/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2010 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_GLYPH
#define OSGTEXT_GLYPH 1

#include <string>
#include <istream>

#include <osg/Vec2>
#include <osg/Image>
#include <osg/Texture2D>
#include <osg/StateSet>
#include <osg/Geometry>
#include <osg/Geode>

#include <osgText/Export>
#include <osgText/KerningType>
#include <osgText/Style>

#include <OpenThreads/Mutex>

// GL_ALPHA is deprecated in GL3/GL4 core profile, use GL_RED and a shader in this case. See osgText example.
#if defined(OSG_GL3_AVAILABLE) && !defined(OSG_GL2_AVAILABLE) && !defined(OSG_GL1_AVAILABLE)
#define OSGTEXT_GLYPH_FORMAT GL_RED
#define OSGTEXT_GLYPH_INTERNALFORMAT GL_R8
#else
#define OSGTEXT_GLYPH_FORMAT GL_ALPHA
#define OSGTEXT_GLYPH_INTERNALFORMAT GL_ALPHA
#endif

namespace osgText {

class Font;
class Text;
class Glyph3D;
class GlyphGeometry;
class GlyphTexture;

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

    Glyph(Font* font, unsigned int glyphCode);

    Font* getFont() { return _font; }
    const Font* getFont() const { return _font; }

    unsigned int getGlyphCode() const { return _glyphCode; }

    void setWidth(float width) { _width = width; }
    float getWidth() const { return _width; }

    void setHeight(float height) { _height = height; }
    float getHeight() const { return _height; }

    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;

    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:

    virtual ~Glyph();

    Font*                       _font;
    unsigned int                _glyphCode;

    float                       _width;
    float                       _height;

    osg::Vec2                   _horizontalBearing;
    float                       _horizontalAdvance;

    osg::Vec2                   _verticalBearing;
    float                       _verticalAdvance;

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

    typedef osg::buffered_value<GLuint> GLObjectList;
    mutable GLObjectList _globjList;

};

class OSGTEXT_EXPORT GlyphGeometry : public osg::Referenced
{
    public:

        GlyphGeometry();

        void setup(const Glyph3D* glyph, const Style* style);

        bool match(const Style* style) const;

        osg::Geode* getGeode() const { return _geode.get(); }
        osg::Geometry* getGeometry() const { return _geometry.get(); }

        /** Set the VertexArray of the glyph. */
        void setVertexArray(osg::Vec3Array * va) { _vertices = va; }
        /** Get the VertexArray of the glyph. */
        osg::Vec3Array * getVertexArray() const { return _vertices.get(); }

        /** Set the VertexArray of the glyph. */
        void setNormalArray(osg::Vec3Array* na) { _normals = na; }
        /** Get the NormalArray for the wall face. */
        osg::Vec3Array* getNormalArray() const { return _normals.get(); }

        /** Get the PrimitiveSetList for the front face. */
        osg::Geometry::PrimitiveSetList& getFrontPrimitiveSetList() { return _frontPrimitiveSetList; }
        /** Get the PrimitiveSetList for the wall face. */
        osg::Geometry::PrimitiveSetList& getWallPrimitiveSetList() { return _wallPrimitiveSetList; }
        /** Get et the PrimitiveSetList for the back face. */
        osg::Geometry::PrimitiveSetList& getBackPrimitiveSetList() { return _backPrimitiveSetList; }

        /** Set whether to use a mutex to ensure ref() and unref() are thread safe.*/
        virtual void setThreadSafeRefUnref(bool threadSafe);

    protected:

        osg::ref_ptr<Style>             _style;
        osg::ref_ptr<osg::Geode>        _geode;
        osg::ref_ptr<osg::Geometry>     _geometry;
        osg::ref_ptr<osg::Vec3Array>    _vertices;
        osg::ref_ptr<osg::Vec3Array>    _normals;

        osg::Geometry::PrimitiveSetList _frontPrimitiveSetList;
        osg::Geometry::PrimitiveSetList _wallPrimitiveSetList;
        osg::Geometry::PrimitiveSetList _backPrimitiveSetList;
};


class OSGTEXT_EXPORT Glyph3D : public osg::Referenced
{
public:

    Glyph3D(Font* font, unsigned int glyphCode);

    Font* getFont() { return _font; }
    const Font* getFont() const { return _font; }

    unsigned int getGlyphCode() const { return _glyphCode; }

    void setWidth(float width) { _width = width; }
    float getWidth() const { return _width; }

    void setHeight(float height) { _height = height; }
    float getHeight() const { return _height; }

    void setHorizontalBearing(const osg::Vec2& bearing) { _horizontalBearing=bearing; }
    const osg::Vec2 & getHorizontalBearing() const { return _horizontalBearing; }

    void setHorizontalAdvance(float advance) { _horizontalAdvance=advance; }
    float getHorizontalAdvance() const { return _horizontalAdvance; }

    void setVerticalBearing(const osg::Vec2& bearing) {  _verticalBearing=bearing; }
    const osg::Vec2& getVerticalBearing() const { return _verticalBearing; }

    void setVerticalAdvance(float advance) { _verticalAdvance=advance; }
    float getVerticalAdvance() const { return _verticalAdvance; }

    void setBoundingBox(osg::BoundingBox & bb) { _bb=bb; }
    const osg::BoundingBox & getBoundingBox() const { return _bb; }


    /** Set whether to use a mutex to ensure ref() and unref() are thread safe.*/
    virtual void setThreadSafeRefUnref(bool threadSafe);


    void setRawVertexArray(osg::Vec3Array* vertices) { _rawVertexArray = vertices; }
    osg::Vec3Array* getRawVertexArray() { return _rawVertexArray.get(); }
    const osg::Vec3Array* getRawVertexArray() const { return _rawVertexArray.get(); }

    /** Get the PrimitiveSetList for the raw face which hasn't been tessellated. */
    osg::Geometry::PrimitiveSetList & getRawFacePrimitiveSetList() { return _rawFacePrimitiveSetList; }
    const osg::Geometry::PrimitiveSetList & getRawFacePrimitiveSetList() const { return _rawFacePrimitiveSetList; }

    GlyphGeometry* getGlyphGeometry(const Style* style);

protected:

    virtual ~Glyph3D() {}

    Font*                       _font;
    unsigned int                _glyphCode;

    float                       _width;
    float                       _height;

    osg::Vec2                   _horizontalBearing;
    float                       _horizontalAdvance;

    osg::Vec2                   _verticalBearing;
    float                       _verticalAdvance;

    osg::BoundingBox            _bb;
//        osg::Vec2                   _advance;


    osg::ref_ptr<osg::Vec3Array>    _rawVertexArray;
    osg::Geometry::PrimitiveSetList _rawFacePrimitiveSetList;

    typedef std::list< osg::ref_ptr<GlyphGeometry> >  GlyphGeometries;
    GlyphGeometries _glyphGeometries;

};


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

    GlyphTexture();

    const char* className() const { return "GlyphTexture"; }

    /** return -1 if *this < *rhs, 0 if *this==*rhs, 1 if *this>*rhs.*/
    virtual int compare(const osg::StateAttribute& rhs) const;

    /** Set the margin around each glyph, to ensure that texture filtering doesn't bleed adjacent glyph's into each other.*/
    void setGlyphImageMargin(unsigned int margin) { _margin = margin; }
    unsigned int getGlyphImageMargin() const { return _margin; }

    void setGlyphImageMarginRatio(float margin) { _marginRatio = margin; }
    float getGlyphImageMarginRatio() const { return _marginRatio; }

    bool getSpaceForGlyph(Glyph* glyph, int& posX, int& posY);

    void addGlyph(Glyph* glyph,int posX, int posY);

    /** Set whether to use a mutex to ensure ref() and unref() are thread safe.*/
    virtual void setThreadSafeRefUnref(bool threadSafe);

    /** Resize any per context GLObject buffers to specified size. */
    virtual void resizeGLObjectBuffers(unsigned int maxSize);

    /** create an image that maps all the associated Glyph's onto a single image, that is equivalent to what will be downloaded to the texture.*/
    osg::Image* createImage();

protected:

    virtual ~GlyphTexture();


    // parameter used to compute the size and position of empty space
    // in the texture which could accommodate new glyphs.
    int _margin;
    float _marginRatio;
    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;

    mutable OpenThreads::Mutex  _mutex;

};

}


#endif