#ifndef    __FTFace__
#define    __FTFace__

#include "FTGL.h"

#include <vtk_freetype.h>
#include FT_FREETYPE_H
#include FT_GLYPH_H

#include "FTSize.h"

class FTCharmap;

/**
 * FTFace class provides an abstraction layer for the Freetype Face.
 *
 * @see  "Freetype 2 Documentation - 2.0.4"
 *
 */
class FTGL_EXPORT FTFace
{
  public:
    /**
     * Default Constructor
     */
    FTFace();

    /**
     * Destructor
     *
     * Disposes of the current Freetype Face.
     */
    virtual ~FTFace();

    /**
     * Opens and reads a face file.
     *
     * @param fontname  font file name.
     * @return      <code>true</code> if file has opened
     *          successfully.
     */
    bool Open( const char* filename);

    /**
     * Read face data from an in-memory buffer.
     *
     * @param pBufferBytes  the in-memory buffer
     * @param bufferSizeInBytes  the length of the buffer in bytes
     * @return      <code>true</code> if file has opened
     *          successfully.
     */
    bool Open( const unsigned char *pBufferBytes, size_t bufferSizeInBytes );

    /** 
     * Attach auxiliary file to face (e.g., font metrics). 
     */ 
    bool Attach( const char* filename); 

    /**
     * Disposes of the face
     */
    void Close();
    
    /**
     * Sets the char size for the current face.
     *
     * This doesn't guarantee that the size was set correctly. Clients
     * should check errors.
     *
     * @param size    the face size in points (1/72 inch)
     * @param res    the resolution of the target device.
     * @return      <code>FTSize</code> object
     */
    FTSize& Size( const unsigned int size, const unsigned int res);

    /**
     * Sets the character map for the face.
     *
     * This doesn't guarantee that the size was set correctly. Clients
     * should check errors.
     *
     * @param encoding    the Freetype encoding symbol. See above.
     * @return        <code>true</code> if charmap was valid
     *            and set correctly
     */
    bool CharMap( FT_Encoding encoding);

    /**
     *  Get the glyph index of the input character.
     *
     * @param index The character code of the requested glyph in the
     *        current encoding eg apple roman.
     * @return    The glyph index for the character.
     */
    unsigned int CharIndex( unsigned int index ) const;

    /**
     * Gets the kerning vector between two glyphs
     */
    FT_Vector& KernAdvance( unsigned int index1, unsigned int index2);

    /**
     * Loads and creates a Freetype glyph.
     */
    FT_Glyph* Glyph( unsigned int index, FT_Int load_flags);

    /**
     * Gets the current Freetype face.
     */
    FT_Face* Face() { return &ftFace;}

    /**
     * Queries for errors.
     *
     * @return  The current error code.
     */
    FT_Error Error() const { return err; }
    
  private:
    /**
     * The size object associated with this face
     */
    FTSize  charSize;
    
    /**
     * The Character Map object associated with this face
     */
    FTCharmap* charMap;

    /**
     * The Freetype face
     */
    FT_Face ftFace;

    /**
     * Temporary variable to hold a glyph
     */
    FT_Glyph ftGlyph;

    /**
     * The number of character maps in this face.
     */
    int  numCharMaps;

    /**
     * The number of glyphs in this face
     */
    int  numGlyphs;

    /**
     * Temporary variable to holding a kerning vector.
     */
    FT_Vector kernAdvance;
    
    /**
     * Current error code. Zero means no error.
     */
    FT_Error err;
};


#endif  //  __FTFace__
