ftlibrary.h

ftgl-2.1.2 夸平台的opengl显示字体

#ifndef     __FTLibrary__
#define     __FTLibrary__

#include <ft2build.h>
#include FT_FREETYPE_H
//#include FT_CACHE_H

#include "FTGL.h"


/**
 * FTLibrary class is the global accessor for the Freetype library.
 *
 * This class encapsulates the Freetype Library. This is a singleton class
 * and ensures that only one FT_Library is in existence at any one time.
 * All constructors are private therefore clients cannot create or
 * instantiate this class themselves and must access it's methods via the
 * static <code>FTLibrary::Instance()</code> function.
 *
 * Just because this class returns a valid <code>FTLibrary</code> object
 * doesn't mean that the Freetype Library has been successfully initialised.
 * Clients should check for errors. You can initialse the library AND check
 * for errors using the following code...
 * <code>err = FTLibrary::Instance().Error();</code>
 *
 * @see "Freetype 2 Documentation"
 *
 */
class FTGL_EXPORT FTLibrary
{
    public:
        /**
         * Global acces point to the single FTLibrary object.
         * 
         * @return  The global <code>FTLibrary</code> object.
         */
        static const FTLibrary& Instance();

        /**
         * Gets a pointer to the native Freetype library.
         * 
         * @return A handle to a FreeType library instance. 
         */
        const FT_Library* const GetLibrary() const { return library;}
        
        /**
         * Queries the library for errors.
         *
         * @return  The current error code.
         */
        FT_Error Error() const { return err;}
        
        /**
         * Destructor
         *
         * Disposes of the Freetype library
         */
        ~FTLibrary();
        
    private:
        /**
         * Default constructors.
         *
         * Made private to stop clients creating there own FTLibrary
         * objects.
         */
        FTLibrary();
        FTLibrary( const FT_Library&){}
        FTLibrary& operator=( const FT_Library&) { return *this; }
        
        /**
         * Initialises the Freetype library
         *
         * Even though this function indicates success via the return value,
         * clients can't see this so must check the error codes. This function
         * is only ever called by the default c_stor
         *
         * @return  <code>true</code> if the Freetype library was
         *          successfully initialised, <code>false</code>
         *          otherwise.
         */
        bool Initialise();
        
        /**
         * Freetype library handle.
         */
        FT_Library* library;
//      FTC_Manager* manager;

        /**
         * Current error code. Zero means no error.
         */
        FT_Error err;
        
};

#endif  //  __FTLibrary__