path: root/src/ftgl/FTGL/FTFont.h

/*
 * FTGL - OpenGL font library
 *
 * Copyright (c) 2001-2004 Henry Maddocks <ftgl@opengl.geek.nz>
 * Copyright (c) 2008 Sam Hocevar <sam@zoy.org>
 * Copyright (c) 2008 Sean Morrison <learner@brlcad.org>
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#ifndef __ftgl__
#   warning This header is deprecated. Please use <FTGL/ftgl.h> from now.
#   include <FTGL/ftgl.h>
#endif

#ifndef __FTFont__
#define __FTFont__

#ifdef __cplusplus

class FTFontImpl;

/**
 * FTFont is the public interface for the FTGL library.
 *
 * Specific font classes are derived from this class. It uses the helper
 * classes FTFace and FTSize to access the Freetype library. This class
 * is abstract and deriving classes must implement the protected
 * <code>MakeGlyph</code> function to create glyphs of the
 * appropriate type.
 *
 * It is good practice after using these functions to test the error
 * code returned. <code>FT_Error Error()</code>. Check the freetype file
 * fterrdef.h for error definitions.
 *
 * @see     FTFace
 * @see     FTSize
 */
class FTGL_EXPORT FTFont
{
    protected:
        /**
         * Open and read a font file. Sets Error flag.
         *
         * @param fontFilePath  font file path.
         */
        FTFont(char const *fontFilePath);

        /**
         * Open and read a font from a buffer in memory. Sets Error flag.
         * The buffer is owned by the client and is NOT copied by FTGL. The
         * pointer must be valid while using FTGL.
         *
         * @param pBufferBytes  the in-memory buffer
         * @param bufferSizeInBytes  the length of the buffer in bytes
         */
        FTFont(const unsigned char *pBufferBytes, size_t bufferSizeInBytes);

    private:
        /* Allow our internal subclasses to access the private constructor */
        friend class FTBitmapFont;
        friend class FTBufferFont;
        friend class FTExtrudeFont;
        friend class FTOutlineFont;
        friend class FTPixmapFont;
        friend class FTPolygonFont;
        friend class FTTextureFont;

        /**
         * Internal FTGL FTFont constructor. For private use only.
         *
         * @param pImpl  Internal implementation object. Will be destroyed
         *               upon FTFont deletion.
         */
        FTFont(FTFontImpl *pImpl);

    public:
        virtual ~FTFont();

        /**
         * Attach auxilliary file to font e.g font metrics.
         *
         * Note: not all font formats implement this function.
         *
         * @param fontFilePath  auxilliary font file path.
         * @return          <code>true</code> if file has been attached
         *                  successfully.
         */
        virtual bool Attach(const char* fontFilePath);

        /**
         * Attach auxilliary data to font e.g font metrics, from memory.
         *
         * Note: not all font formats implement this function.
         *
         * @param pBufferBytes  the in-memory buffer.
         * @param bufferSizeInBytes  the length of the buffer in bytes.
         * @return          <code>true</code> if file has been attached
         *                  successfully.
         */
        virtual bool Attach(const unsigned char *pBufferBytes,
                            size_t bufferSizeInBytes);

        /**
         * Set the glyph loading flags. By default, fonts use the most
         * sensible flags when loading a font's glyph using FT_Load_Glyph().
         * This function allows to override the default flags.
         *
         * @param flags  The glyph loading flags.
         */
        virtual void GlyphLoadFlags(FT_Int flags);

        /**
         * Set the character map for the face.
         *
         * @param encoding      Freetype enumerate for char map code.
         * @return              <code>true</code> if charmap was valid and
         *                      set correctly.
         */
        virtual bool CharMap(FT_Encoding encoding);

        /**
         * Get the number of character maps in this face.
         *
         * @return character map count.
         */
        virtual unsigned int CharMapCount() const;

        /**
         * Get a list of character maps in this face.
         *
         * @return pointer to the first encoding.
         */
        virtual FT_Encoding* CharMapList();

        /**
         * Set the char size for the current face.
         *
         * @param size      the face size in points (1/72 inch)
         * @param res       the resolution of the target device.
         * @return          <code>true</code> if size was set correctly
         */
        virtual bool FaceSize(const unsigned int size,
                              const unsigned int res = 72);

        /**
         * Get the current face size in points (1/72 inch).
         *
         * @return face size
         */
        virtual unsigned int FaceSize() const;

        /**
         * Set the extrusion distance for the font. Only implemented by
         * FTExtrudeFont
         *
         * @param depth  The extrusion distance.
         */
        virtual void Depth(float depth);

        /**
         * Set the outset distance for the font. Only implemented by
         * FTOutlineFont, FTPolygonFont and FTExtrudeFont
         *
         * @param outset  The outset distance.
         */
        virtual void Outset(float outset);

        /**
         * Set the front and back outset distances for the font. Only
         * implemented by FTExtrudeFont
         *
         * @param front  The front outset distance.
         * @param back   The back outset distance.
         */
        virtual void Outset(float front, float back);

        /**
         * Enable or disable the use of Display Lists inside FTGL
         *
         * @param  useList <code>true</code> turns ON display lists.
         *                 <code>false</code> turns OFF display lists.
         */
        virtual void UseDisplayList(bool useList);

        /**
         * Get the global ascender height for the face.
         *
         * @return  Ascender height
         */
        virtual float Ascender() const;

        /**
         * Gets the global descender height for the face.
         *
         * @return  Descender height
         */
        virtual float Descender() const;

        /**
         * Gets the line spacing for the font.
         *
         * @return  Line height
         */
        virtual float LineHeight() const;

        /**
         * Get the bounding box for a string.
         *
         * @param string  A char buffer.
         * @param len  The length of the string. If < 0 then all characters
         *             will be checked until a null character is encountered
         *             (optional).
         * @param position  The pen position of the first character (optional).
         * @param spacing  A displacement vector to add after each character
         *                 has been checked (optional).
         * @return  The corresponding bounding box.
         */
        virtual FTBBox BBox(const char *string, const int len = -1,
                            FTPoint position = FTPoint(),
                            FTPoint spacing = FTPoint());

        /**
         * Get the bounding box for a string (deprecated).
         *
         * @param string  A char buffer.
         * @param llx  Lower left near x coordinate.
         * @param lly  Lower left near y coordinate.
         * @param llz  Lower left near z coordinate.
         * @param urx  Upper right far x coordinate.
         * @param ury  Upper right far y coordinate.
         * @param urz  Upper right far z coordinate.
         */
        void BBox(const char* string, float& llx, float& lly, float& llz,
                  float& urx, float& ury, float& urz)
        {
            FTBBox b = BBox(string);
            llx = b.Lower().Xf(); lly = b.Lower().Yf(); llz = b.Lower().Zf();
            urx = b.Upper().Xf(); ury = b.Upper().Yf(); urz = b.Upper().Zf();
        }

        /**
         * Get the bounding box for a string.
         *
         * @param string  A wchar_t buffer.
         * @param len  The length of the string. If < 0 then all characters
         *             will be checked until a null character is encountered
         *             (optional).
         * @param position  The pen position of the first character (optional).
         * @param spacing  A displacement vector to add after each character
         *                 has been checked (optional).
         * @return  The corresponding bounding box.
         */
        virtual FTBBox BBox(const wchar_t *string, const int len = -1,
                            FTPoint position = FTPoint(),
                            FTPoint spacing = FTPoint());

        /**
         * Get the bounding box for a string (deprecated).
         *
         * @param string  A wchar_t buffer.
         * @param llx  Lower left near x coordinate.
         * @param lly  Lower left near y coordinate.
         * @param llz  Lower left near z coordinate.
         * @param urx  Upper right far x coordinate.
         * @param ury  Upper right far y coordinate.
         * @param urz  Upper right far z coordinate.
         */
        void BBox(const wchar_t* string, float& llx, float& lly, float& llz,
                  float& urx, float& ury, float& urz)
        {
            FTBBox b = BBox(string);
            llx = b.Lower().Xf(); lly = b.Lower().Yf(); llz = b.Lower().Zf();
            urx = b.Upper().Xf(); ury = b.Upper().Yf(); urz = b.Upper().Zf();
        }

        /**
         * Get the advance for a string.
         *
         * @param string  'C' style string to be checked.
         * @param len  The length of the string. If < 0 then all characters
         *             will be checked until a null character is encountered
         *             (optional).
         * @param spacing  A displacement vector to add after each character
         *                 has been checked (optional).
         * @return  The string's advance width.
         */
        virtual float Advance(const char* string, const int len = -1,
                              FTPoint spacing = FTPoint());

        /**
         * Get the advance for a string.
         *
         * @param string  A wchar_t string
         * @param len  The length of the string. If < 0 then all characters
         *             will be checked until a null character is encountered
         *             (optional).
         * @param spacing  A displacement vector to add after each character
         *                 has been checked (optional).
         * @return  The string's advance width.
         */
        virtual float Advance(const wchar_t* string, const int len = -1,
                              FTPoint spacing = FTPoint());

        /**
         * Render a string of characters.
         *
         * @param string  'C' style string to be output.
         * @param len  The length of the string. If < 0 then all characters
         *             will be displayed until a null character is encountered
         *             (optional).
         * @param position  The pen position of the first character (optional).
         * @param spacing  A displacement vector to add after each character
         *                 has been displayed (optional).
         * @param renderMode  Render mode to use for display (optional).
         * @return  The new pen position after the last character was output.
         */
        virtual FTPoint Render(const char* string, const int len = -1,
                               FTPoint position = FTPoint(),
                               FTPoint spacing = FTPoint(),
                               int renderMode = FTGL::RENDER_ALL);

        /**
         * Render a string of characters
         *
         * @param string    wchar_t string to be output.
         * @param len  The length of the string. If < 0 then all characters
         *             will be displayed until a null character is encountered
         *             (optional).
         * @param position  The pen position of the first character (optional).
         * @param spacing  A displacement vector to add after each character
         *                 has been displayed (optional).
         * @param renderMode  Render mode to use for display (optional).
         * @return  The new pen position after the last character was output.
         */
        virtual FTPoint Render(const wchar_t *string, const int len = -1,
                               FTPoint position = FTPoint(),
                               FTPoint spacing = FTPoint(),
                               int renderMode = FTGL::RENDER_ALL);

        /**
         * Queries the Font for errors.
         *
         * @return  The current error code.
         */
        virtual FT_Error Error() const;

    protected:
        /* Allow impl to access MakeGlyph */
        friend class FTFontImpl;

        /**
         * Construct a glyph of the correct type.
         *
         * Clients must override the function and return their specialised
         * FTGlyph.
         *
         * @param slot  A FreeType glyph slot.
         * @return  An FT****Glyph or <code>null</code> on failure.
         */
        virtual FTGlyph* MakeGlyph(FT_GlyphSlot slot) = 0;

    private:
        /**
         * Internal FTGL FTFont implementation object. For private use only.
         */
        FTFontImpl *impl;
};

#endif //__cplusplus

FTGL_BEGIN_C_DECLS

/**
 * FTGLfont is the public interface for the FTGL library.
 *
 * It is good practice after using these functions to test the error
 * code returned. <code>FT_Error Error()</code>. Check the freetype file
 * fterrdef.h for error definitions.
 */
struct _FTGLFont;
typedef struct _FTGLfont FTGLfont;

/**
 * Create a custom FTGL font object.
 *
 * @param fontFilePath  The font file name.
 * @param data  A pointer to private data that will be passed to callbacks.
 * @param makeglyphCallback  A glyph-making callback function.
 * @return  An FTGLfont* object.
 */
FTGL_EXPORT FTGLfont *ftglCreateCustomFont(char const *fontFilePath,
                                           void *data,
                   FTGLglyph * (*makeglyphCallback) (FT_GlyphSlot, void *));

/**
 * Destroy an FTGL font object.
 *
 * @param font  An FTGLfont* object.
 */
FTGL_EXPORT void ftglDestroyFont(FTGLfont* font);

/**
 * Attach auxilliary file to font e.g. font metrics.
 *
 * Note: not all font formats implement this function.
 *
 * @param font  An FTGLfont* object.
 * @param path  Auxilliary font file path.
 * @return  1 if file has been attached successfully.
 */
FTGL_EXPORT int ftglAttachFile(FTGLfont* font, const char* path);

/**
 * Attach auxilliary data to font, e.g. font metrics, from memory.
 *
 * Note: not all font formats implement this function.
 *
 * @param font  An FTGLfont* object.
 * @param data  The in-memory buffer.
 * @param size  The length of the buffer in bytes.
 * @return  1 if file has been attached successfully.
 */
FTGL_EXPORT int ftglAttachData(FTGLfont* font, const unsigned char * data,
                               size_t size);

/**
 * Set the character map for the face.
 *
 * @param font  An FTGLfont* object.
 * @param encoding  Freetype enumerate for char map code.
 * @return  1 if charmap was valid and set correctly.
 */
FTGL_EXPORT int ftglSetFontCharMap(FTGLfont* font, FT_Encoding encoding);

/**
 * Get the number of character maps in this face.
 *
 * @param font  An FTGLfont* object.
 * @return character map count.
 */
FTGL_EXPORT unsigned int ftglGetFontCharMapCount(FTGLfont* font);

/**
 * Get a list of character maps in this face.
 *
 * @param font  An FTGLfont* object.
 * @return pointer to the first encoding.
 */
FTGL_EXPORT FT_Encoding* ftglGetFontCharMapList(FTGLfont* font);

/**
 * Set the char size for the current face.
 *
 * @param font  An FTGLfont* object.
 * @param size  The face size in points (1/72 inch).
 * @param res  The resolution of the target device, or 0 to use the default
 *             value of 72.
 * @return  1 if size was set correctly.
 */
FTGL_EXPORT int ftglSetFontFaceSize(FTGLfont* font, unsigned int size,
                                    unsigned int res);

/**
 * Get the current face size in points (1/72 inch).
 *
 * @param font  An FTGLfont* object.
 * @return face size
 */
FTGL_EXPORT unsigned int ftglGetFontFaceSize(FTGLfont* font);

/**
 * Set the extrusion distance for the font. Only implemented by
 * FTExtrudeFont.
 *
 * @param font  An FTGLfont* object.
 * @param depth  The extrusion distance.
 */
FTGL_EXPORT void ftglSetFontDepth(FTGLfont* font, float depth);

/**
 * Set the outset distance for the font. Only FTOutlineFont, FTPolygonFont
 * and FTExtrudeFont implement front outset. Only FTExtrudeFont implements
 * back outset.
 *
 * @param font  An FTGLfont* object.
 * @param front  The front outset distance.
 * @param back  The back outset distance.
 */
FTGL_EXPORT void ftglSetFontOutset(FTGLfont* font, float front, float back);

/**
 * Enable or disable the use of Display Lists inside FTGL.
 *
 * @param font  An FTGLfont* object.
 * @param useList  1 turns ON display lists.
 *                 0 turns OFF display lists.
 */
FTGL_EXPORT void ftglSetFontDisplayList(FTGLfont* font, int useList);

/**
 * Get the global ascender height for the face.
 *
 * @param font  An FTGLfont* object.
 * @return  Ascender height
 */
FTGL_EXPORT float ftglGetFontAscender(FTGLfont* font);

/**
 * Gets the global descender height for the face.
 *
 * @param font  An FTGLfont* object.
 * @return  Descender height
 */
FTGL_EXPORT float ftglGetFontDescender(FTGLfont* font);

/**
 * Gets the line spacing for the font.
 *
 * @param font  An FTGLfont* object.
 * @return  Line height
 */
FTGL_EXPORT float ftglGetFontLineHeight(FTGLfont* font);

/**
 * Get the bounding box for a string.
 *
 * @param font  An FTGLfont* object.
 * @param string  A char buffer
 * @param len  The length of the string. If < 0 then all characters will be
 *             checked until a null character is encountered (optional).
 * @param bounds  An array of 6 float values where the bounding box's lower
 *                left near and upper right far 3D coordinates will be stored.
 */
FTGL_EXPORT void ftglGetFontBBox(FTGLfont* font, const char *string,
                                 int len, float bounds[6]);

/**
 * Get the advance width for a string.
 *
 * @param font  An FTGLfont* object.
 * @param string  A char string.
 * @return  Advance width
 */
FTGL_EXPORT float ftglGetFontAdvance(FTGLfont* font, const char *string);

/**
 * Render a string of characters.
 *
 * @param font  An FTGLfont* object.
 * @param string  Char string to be output.
 * @param mode  Render mode to display.
 */
FTGL_EXPORT void ftglRenderFont(FTGLfont* font, const char *string, int mode);

/**
 * Query a font for errors.
 *
 * @param font  An FTGLfont* object.
 * @return  The current error code.
 */
FTGL_EXPORT FT_Error ftglGetFontError(FTGLfont* font);

FTGL_END_C_DECLS

#endif  //  __FTFont__