/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2003 Robert Osfield 
 *
 * 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 OSGTEXT_FONT
#define OSGTEXT_FONT 1

#include <osg/Vec2>
#include <osg/Image>
#include <osg/Texture2D>
#include <osg/StateSet>
#include <osg/buffered_value>

#include <osgText/Export>

#include <string>

namespace osgText {

class Font;

/** read a font from specified file.*/
extern OSGTEXT_EXPORT Font* readFontFile(const std::string& filename);


/** Pure virtual base class for fonts.
  * Concrete implementation are the DefaultFont found in src/osgText/DefaultFont.cpp
  * and FreeTypeFont found in src/osgPlugins/freetype/FreeTypeFont.cpp*/
class OSGTEXT_EXPORT Font : public osg::Object
{
// declare the interface to a font.
public:

    // forward declare nested classes.
    class Glyph;
    class GlyphTexture;

    Font();

    virtual osg::Object* cloneType() const { return 0; } // cloneType() not appropriate
    virtual osg::Object* clone(const osg::CopyOp&) const { return 0; } // clone() not appropriate
    virtual bool isSameKindAs(const osg::Object* obj) const { return dynamic_cast<const Font*>(obj)!=NULL; }
    virtual const char* className() const { return "Font"; }
    virtual const char* libraryName() const { return "osgText"; }

    virtual std::string getFileName() const = 0;

    /** Set the pixel width and height */
    virtual void setSize(unsigned int width, unsigned int height) = 0;
    
    unsigned int getWidth() { return _width; }
    unsigned int getHeight() { return _height; }

    virtual Glyph* getGlyph(unsigned int charcode) = 0;
    
    virtual osg::Vec2 getKerning(unsigned int leftcharcode,unsigned int rightcharcode) = 0;
    
    virtual bool hasVertical() const = 0;


protected:

    virtual ~Font();
    
    void addGlyph(unsigned int charcode, Glyph* glyph);
    
    typedef std::vector< osg::ref_ptr<GlyphTexture> >       GlyphTextureList;
    typedef std::vector< osg::ref_ptr<osg::StateSet> >      StateSetList;
    typedef std::map< unsigned int, osg::ref_ptr<Glyph> >   GlyphMap;
    
    GlyphMap            _glyphMap;
    GlyphTextureList    _glyphTextureList;
    StateSetList        _stateSetList;
    
    // current active size of font
    unsigned int _width;
    unsigned int _height;

    
// declare the nested classes.
public:

    class OSGTEXT_EXPORT GlyphTexture : public osg::Texture2D
    {
    public:

        GlyphTexture();

        void setStateSet(osg::StateSet* stateset) { _stateset = stateset; }
        osg::StateSet* getStateSet() { return _stateset; }
        const osg::StateSet* getStateSet() const { return _stateset; }

        bool getSpaceForGlyph(Glyph* glyph, int& posX, int& posY);
        
        void addGlyph(Glyph* glyph,int posX, int posY);
        
        virtual void apply(osg::State& state) const;

    protected:
    
        virtual ~GlyphTexture();

        osg::StateSet* _stateset;
        
        // parameter used to compute the size and position of empty space
        // in the texture which could accomodate new glyphs.
        int _usedY;
        int _partUsedX;
        int _partUsedY;

        typedef std::vector< osg::ref_ptr<Glyph> > GlyphRefList;
        typedef std::vector< const Glyph* > GlyphPtrList;
        typedef osg::buffered_object< GlyphPtrList > GlyphBuffer;
        
        GlyphRefList        _glyphs;
        mutable GlyphBuffer _glyphsToSubload;

    };

    class OSGTEXT_EXPORT Glyph : public osg::Image
    {
    public:

        Glyph();
        virtual ~Glyph();

        unsigned int getGlyphCode() const;

        void setFont(Font* font);
        Font* getFont() const;

        void setHorizontalBearing(const osg::Vec2& bearing);
        const osg::Vec2& getHorizontalBearing() const;

        void setHorizontalAdvance(float advance);
        float getHorizontalAdvance() const;

        void setVerticalBearing(const osg::Vec2& bearing);
        const osg::Vec2& getVerticalBearing() const;

        void setVerticalAdvance(float advance);
        float getVerticalAdvance() const;


        void setTexture(GlyphTexture* texture);
        GlyphTexture* getTexture();
        const GlyphTexture* getTexture() const;

        osg::StateSet* getStateSet();
        const osg::StateSet* getStateSet() const;

        void setTexturePosition(int posX,int posY);
        int getTexturePositionX() const;
        int getTexturePositionY() const;

        void setMinTexCoord(const osg::Vec2& coord);
        const osg::Vec2& getMinTexCoord() const;

        void setMaxTexCoord(const osg::Vec2& coord);
        const osg::Vec2& getMaxTexCoord() const;
        
        void subload() const;

    protected:

        Font*                       _font;
        unsigned int                _glyphCode;

        osg::Vec2                   _horizontalBearing;
        float                       _horizontalAdvance;

        osg::Vec2                   _verticalBearing;
        float                       _verticalAdvance;

        GlyphTexture*               _texture;
        int                         _texturePosX;
        int                         _texturePosY;
        osg::Vec2                   _minTexCoord;
        osg::Vec2                   _maxTexCoord;

    };


};

}


#endif