ref: de6523ee05779c4cf3545bf49e297489a57d6142
dir: /src/type1/t1hinter.h/
/******************************************************************* * * t1hinter.h 1.2 * * Type1 hinter. * * Copyright 1996-1999 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. * * * The Hinter is in charge of fitting th scaled outline to the * pixel grid in order to considerably improve the quality of * the Type 1 font driver's output.. * ******************************************************************/ #ifndef T1HINTER_H #define T1HINTER_H #include <t1objs.h> #include <t1gload.h> #ifdef __cplusplus extern "C" { #endif /************************************************************************ * * <Struct> * T1_Snap_Zone * * <Description> * A "snap zone" is used to model either a blue zone or a stem width * at a given character size. It is made of a minimum and maximum * edge, defined in 26.6 pixels, as well as one "original" and * "scaled" position. * * the position corresponds to the stem width (for stem snap zones) * or to the blue position (for blue zones) * * <Fields> * orus :: original position in font units * pix :: current position in sub-pixel units * min :: minimum boundary in sub-pixel units * max :: maximim boundary in sub-pixel units * ************************************************************************/ typedef struct T1_Snap_Zone_ { T1_Pos orus; T1_Pos pix; T1_Pos min; T1_Pos max; } T1_Snap_Zone; /************************************************************************ * * <Struct> * T1_Edge * * <Description> * A very simply structure used to model an stem edge * * <Fields> * orus :: original edge position in font units * pix :: scaled edge position in sub-pixel units * ************************************************************************/ typedef struct T1_Edge_ { T1_Pos orus; T1_Pos pix; } T1_Edge; /************************************************************************ * * <Struct> * T1_Stem_Hint * * <Description> * A simple structure used to model a stem hint * * <Fields> * min_edge :: the hint's minimum edge * max_edge :: the hint's maximum edge * hint_flags :: some flags describing the stem properties * * <Note> * the min and max edges of a ghost stem have the same position, * even if they're coded in a weird way in the charstrings * ************************************************************************/ typedef struct T1_Stem_Hint_ { T1_Edge min_edge; T1_Edge max_edge; T1_Int hint_flags; } T1_Stem_Hint; #define T1_HINT_FLAG_ACTIVE 1 /* indicates an active stem */ #define T1_HINT_FLAG_MIN_BORDER 2 /* unused for now.. */ #define T1_HINT_FLAG_MAX_BORDER 4 /* unused for now.. */ /* hinter's configuration constants */ #define T1_HINTER_MAX_BLUES 24 /* maximum number of blue zones */ #define T1_HINTER_MAX_SNAPS 16 /* maximum number of stem snap zones */ #define T1_HINTER_MAX_EDGES 64 /* maximum number of stem hints */ /************************************************************************ * * <Struct> * T1_Size_Hints * * <Description> * A structure used to model the hinting information related to * a size object * * <Fields> * supress_overshoots :: a boolean flag to tell when overshoot * supression should occur. * * num_blue_zones :: the total number of blue zones (top+bottom) * num_bottom_zones :: the number of bottom zones * * blue_zones :: the blue zones table. bottom zones are * stored first in the table, followed by * all top zones * * num_stem_snapH :: number of horizontal stem snap zones * stem_snapH :: horizontal stem snap zones * * num_stem_snapV :: number of vertical stem snap zones * stem_snapV :: vertical stem snap zones * ************************************************************************/ struct T1_Size_Hints_ { T1_Bool supress_overshoots; T1_Int num_blue_zones; T1_Int num_bottom_zones; T1_Snap_Zone blue_zones[ T1_HINTER_MAX_BLUES ]; T1_Int num_snap_widths; T1_Snap_Zone snap_widths[ T1_HINTER_MAX_SNAPS ]; T1_Int num_snap_heights; T1_Snap_Zone snap_heights[ T1_HINTER_MAX_SNAPS ]; }; /************************************************************************ * * <Struct> * T1_Stem_Table * * <Description> * A simple structure used to model a set of stem hints in a * single direction during the loading of a given glyph outline. * Not all stem hints are active at a time. Moreover, stems must * be sorted regularly * * <Fields> * num_stems :: total number of stems in table * num_active :: number of active stems in table * * stems :: the table of all stems * sort :: a table of indices into the stems table, used * to keep a sorted list of the active stems * ************************************************************************/ typedef struct T1_Stem_Table_ { T1_Int num_stems; T1_Int num_active; T1_Stem_Hint stems[ T1_HINTER_MAX_EDGES ]; T1_Int sort [ T1_HINTER_MAX_EDGES ]; } T1_Stem_Table; /************************************************************************ * * <Struct> * T1_Glyph_Hints * * <Description> * A structure used to model the stem hints of a given glyph outline * during glyph loading. * * <Fields> * hori_stems :: horizontal stem hints table * vert_stems :: vertical stem hints table * ************************************************************************/ struct T1_Glyph_Hints_ { T1_Stem_Table hori_stems; T1_Stem_Table vert_stems; }; /************************************************************************ * * <Data> * t1_hinter_funcs * * <Description> * A table containing the address of various functions used during * the loading of an hinted scaled outline * ************************************************************************/ LOCAL_DEF const T1_Hinter_Funcs t1_hinter_funcs; /************************************************************************ * * <Function> * T1_New_Size_Hinter * * <Description> * Allocates a new hinter structure for a given size object * * <Input> * size :: handle to target size object * * <Return> * Error code. 0 means success * ************************************************************************/ LOCAL_DEF T1_Error T1_New_Size_Hinter( T1_Size size ); /************************************************************************ * * <Function> * T1_Done_Size_Hinter * * <Description> * Releases a given size object's hinter structure * * <Input> * size :: handle to target size object * ************************************************************************/ LOCAL_DEF void T1_Done_Size_Hinter( T1_Size size ); /************************************************************************ * * <Function> * T1_Reset_Size_Hinter * * <Description> * Recomputes hinting information when a given size object has * changed its resolutions/char sizes/pixel sizes * * <Input> * size :: handle to size object * * <Return> * Error code. 0 means success * ************************************************************************/ LOCAL_DEF T1_Error T1_Reset_Size_Hinter( T1_Size size ); /************************************************************************ * * <Function> * T1_New_Glyph_Hinter * * <Description> * Allocates a new hinter structure for a given glyph slot * * <Input> * glyph :: handle to target glyph slot * * <Return> * Error code. 0 means success * ************************************************************************/ LOCAL_DEF T1_Error T1_New_Glyph_Hinter( T1_GlyphSlot glyph ); /************************************************************************ * * <Function> * T1_Done_Glyph_Hinter * * <Description> * Releases a given glyph slot's hinter structure * * <Input> * glyph :: handle to glyph slot * ************************************************************************/ LOCAL_DEF void T1_Done_Glyph_Hinter( T1_GlyphSlot glyph ); /************************************************************************ * * <Function> * T1_Hint_Points * * <Description> * this function grid-fits several points in a given Type 1 builder * at once. * * <Input> * builder :: handle to target Type 1 builder * ************************************************************************/ LOCAL_DEF void T1_Hint_Points( T1_Builder* builder ); /************************************************************************ * * <Function> * T1_Hint_Stems * * <Description> * This function is used to compute the location of each stem hint * between the first and second passes of the glyph loader on the * charstring. * * <Input> * builder :: handle to target builder * ************************************************************************/ LOCAL_DEF void T1_Hint_Stems( T1_Builder* builder ); #ifdef __cplusplus } #endif #endif /* T1HINTER_H */