/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 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_TEXTBASE
#define OSGTEXT_TEXTBASE 1

#include <osg/Drawable>

#include <osgText/String>
#include <osgText/KerningType>

namespace osgText {


class OSGTEXT_EXPORT TextBase : public osg::Drawable
{
public:

    TextBase();
    TextBase(const TextBase& text,const osg::CopyOp& copyop=osg::CopyOp::SHALLOW_COPY);

    //virtual osg::Object* cloneType() const { return new Text(); }
    //virtual osg::Object* clone(const osg::CopyOp& copyop) const { return new Text(*this,copyop); }
    virtual bool isSameKindAs(const osg::Object* obj) const { return dynamic_cast<const TextBase*>(obj)!=NULL; }
    virtual const char* className() const { return "TextBase"; }
    virtual const char* libraryName() const { return "osgText"; }

    
    /** Set the Font reference width and height resolution in texels.
      * Note, the size may not be supported by current font, 
      * the closest supported font size will be selected.*/
    void setFontResolution(unsigned int width, unsigned int height);

    unsigned int getFontWidth() const { return _fontSize.first; }
    unsigned int getFontHeight() const { return _fontSize.second; }
    
    
    /** Set the text using a osgText::String.*/
    void setText(const String& text);

    /** Set the text using a std::string, 
      * which is converted to an internal TextString.*/
    void setText(const std::string& text);

    /** Set the text using a Unicode encoded std::string, which is converted to an internal TextString.
      * The encoding parameter specificies which Unicode encodeding is used in the std::string. */
    void setText(const std::string& text,String::Encoding encoding);

    /** Set the text using a wchar_t string, 
      * which is converted to an internal TextString.*/
    void setText(const wchar_t* text);
    
    /** Get the text string. 
      * Note, if you modify the string you must call Text::update() for
      * the internal glyph reprentation to be updated.*/
    String& getText() { return _text; }

    /** Get the const text string.*/
    const String& getText() const { return _text; }
    
    /** update internal glyph respresentation used for rendering, 
      * and bounding volume.*/
    void update() { computeGlyphRepresentation(); }


    /** Set the rendered character size in object coordinates.*/
    void setCharacterSize(float height,float aspectRatio=1.0f);
    
    float getCharacterHeight() const { return _characterHeight; }
    float getCharacterAspectRatio() const { return _characterAspectRatio; }

    enum CharacterSizeMode
    {
        OBJECT_COORDS, /// default
        SCREEN_COORDS, /// internally scale the characters to be constant screen size.
        OBJECT_COORDS_WITH_MAXIMUM_SCREEN_SIZE_CAPPED_BY_FONT_HEIGHT /// text that behavaves like OBJECT_COORDS sized text when a long distance way, but has its screen sized capped automatically when the viewer gets near.
    };

    /** Set how the CharacterSize value relates to the final rendered character.*/
    void setCharacterSizeMode(CharacterSizeMode mode) { _characterSizeMode = mode; }
    
    /** Get the CharacterSizeMode.*/
    CharacterSizeMode getCharacterSizeMode() const { return _characterSizeMode; }


    /** Set the maximum width of the text box.
      * With horizontal layouts any characters which do not fit are wrapped around.
      * 0 or negative values indicate that no maximum width is set, lines can be as long as 
      * they need be to fit thre required text*/
    void setMaximumWidth(float maximumWidth);
    
    /** Get the maximim width of the text box.*/
    float getMaximumWidth() const { return _maximumWidth; }

    /** Set the maximum height of the text box.
      * With horizontal layouts any characters which do not fit are wrapped around.
      * 0 or negative values indicate that no maximum height is set, lines can be as long as 
      * they need be to fit the required text*/
    void setMaximumHeight(float maximumHeight);
    
    /** Get the maximum height of the text box.*/
    float getMaximumHeight() const { return _maximumHeight; }

    /** Set the line spacing of the text box, given as a percentage of
      * the character height. The default value is 0 for backward 
      * compatibility. For longer paragraphs of text, a value of at 
      * least 25% (i.e. set line spacing to 0.25) is recommended. */
    void setLineSpacing(float lineSpacing);

    /** Get the line spacing of the text box. */
    float getLineSpacing() const { return _lineSpacing; }



    /** Set the position of text.*/
    void setPosition(const osg::Vec3& pos);
    
    /** Get the position of text.*/
    const osg::Vec3& getPosition() const { return _position; }
    

    enum AlignmentType
    {
        LEFT_TOP,
        LEFT_CENTER,
        LEFT_BOTTOM,

        CENTER_TOP,
        CENTER_CENTER,
        CENTER_BOTTOM,

        RIGHT_TOP,
        RIGHT_CENTER,
        RIGHT_BOTTOM,
        
        LEFT_BASE_LINE,
        CENTER_BASE_LINE,
        RIGHT_BASE_LINE,
    
        LEFT_BOTTOM_BASE_LINE,
        CENTER_BOTTOM_BASE_LINE,
        RIGHT_BOTTOM_BASE_LINE,
    
        BASE_LINE = LEFT_BASE_LINE /// default.
    
    };
    
    void setAlignment(AlignmentType alignment);
    AlignmentType getAlignment() const { return _alignment; }


    enum AxisAlignment
    {
        XY_PLANE,
        REVERSED_XY_PLANE,
        XZ_PLANE,
        REVERSED_XZ_PLANE,
        YZ_PLANE,
        REVERSED_YZ_PLANE,
        SCREEN,
        USER_DEFINED_ROTATION
    };

    void setAxisAlignment(AxisAlignment axis);
    AxisAlignment getAxisAlignment() const { return _axisAlignment; }
    
    void setRotation(const osg::Quat& quat);
    const osg::Quat& getRotation() const { return _rotation; }

    void setAutoRotateToScreen(bool autoRotateToScreen);
    bool getAutoRotateToScreen() const { return _autoRotateToScreen; }

    enum Layout
    {
        LEFT_TO_RIGHT, /// default
        RIGHT_TO_LEFT,
        VERTICAL
    };
    
    void setLayout(Layout layout);
    
    Layout getLayout() const { return _layout; }


    enum DrawModeMask
    {
        TEXT        = 1, /// default
        BOUNDINGBOX = 2,
        ALIGNMENT   = 4
    };

    void setDrawMode(unsigned int mode);
    
    unsigned int getDrawMode() const { return _drawMode; }

    
    void setKerningType(KerningType kerningType) { _kerningType = kerningType; }

    KerningType getKerningType() const { return _kerningType; }

    /** Get the number of wrapped lines - only valid after computeGlyphRepresentation() has been called, returns 0 otherwise */
    unsigned int getLineCount() const { return _lineCount; }

    /** 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);

    /** If State is non-zero, this function releases OpenGL objects for
      * the specified graphics context. Otherwise, releases OpenGL objexts
      * for all graphics contexts. */
    virtual void releaseGLObjects(osg::State* state=0) const;

    
    virtual osg::BoundingBox computeBound() const;

protected:

    virtual ~TextBase();

    void positionCursor(const osg::Vec2 & endOfLine_coords, osg::Vec2 & cursor, unsigned int linelength);
    void computePositions();
    String::iterator computeLastCharacterOnLine(osg::Vec2& cursor, String::iterator first,String::iterator last);


    virtual void computePositions(unsigned int contextID) const = 0;
    virtual void computeGlyphRepresentation() = 0;
    
    
    // members which have public access.
    FontResolution                          _fontSize;
    float                                   _characterHeight;
    float                                   _characterAspectRatio;
    CharacterSizeMode                       _characterSizeMode;
    float                                   _maximumWidth;
    float                                   _maximumHeight;
    float                                   _lineSpacing;

    String                                  _text;
    osg::Vec3                               _position;
    AlignmentType                           _alignment;
    AxisAlignment                           _axisAlignment;
    osg::Quat                               _rotation;
    bool                                    _autoRotateToScreen;
    Layout                                  _layout;
    unsigned int                            _drawMode;
    KerningType                             _kerningType;
    unsigned int                            _lineCount;

    

    // internal caches of the positioning of the text.
    
    struct AutoTransformCache
    {    
        AutoTransformCache():
            _traversalNumber(-1),
            _width(0),
            _height(0) {}
    
        int         _traversalNumber;
        int         _width;
        int         _height;
        osg::Vec3   _transformedPosition;
        osg::Matrix _modelview;
        osg::Matrix _projection;
        osg::Matrix _matrix;
    };
    
    mutable osg::buffered_object<AutoTransformCache>    _autoTransformCache;
    mutable osg::Vec3                                   _offset;
    mutable osg::Vec3                                   _normal;
    mutable osg::BoundingBox                            _textBB;
};

}


#endif
 
