include/FTGL/FTLibrary.h

0001 /*
0002  * FTGL - OpenGL font library
0003  *
0004  * Copyright (c) 2001-2004 Henry Maddocks <ftgl@opengl.geek.nz>
0005  *
0006  * Permission is hereby granted, free of charge, to any person obtaining
0007  * a copy of this software and associated documentation files (the
0008  * "Software"), to deal in the Software without restriction, including
0009  * without limitation the rights to use, copy, modify, merge, publish,
0010  * distribute, sublicense, and/or sell copies of the Software, and to
0011  * permit persons to whom the Software is furnished to do so, subject to
0012  * the following conditions:
0013  *
0014  * The above copyright notice and this permission notice shall be
0015  * included in all copies or substantial portions of the Software.
0016  *
0017  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
0018  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
0019  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
0020  * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
0021  * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
0022  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
0023  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
0024  */
0025
0026 #ifndef     __FTLibrary__
0027 #define     __FTLibrary__
0028
0029 #ifdef __cplusplus
0030
0031 #include <ft2build.h>
0032 #include FT_FREETYPE_H
0033 //#include FT_CACHE_H
0034
0035 #include "FTGL/ftgl.h"
0036 #include <atomic>
0037
0038 /**
0039  * FTLibrary class is the global accessor for the Freetype library.
0040  *
0041  * This class encapsulates the Freetype Library. This is a singleton class
0042  * and ensures that only one FT_Library is in existence at any one time.
0043  * All constructors are private therefore clients cannot create or
0044  * instantiate this class themselves and must access it's methods via the
0045  * static <code>FTLibrary::Instance()</code> function.
0046  *
0047  * Just because this class returns a valid <code>FTLibrary</code> object
0048  * doesn't mean that the Freetype Library has been successfully initialised.
0049  * Clients should check for errors. You can initialise the library AND check
0050  * for errors using the following code...
0051  * <code>err = FTLibrary::Instance().Error();</code>
0052  *
0053  * @see "Freetype 2 Documentation"
0054  *
0055  */
0056 class FTLibrary
0057 {
0058     public:
0059         /**
0060          * Global acces point to the single FTLibrary object.
0061          *
0062          * @return  The global <code>FTLibrary</code> object.
0063          */
0064         static FTLibrary& Instance();
0065
0066         /**
0067          * Gets a pointer to the native Freetype library.
0068          *
0069          * @return A handle to a FreeType library instance.
0070          */
0071         const FT_Library* GetLibrary() const { return library; }
0072
0073         /**
0074          * Queries the library for errors.
0075          *
0076          * @return  The current error code.
0077          */
0078         FT_Error Error() const { return err; }
0079
0080         /**
0081          * Destructor
0082          *
0083          * Disposes of the Freetype library
0084          */
0085         ~FTLibrary();
0086
0087         /**
0088          * See README-LegacyOpenGLState
0089          *
0090          * Choose incompatible legacy behaviour, see commit
0091          * 29603ae3fa88c5b9e079a6db23be2cdea95aef39.
0092          *
0093          * May only be set to the same value (but any number of times)
0094          * within one program.
0095          */
0096         void LegacyOpenGLState(bool On);
0097         bool GetLegacyOpenGLStateSet() const { return LegacyOpenGLStateHandling; }
0098
0099     private:
0100         /**
0101          * Default constructors.
0102          *
0103          * Made private to stop clients creating their own FTLibrary
0104          * objects.
0105          */
0106         FTLibrary();
0107         FTLibrary(const FT_Library&){}
0108         FTLibrary& operator=(const FT_Library&) { return *this; }
0109
0110         /**
0111          * Initialises the Freetype library
0112          *
0113          * Even though this function indicates success via the return value,
0114          * clients can't see this so must check the error codes. This function
0115          * is only ever called by the default c_stor
0116          *
0117          * @return  <code>true</code> if the Freetype library was
0118          *          successfully initialised, <code>false</code>
0119          *          otherwise.
0120          */
0121         bool Initialise();
0122
0123         /**
0124          * Freetype library handle.
0125          */
0126         FT_Library* library;
0127 //      FTC_Manager* manager;
0128
0129         /**
0130          * Current error code. Zero means no error.
0131          */
0132         FT_Error err;
0133
0134         /**
0135          * Flag set by LegacyOpenGLState, -1 means implicitly on (default).
0136          */
0137         std::atomic <int> LegacyOpenGLStateHandling;
0138 };
0139
0140 #endif //__cplusplus
0141
0142 #endif  //  __FTLibrary__