freetype2/src/type1z/t1gload.h
David Turner 2dfb5aca28 added a new experimental Type 1 driver. This version sports several
improvements compared to "src/type1". Briefly :

  - the postscript-like interpreter is now gone. We now perform
    pattern-matching to load our font content. The resultant code
    is much faster, smaller, and easier to maintain.

    For a more detailed description, see the comments at the start
    of "src/type1z/t1objs.c"

  - the glyph loader will be greatly simplified really soon, and the
    clumsy hinter will be ditched in favor of a more general auto-hinting
    module (when we get one).

    The goal is to strip down the Type1 driver to about 15-20 Kb.

This is still an experimental version. It is added to the repository
for archiving. You should not try to use it for now (it won't work
because some crucial parts are _knowingly_ ignored for now !).

Note that the "old" type1 driver will probably move to the "demos/src"
directory, in order to show how one can replace one given font driver
at runtime (and to provide the functionality of the "t1dump" program).
2000-01-27 14:02:04 +00:00

437 lines
17 KiB
C

/*******************************************************************
*
* t1gload.h 1.0
*
* Type1 Glyph Loader.
*
* Copyright 1996-1998 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 Type 1 glyph loader uses three distinct objects to build
* scaled and hinted outlines from a charstrings program. These are :
*
* - a glyph builder, T1_Builder, used to store the built outline
*
* - a glyph hinter, T1_Hinter, used to record and apply the stem
* hints
*
* - a charstrings interpreter, T1_Decoder, used to parse the
* Type 1 charstrings stream, manage a stack and call the builder
* and/or hinter depending on the opcodes.
*
* Ideally, a Type 2 glyph loader would only need to have its own
* T2_Decoder object (assuming the hinter is able to manage all
* kinds of hints).
*
******************************************************************/
#ifndef T1GLOAD_H
#define T1GLOAD_H
#include <t1objs.h>
#ifdef __cplusplus
extern "C" {
#endif
/*************************************************************************/
/* */
/* <Structure> T1_Builder_Funcs */
/* */
/* <Description> */
/* a structure used to store the address of various functions */
/* used by a glyph builder to implement the outline's "path */
/* construction". */
/* */
/* */
typedef struct T1_Builder_ T1_Builder;
typedef T1_Error (*T1_Builder_EndChar)( T1_Builder* loader );
typedef T1_Error (*T1_Builder_Sbw) ( T1_Builder* loader,
T1_Pos sbx,
T1_Pos sby,
T1_Pos wx,
T1_Pos wy );
typedef T1_Error (*T1_Builder_ClosePath)( T1_Builder* loader );
typedef T1_Error (*T1_Builder_RLineTo)( T1_Builder* loader,
T1_Pos dx,
T1_Pos dy );
typedef T1_Error (*T1_Builder_RMoveTo)( T1_Builder* loader,
T1_Pos dx,
T1_Pos dy );
typedef T1_Error (*T1_Builder_RCurveTo)( T1_Builder* loader,
T1_Pos dx1,
T1_Pos dy1,
T1_Pos dx2,
T1_Pos dy2,
T1_Pos dx3,
T1_Pos dy3 );
typedef struct T1_Builder_Funcs_
{
T1_Builder_EndChar end_char;
T1_Builder_Sbw set_bearing_point;
T1_Builder_ClosePath close_path;
T1_Builder_RLineTo rline_to;
T1_Builder_RMoveTo rmove_to;
T1_Builder_RCurveTo rcurve_to;
} T1_Builder_Funcs;
/*************************************************************************/
/* */
/* <Structure> T1_Builder */
/* */
/* <Description> */
/* a structure used during glyph loading to store its outline. */
/* */
/* <Fields> */
/* system :: current system object */
/* face :: current face object */
/* size :: current size object */
/* glyph :: current glyph slot */
/* */
/* current :: current glyph outline */
/* base :: base glyph outline */
/* */
/* max_points :: maximum points in builder outline */
/* max_contours :: maximum contours in builder outline */
/* */
/* last :: last point position */
/* */
/* scale_x :: horizontal scale ( FUnits to sub-pixels ) */
/* scale_y :: vertical scale ( FUnits to sub-pixels ) */
/* pos_x :: horizontal translation (composite glyphs) */
/* pos_y :: vertical translation (composite glyph) */
/* */
/* left_bearing :: left side bearing point */
/* advance :: horizontal advance vector */
/* */
/* path_begun :: flag, indicates that a new path has begun */
/* load_points :: flag, if not set, no points are loaded */
/* */
/* pass :: pass number for multi-pass hinters */
/* */
/* funcs :: table of builder functions used to perform */
/* the outline's path construction */
/* */
/* hint_point :: index of next point to hint.. */
/* */
/* */
/* */
/* */
struct T1_Builder_
{
FT_Memory memory;
T1_Face face;
T1_Size size;
T1_GlyphSlot glyph;
FT_Outline current; /* the current glyph outline */
FT_Outline base; /* the composite glyph outline */
T1_Int max_points; /* capacity of base outline in points */
T1_Int max_contours; /* capacity of base outline in contours */
T1_Vector last;
T1_Fixed scale_x;
T1_Fixed scale_y;
T1_Pos pos_x;
T1_Pos pos_y;
T1_Vector left_bearing;
T1_Vector advance;
T1_BBox bbox; /* bounding box */
T1_Bool path_begun;
T1_Bool load_points;
T1_Int pass;
T1_Int hint_point;
/* path construction function interface */
T1_Builder_Funcs funcs;
};
/*************************************************************************/
/* */
/* <Structure> T1_Hinter_Funcs */
/* */
/* <Description> */
/* a structure used to store the address of various functions */
/* used by a Type 1 hinter to perform outline hinting. */
/* */
typedef T1_Error (*T1_Hinter_ChangeHints)( T1_Builder* builder );
typedef T1_Error (*T1_Hinter_DotSection)( T1_Builder* builder );
typedef T1_Error (*T1_Hinter_Stem)( T1_Builder* builder,
T1_Pos pos,
T1_Pos width,
T1_Bool vertical );
typedef T1_Error (*T1_Hinter_Stem3)( T1_Builder* builder,
T1_Pos pos0,
T1_Pos width0,
T1_Pos pos1,
T1_Pos width1,
T1_Pos pos2,
T1_Pos width2,
T1_Bool vertical );
typedef struct T1_Hinter_Func_
{
T1_Hinter_ChangeHints change_hints;
T1_Hinter_DotSection dot_section;
T1_Hinter_Stem stem;
T1_Hinter_Stem3 stem3;
} T1_Hinter_Funcs;
typedef enum T1_Operator_
{
op_none = 0,
op_endchar,
op_hsbw,
op_seac,
op_sbw,
op_closepath,
op_hlineto,
op_hmoveto,
op_hvcurveto,
op_rlineto,
op_rmoveto,
op_rrcurveto,
op_vhcurveto,
op_vlineto,
op_vmoveto,
op_dotsection,
op_hstem,
op_hstem3,
op_vstem,
op_vstem3,
op_div,
op_callothersubr,
op_callsubr,
op_pop,
op_return,
op_setcurrentpoint,
op_max /* never remove this one */
} T1_Operator;
/* execution context charstring zone */
typedef struct T1_Decoder_Zone_
{
T1_Byte* base;
T1_Byte* limit;
T1_Byte* cursor;
} T1_Decoder_Zone;
typedef struct T1_Decoder_
{
T1_Builder builder;
T1_Hinter_Funcs hinter;
T1_Int stack[ T1_MAX_CHARSTRINGS_OPERANDS ];
T1_Int* top;
T1_Decoder_Zone zones[ T1_MAX_SUBRS_CALLS+1 ];
T1_Decoder_Zone* zone;
T1_Int flex_state;
T1_Int num_flex_vectors;
T1_Vector flex_vectors[7];
} T1_Decoder;
/*********************************************************************
*
* <Function>
* T1_Init_Builder
*
* <Description>
* Initialise a given glyph builder.
*
* <Input>
* builder :: glyph builder to initialise
* face :: current face object
* size :: current size object
* glyph :: current glyph object
* funcs :: glyph builder functions (or "methods").
*
* <Note>
* This function is exported for now because it is used by the
* "t1dump" utility. Later, it will be accessed through a
* format-specific extension
*
*********************************************************************/
EXPORT_DEF
void T1_Init_Builder( T1_Builder* builder,
T1_Face face,
T1_Size size,
T1_GlyphSlot glyph,
const T1_Builder_Funcs* funcs );
/*********************************************************************
*
* <Function>
* T1_Done_Builder
*
* <Description>
* Finalise a given glyph builder. Its content can still be
* used after the call, but the function saves important information
* within the corresponding glyph slot.
*
* <Input>
* builder :: glyph builder to initialise
*
* <Note>
* This function is exported for now because it is used by the
* "t1dump" utility. Later, it will be accessed through a
* format-specific extension
*
*********************************************************************/
EXPORT_DEF
void T1_Done_Builder( T1_Builder* builder );
/*********************************************************************
*
* <Function>
* T1_Init_Decoder
*
* <Description>
* Initialise a given Type 1 decoder for parsing
*
* <Input>
* decoder :: Type 1 decoder to initialise
* funcs :: hinter functions interface
*
* <Note>
* This function is exported for now because it is used by the
* "t1dump" utility. Later, it will be accessed through a
* format-specific extension
*
*********************************************************************/
EXPORT_DEF
void T1_Init_Decoder( T1_Decoder* decoder,
const T1_Hinter_Funcs* funcs );
/* Compute the maximum advance width of a font through quick parsing */
LOCAL_DEF
T1_Error T1_Compute_Max_Advance( T1_Face face,
T1_Int *max_advance );
/* This function is exported, because it is used by the T1Dump utility */
EXPORT_DEF
T1_Error T1_Parse_CharStrings( T1_Decoder* decoder,
T1_Byte* charstring_base,
T1_Int charstring_len,
T1_Int num_subrs,
T1_Byte** subrs_base,
T1_Int* subrs_len );
/*************************************************************************/
/* */
/* <Function> T1_Add_Points */
/* */
/* <Description> */
/* Checks that there is enough room in the current load glyph outline */
/* to accept "num_points" additional outline points. If not, this */
/* function grows the load outline's arrays accordingly.. */
/* */
/* <Input> */
/* builder :: pointer to glyph builder object */
/* num_points :: number of points that will be added later */
/* */
/* <Return> */
/* Type1 error code. 0 means success */
/* */
/* <Note> */
/* This function does NOT update the points count in the glyph loader */
/* This must be done by the caller itself, after this function is */
/* invoked.. */
/* */
LOCAL_DEF
T1_Error T1_Add_Points( T1_Builder* builder,
T1_Int num_points );
/*************************************************************************/
/* */
/* <Function> T1_Add_Contours */
/* */
/* <Description> */
/* Checks that there is enough room in the current load glyph outline */
/* to accept "num_contours" additional contours. If not, this func */
/* the load outline's arrays accordingly.. */
/* */
/* <Input> */
/* builder :: pointer to glyph builder object */
/* num_contours :: number of contours that will be added later */
/* */
/* <Return> */
/* Type1 error code. 0 means success */
/* */
/* <Note> */
/* This function does NOT update the contours count in the load glyph */
/* This must be done by the caller itself, after this function is */
/* invoked.. */
/* */
LOCAL_DEF
T1_Error T1_Add_Contours( T1_Builder* builder,
T1_Int num_contours );
LOCAL_DEF
T1_Error T1_Load_Glyph( T1_GlyphSlot glyph,
T1_Size size,
T1_Int glyph_index,
T1_Int load_flags );
#ifdef __cplusplus
}
#endif
#endif /* T1GLOAD_H */