/***************************************************************************/ /* */ /* ftglyph.h */ /* */ /* FreeType convenience functions to handle glyphs (specification). */ /* */ /* Copyright 1996-2000 by */ /* David Turner, Robert Wilhelm, and Werner Lemberg. */ /* */ /* This file is part of the FreeType project, and may only be used, */ /* modified, and distributed under the terms of the FreeType project */ /* license, LICENSE.TXT. By continuing to use, modify, or distribute */ /* this file you indicate that you have read the license and */ /* understand and accept it fully. */ /* */ /***************************************************************************/ /*************************************************************************/ /* */ /* This file contains the definition of several convenience functions */ /* that can be used by client applications to easily retrieve glyph */ /* bitmaps and outlines from a given face. */ /* */ /* These functions should be optional if you are writing a font server */ /* or text layout engine on top of FreeType. However, they are pretty */ /* handy for many other simple uses of the library. */ /* */ /*************************************************************************/ #ifndef FTGLYPH_H #define FTGLYPH_H #include #ifdef __cplusplus extern "C" { #endif /* forward declaration to a private type */ typedef struct FT_Glyph_Class_ FT_Glyph_Class; /*************************************************************************/ /* */ /* */ /* FT_GlyphRec */ /* */ /* */ /* The root glyph structure contains a given glyph image plus its */ /* advance width in 16.16 fixed float format. */ /* */ /* */ /* library :: A handle to the FreeType library object. */ /* */ /* clazz :: A pointer to the glyph's class. Private. */ /* */ /* format :: The format of the glyph's image. */ /* */ /* advance :: A 16.16 vector that gives the glyph's advance width. */ /* */ typedef struct FT_GlyphRec_ { FT_Library library; const FT_Glyph_Class* clazz; FT_Glyph_Format format; FT_Vector advance; } FT_GlyphRec, *FT_Glyph; /*************************************************************************/ /* */ /* */ /* FT_BitmapGlyphRec */ /* */ /* */ /* A structure used for bitmap glyph images. This really is a */ /* `sub-class' of `FT_GlyphRec'. */ /* */ /* */ /* root :: The root FT_Glyph fields. */ /* */ /* left :: The left-side bearing, i.e., the horizontal distance */ /* from the current pen position to the left border of the */ /* glyph bitmap. */ /* */ /* top :: The top-side bearing, i.e., the vertical distance from */ /* the current pen position to the top border of the glyph */ /* bitmap. This distance is positive for upwards-y! */ /* */ /* bitmap :: A descriptor for the bitmap. */ /* */ /* */ /* You can typecast FT_Glyph to FT_BitmapGlyph if you have */ /* glyph->format == ft_glyph_format_bitmap. This lets you access */ /* the bitmap's contents easily. */ /* */ /* The corresponding pixel buffer is always owned by the BitmapGlyph */ /* and is thus created and destroyed with it. */ /* */ typedef struct FT_BitmapGlyphRec_ { FT_GlyphRec root; FT_Int left; FT_Int top; FT_Bitmap bitmap; } FT_BitmapGlyphRec, *FT_BitmapGlyph; /*************************************************************************/ /* */ /* */ /* FT_OutlineGlyphRec */ /* */ /* */ /* A structure used for outline (vectorial) glyph images. This */ /* really is a `sub-class' of `FT_GlyphRec'. */ /* */ /* */ /* root :: The root FT_Glyph fields. */ /* */ /* outline :: A descriptor for the outline. */ /* */ /* */ /* You can typecast FT_Glyph to FT_OutlineGlyph if you have */ /* glyph->format == ft_glyph_format_outline. This lets you access */ /* the outline's content easily. */ /* */ /* As the outline is extracted from a glyph slot, its coordinates are */ /* expressed normally in 26.6 pixels, unless the flag */ /* FT_LOAD_NO_SCALE was used in FT_Load_Glyph() or FT_Load_Char(). */ /* */ /* The outline's tables are always owned by the object and are */ /* destroyed with it. */ /* */ typedef struct FT_OutlineGlyphRec_ { FT_GlyphRec root; FT_Outline outline; } FT_OutlineGlyphRec, *FT_OutlineGlyph; /*************************************************************************/ /* */ /* */ /* FT_Get_Glyph */ /* */ /* */ /* A function used to extract a glyph image from a slot. */ /* */ /* */ /* slot :: A handle to the source glyph slot. */ /* */ /* */ /* aglyph :: A handle to the glyph object. */ /* */ /* */ /* FreeType error code. 0 means success. */ /* */ FT_EXPORT_DEF( FT_Error ) FT_Get_Glyph( FT_GlyphSlot slot, FT_Glyph* aglyph ); /*************************************************************************/ /* */ /* */ /* FT_Glyph_Copy */ /* */ /* */ /* A function used to copy a glyph image. */ /* */ /* */ /* source :: A handle to the source glyph object. */ /* */ /* */ /* target :: A handle to the target glyph object. 0 in case of */ /* error. */ /* */ /* */ /* FreeType error code. 0 means success. */ /* */ FT_EXPORT_DEF( FT_Error ) FT_Glyph_Copy( FT_Glyph source, FT_Glyph* target ); /*************************************************************************/ /* */ /* */ /* FT_Glyph_Transform */ /* */ /* */ /* Transforms a glyph image if its format is scalable. */ /* */ /* */ /* glyph :: A handle to the target glyph object. */ /* */ /* matrix :: A pointer to a 2x2 matrix to apply. */ /* */ /* delta :: A pointer to a 2d vector to apply. Coordinates are */ /* expressed in 1/64th of a pixel. */ /* */ /* */ /* FreeType error code (the glyph format is not scalable if it is */ /* not zero). */ /* */ /* */ /* The 2x2 transformation matrix is also applied to the glyph's */ /* advance vector. */ /* */ FT_EXPORT_DEF( FT_Error ) FT_Glyph_Transform( FT_Glyph glyph, FT_Matrix* matrix, FT_Vector* delta ); enum { ft_glyph_bbox_pixels = 0, ft_glyph_bbox_subpixels = 1, ft_glyph_bbox_gridfit = 2 }; /*************************************************************************/ /* */ /* */ /* FT_Glyph_Get_CBox */ /* */ /* */ /* Returns the glyph image's bounding box. */ /* */ /* */ /* glyph :: A handle to the source glyph object. */ /* */ /* mode :: A set of bit flags that indicate how to interpret the */ /* returned bounding box values. */ /* */ /* */ /* box :: The glyph bounding box. Coordinates are expressed in */ /* 1/64th of pixels if it is grid-fitted. */ /* */ /* */ /* Coordinates are relative to the glyph origin, using the Y-upwards */ /* convention. */ /* */ /* If `ft_glyph_bbox_subpixels' is set in `mode', the bbox */ /* coordinates are returned in 26.6 pixels (i.e. 1/64th of pixels). */ /* Otherwise, coordinates are expressed in integer pixels. */ /* */ /* Note that the maximum coordinates are exclusive, which means that */ /* one can compute the width and height of the glyph image (be it in */ /* integer or 26.6 pixels) as: */ /* */ /* width = bbox.xMax - bbox.xMin; */ /* height = bbox.yMax - bbox.yMin; */ /* */ /* Note also that for 26.6 coordinates, if the */ /* `ft_glyph_bbox_gridfit' flag is set in `mode;, the coordinates */ /* will also be grid-fitted, which corresponds to: */ /* */ /* bbox.xMin = FLOOR(bbox.xMin); */ /* bbox.yMin = FLOOR(bbox.yMin); */ /* bbox.xMax = CEILING(bbox.xMax); */ /* bbox.yMax = CEILING(bbox.yMax); */ /* */ /* The default value (0) for `bbox_mode' is `ft_glyph_bbox_pixels'. */ /* */ FT_EXPORT_DEF( void ) FT_Glyph_Get_CBox( FT_Glyph glyph, FT_UInt bbox_mode, FT_BBox* cbox ); /*************************************************************************/ /* */ /* */ /* FT_Glyph_To_Bitmap */ /* */ /* */ /* Converts a given glyph object to a bitmap glyph object. */ /* */ /* */ /* glyph :: A pointer to a handle to the target glyph. */ /* */ /* */ /* render_mode :: A set of bit flags that describe how the data is */ /* */ /* */ /* origin :: A pointer to a vector used to translate the glyph */ /* image before rendering. Can be 0 (if no */ /* translation). The origin is expressed in */ /* 26.6 pixels. */ /* */ /* destroy :: A boolean that indicates that the original glyph */ /* image should be destroyed by this function. It is */ /* never destroyed in case of error. */ /* */ /* */ /* FreeType error code. 0 means success. */ /* */ /* */ /* The glyph image is translated with the `origin' vector before */ /* rendering. In case of error, it it translated back to its */ /* original position and the glyph is left untouched. */ /* */ /* The first parameter is a pointer to a FT_Glyph handle, that will */ /* be replaced by this function. Typically, you would use (omitting */ /* error handling): */ /* */ /* */ /* { */ /* FT_Glyph glyph; */ /* FT_BitmapGlyph glyph_bitmap; */ /* */ /* */ /* // load glyph */ /* error = FT_Load_Char( face, glyph_index, FT_LOAD_DEFAUT ); */ /* */ /* // extract glyph image */ /* error = FT_Get_Glyph( face->glyph, &glyph ); */ /* */ /* // convert to a bitmap (default render mode + destroy old) */ /* if ( glyph->format != ft_glyph_format_bitmap ) */ /* { */ /* error = FT_Glyph_To_Bitmap( &glyph, ft_render_mode_default, */ /* 0, 1 ); */ /* if ( error ) // glyph unchanged */ /* ... */ /* } */ /* */ /* // access bitmap content by typecasting */ /* glyph_bitmap = (FT_BitmapGlyph)glyph; */ /* */ /* // do funny stuff with it, like blitting/drawing */ /* ... */ /* */ /* // discard glyph image (bitmap or not) */ /* FT_Done_Glyph( glyph ); */ /* } */ /* */ /* */ /* This function will always fail if the glyph's format isn't */ /* scalable. */ /* */ FT_EXPORT_DEF( FT_Error ) FT_Glyph_To_Bitmap( FT_Glyph* the_glyph, FT_ULong render_mode, FT_Vector* origin, FT_Bool destroy ); /*************************************************************************/ /* */ /* */ /* FT_Done_Glyph */ /* */ /* */ /* Destroys a given glyph. */ /* */ /* */ /* glyph :: A handle to the target glyph object. */ /* */ FT_EXPORT_DEF( void ) FT_Done_Glyph( FT_Glyph glyph ); /* other helpful functions */ /*************************************************************************/ /* */ /* */ /* FT_Matrix_Multiply */ /* */ /* */ /* Performs the matrix operation `b = a*b'. */ /* */ /* */ /* a :: A pointer to matrix `a'. */ /* */ /* */ /* b :: A pointer to matrix `b'. */ /* */ /* */ /* Yes. */ /* */ /* */ /* The result is undefined if either `a' or `b' is zero. */ /* */ FT_EXPORT_DEF( void ) FT_Matrix_Multiply( FT_Matrix* a, FT_Matrix* b ); /*************************************************************************/ /* */ /* */ /* FT_Matrix_Invert */ /* */ /* */ /* Inverts a 2x2 matrix. Returns an error if it can't be inverted. */ /* */ /* */ /* matrix :: A pointer to the target matrix. Remains untouched in */ /* case of error. */ /* */ /* */ /* FreeType error code. 0 means success. */ /* */ /* */ /* Yes. */ /* */ FT_EXPORT_DEF( FT_Error ) FT_Matrix_Invert( FT_Matrix* matrix ); #ifdef __cplusplus } #endif #endif /* FTGLYPH_H */ /* END */