Vec2(0.0f,0.0f);
     }
 
-    //float coord_scale = _freetype_scale/64.0f;
-    //float coord_scale = 1.0f/64.0f;
-    float coord_scale = 1.0f/(float(_currentRes.second)*64.0f);
+    float coord_scale = getCoordScale();
 
     return osg::Vec2((float)kerning.x*coord_scale,(float)kerning.y*coord_scale);
 }
@@ -552,3 +550,34 @@ bool FreeTypeFont::hasVertical() const
     OpenThreads::ScopedLock<OpenThreads::Mutex> lock(FreeTypeLibrary::instance()->getMutex());
     return FT_HAS_VERTICAL(_face)!=0;
 }
+
+bool FreeTypeFont::getVerticalSize(float & ascender, float & descender) const
+{
+    OpenThreads::ScopedLock<OpenThreads::Mutex> lock(FreeTypeLibrary::instance()->getMutex());
+#if 1
+    if(_face->units_per_EM != 0)
+    {
+        float coord_scale = 1.0f/static_cast<float>(_face->units_per_EM);
+        ascender = static_cast<float>(_face->ascender) * coord_scale;
+        descender = static_cast<float>(_face->descender) * coord_scale;
+        return true;
+    }
+    else
+    {
+        return false;
+    }
+#else
+    float coord_scale = getCoordScale();
+    ascender = static_cast<float>(_face->ascender) * coord_scale;
+    descender = static_cast<float>(_face->descender) * coord_scale;
+    return true;
+#endif
+} 
+
+float FreeTypeFont::getCoordScale() const
+{
+    //float coord_scale = _freetype_scale/64.0f;
+    //float coord_scale = 1.0f/64.0f;
+    float coord_scale = 1.0f/(float(_currentRes.second)*64.0f);
+    return coord_scale;
+}
diff --git a/src/osgPlugins/freetype/FreeTypeFont.h b/src/osgPlugins/freetype/FreeTypeFont.h
index f71ebf0dd..d8ab7df48 100644
--- a/src/osgPlugins/freetype/FreeTypeFont.h
+++ b/src/osgPlugins/freetype/FreeTypeFont.h
@@ -41,6 +41,10 @@ public:
 
     virtual bool hasVertical() const;
 
+    virtual bool getVerticalSize(float & ascender, float & descender) const;
+
+    float getCoordScale() const;
+    
 protected:
 
     void init();