From Mathias Froehlich, Integration of osgText::Font with QFont to enable use of Qt fonts and selectors in osgText.

include/osgQt/QFontImplementation

@@ -0,0 +1,48 @@
+/* -*-c++-*- OpenSceneGraph - Copyright (C) 2009-2010 Mathias Froehlich
+ *
+ * This library is open source and may be redistributed and/or modified under  
+ * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or 
+ * (at your option) any later version.  The full license is in LICENSE file
+ * included with this distribution, and on the openscenegraph.org website.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
+ * OpenSceneGraph Public License for more details.
+*/
+#ifndef QFontImplementation_H
+#define QFontImplementation_H
+
+#include <osgText/Font>
+#include <osgQt/Export>
+
+#include <QtGui/QFont>
+
+#include <string>
+
+namespace osgQt {
+
+class OSGQT_EXPORT QFontImplementation : public osgText::Font::FontImplementation
+{
+public:
+    QFontImplementation(const QFont& font);
+    virtual ~QFontImplementation();
+
+    virtual std::string getFileName() const;
+
+    void setFontResolution(const osgText::FontResolution& fontSize);
+    virtual osgText::Font::Glyph* getGlyph(const osgText::FontResolution& fontRes, unsigned int charcode);
+    virtual osg::Vec2 getKerning(const osgText::FontResolution& fontRes, unsigned int leftcharcode,
+                                 unsigned int rightcharcode, osgText::KerningType kerningType);
+    virtual bool hasVertical() const;
+
+protected:
+
+    std::string             _filename;
+    osgText::FontResolution _currentRes;
+    QFont                   _font;
+};
+
+}
+
+#endif

src/osgQt/CMakeLists.txt

@@ -17,6 +17,7 @@ QT4_WRAP_CPP( SOURCES_H_MOC ${SOURCES_H} )
 
 SET(LIB_PUBLIC_HEADERS
     ${HEADER_PATH}/Export
+    ${HEADER_PATH}/QFontImplementation
     ${HEADER_PATH}/QGraphicsViewAdapter
     ${HEADER_PATH}/QWebViewImage
 )
@@ -25,6 +26,7 @@ SET(LIB_PUBLIC_HEADERS
 ADD_LIBRARY(${LIB_NAME}
     ${OPENSCENEGRAPH_USER_DEFINED_DYNAMIC_OR_STATIC}
     ${LIB_PUBLIC_HEADERS}
+    QFontImplementation.cpp
     QGraphicsViewAdapter.cpp
     QWebViewImage.cpp
     ${SOURCES_H_MOC}

src/osgQt/QFontImplementation.cpp

@@ -0,0 +1,143 @@
+/* -*-c++-*- OpenSceneGraph - Copyright (C) 2009-2010 Mathias Froehlich
+ *
+ * This library is open source and may be redistributed and/or modified under  
+ * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or 
+ * (at your option) any later version.  The full license is in LICENSE file
+ * included with this distribution, and on the openscenegraph.org website.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
+ * OpenSceneGraph Public License for more details.
+*/
+#include <osgQt/QFontImplementation>
+
+#include <osgDB/FileNameUtils>
+#include <osgDB/Registry>
+#include <osgText/Font>
+
+#include <QtGui/QFont>
+#include <QtGui/QFontMetrics>
+#include <QtGui/QImage>
+#include <QtGui/QPainter>
+
+namespace osgQt {
+
+QFontImplementation::QFontImplementation(const QFont& font) :
+   _filename(font.toString().toStdString() + ".qfont"),
+   _font(font)
+{
+   _currentRes.first = 0;
+   _currentRes.second = 0;
+}
+
+QFontImplementation::~QFontImplementation()
+{
+}
+
+std::string
+QFontImplementation::getFileName() const
+{
+    return _filename;
+}
+
+void
+QFontImplementation::setFontResolution(const osgText::FontResolution& fontSize)
+{
+    if (fontSize == _currentRes)
+        return;
+
+    _currentRes = fontSize;
+    _font.setPixelSize(fontSize.second);
+}
+
+osgText::Font::Glyph*
+QFontImplementation::getGlyph(const osgText::FontResolution& fontRes, unsigned int charcode)
+{
+    setFontResolution(fontRes);
+
+    QFontMetrics fontMetrics(_font);
+    QFontMetricsF fontMetricsF(_font);
+
+    QRect rect = fontMetrics.boundingRect(QChar(charcode));
+    QRectF rectF = fontMetricsF.boundingRect(QChar(charcode));
+
+    int margin = 1;
+
+    int imageWidth = rect.width() + 2*margin;
+    int imageHeight = rect.height() + 2*margin;
+
+    // Now paint the glyph into the image
+    QImage image(imageWidth, imageHeight, QImage::Format_ARGB32);
+    image.fill(0);
+    QPainter painter(&image);
+    painter.setRenderHint(QPainter::TextAntialiasing);
+
+    painter.setFont(_font);
+
+    painter.setBackgroundMode(Qt::TransparentMode);
+    painter.setBrush(Qt::white);
+    painter.setPen(Qt::white);
+
+    painter.drawText(margin - rect.left(), imageHeight - 1 - (margin + rect.bottom()), QString(QChar(charcode)));
+    painter.end();
+
+    // Transfer the rendered image to osg
+    osg::ref_ptr<osgText::Font::Glyph> glyph = new osgText::Font::Glyph(charcode);
+
+    unsigned int dataSize = imageWidth*imageHeight;
+    unsigned char* data = new unsigned char[dataSize];
+
+    // copy the qimage into the texture memory
+    for (int x = 0; x < imageWidth; ++x)
+    {
+        for (int y = 0; y < imageHeight; ++y)
+        {
+           data[x + y*imageWidth] = qAlpha(image.pixel(x, imageHeight - 1 - y));
+        }
+    }
+    
+    // the glyph texture in osg
+    glyph->setImage(imageWidth, imageHeight, 1,
+                    GL_ALPHA,
+                    GL_ALPHA, GL_UNSIGNED_BYTE,
+                    data,
+                    osg::Image::USE_NEW_DELETE,
+                    1);
+    glyph->setInternalTextureFormat(GL_ALPHA);
+
+    // Layout parameters
+    float leftBearing = fontMetricsF.leftBearing(QChar(charcode));
+    float rightBearing = fontMetricsF.rightBearing(QChar(charcode));
+
+    // for horizonal layout
+    osg::Vec2 bottomLeft(leftBearing - margin, - rectF.bottom() - margin);
+    glyph->setHorizontalBearing(bottomLeft);
+    glyph->setHorizontalAdvance(fontMetricsF.width(QChar(charcode)));
+
+    // for vertical layout
+    osg::Vec2 topMiddle(- margin + 0.5*(leftBearing - rect.width() - rightBearing),
+                        rectF.top() - margin);
+    glyph->setVerticalBearing(topMiddle);
+    glyph->setVerticalAdvance(rectF.height() + fontMetricsF.overlinePos() - fontMetricsF.xHeight());
+    
+    // ... ready
+    addGlyph(fontRes, charcode, glyph.get());
+    
+    return glyph.release();
+}
+
+osg::Vec2
+QFontImplementation::getKerning(const osgText::FontResolution& fontRes, unsigned int leftcharcode,
+                                unsigned int rightcharcode, osgText::KerningType kerningType)
+{
+    return osg::Vec2(0, 0);
+}
+
+bool
+QFontImplementation::hasVertical() const
+{
+    return true;
+}
+
+}