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Diffstat (limited to 'modules/freetype2/include/freetype/internal/pshints.h')
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1 files changed, 699 insertions, 0 deletions
diff --git a/modules/freetype2/include/freetype/internal/pshints.h b/modules/freetype2/include/freetype/internal/pshints.h new file mode 100644 index 0000000000..ededc4c72e --- /dev/null +++ b/modules/freetype2/include/freetype/internal/pshints.h @@ -0,0 +1,699 @@ +/**************************************************************************** + * + * pshints.h + * + * Interface to Postscript-specific (Type 1 and Type 2) hints + * recorders (specification only). These are used to support native + * T1/T2 hints in the 'type1', 'cid', and 'cff' font drivers. + * + * Copyright (C) 2001-2023 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. + * + */ + + +#ifndef PSHINTS_H_ +#define PSHINTS_H_ + + +#include <freetype/freetype.h> +#include <freetype/t1tables.h> + + +FT_BEGIN_HEADER + + + /*************************************************************************/ + /*************************************************************************/ + /***** *****/ + /***** INTERNAL REPRESENTATION OF GLOBALS *****/ + /***** *****/ + /*************************************************************************/ + /*************************************************************************/ + + typedef struct PSH_GlobalsRec_* PSH_Globals; + + typedef FT_Error + (*PSH_Globals_NewFunc)( FT_Memory memory, + T1_Private* private_dict, + PSH_Globals* aglobals ); + + typedef void + (*PSH_Globals_SetScaleFunc)( PSH_Globals globals, + FT_Fixed x_scale, + FT_Fixed y_scale, + FT_Fixed x_delta, + FT_Fixed y_delta ); + + typedef void + (*PSH_Globals_DestroyFunc)( PSH_Globals globals ); + + + typedef struct PSH_Globals_FuncsRec_ + { + PSH_Globals_NewFunc create; + PSH_Globals_SetScaleFunc set_scale; + PSH_Globals_DestroyFunc destroy; + + } PSH_Globals_FuncsRec, *PSH_Globals_Funcs; + + + /*************************************************************************/ + /*************************************************************************/ + /***** *****/ + /***** PUBLIC TYPE 1 HINTS RECORDER *****/ + /***** *****/ + /*************************************************************************/ + /*************************************************************************/ + + /************************************************************************** + * + * @type: + * T1_Hints + * + * @description: + * This is a handle to an opaque structure used to record glyph hints + * from a Type 1 character glyph character string. + * + * The methods used to operate on this object are defined by the + * @T1_Hints_FuncsRec structure. Recording glyph hints is normally + * achieved through the following scheme: + * + * - Open a new hint recording session by calling the 'open' method. + * This rewinds the recorder and prepare it for new input. + * + * - For each hint found in the glyph charstring, call the corresponding + * method ('stem', 'stem3', or 'reset'). Note that these functions do + * not return an error code. + * + * - Close the recording session by calling the 'close' method. It + * returns an error code if the hints were invalid or something strange + * happened (e.g., memory shortage). + * + * The hints accumulated in the object can later be used by the + * PostScript hinter. + * + */ + typedef struct T1_HintsRec_* T1_Hints; + + + /************************************************************************** + * + * @type: + * T1_Hints_Funcs + * + * @description: + * A pointer to the @T1_Hints_FuncsRec structure that defines the API of + * a given @T1_Hints object. + * + */ + typedef const struct T1_Hints_FuncsRec_* T1_Hints_Funcs; + + + /************************************************************************** + * + * @functype: + * T1_Hints_OpenFunc + * + * @description: + * A method of the @T1_Hints class used to prepare it for a new Type 1 + * hints recording session. + * + * @input: + * hints :: + * A handle to the Type 1 hints recorder. + * + * @note: + * You should always call the @T1_Hints_CloseFunc method in order to + * close an opened recording session. + * + */ + typedef void + (*T1_Hints_OpenFunc)( T1_Hints hints ); + + + /************************************************************************** + * + * @functype: + * T1_Hints_SetStemFunc + * + * @description: + * A method of the @T1_Hints class used to record a new horizontal or + * vertical stem. This corresponds to the Type 1 'hstem' and 'vstem' + * operators. + * + * @input: + * hints :: + * A handle to the Type 1 hints recorder. + * + * dimension :: + * 0 for horizontal stems (hstem), 1 for vertical ones (vstem). + * + * coords :: + * Array of 2 coordinates in 16.16 format, used as (position,length) + * stem descriptor. + * + * @note: + * Use vertical coordinates (y) for horizontal stems (dim=0). Use + * horizontal coordinates (x) for vertical stems (dim=1). + * + * 'coords[0]' is the absolute stem position (lowest coordinate); + * 'coords[1]' is the length. + * + * The length can be negative, in which case it must be either -20 or + * -21. It is interpreted as a 'ghost' stem, according to the Type 1 + * specification. + * + * If the length is -21 (corresponding to a bottom ghost stem), then the + * real stem position is 'coords[0]+coords[1]'. + * + */ + typedef void + (*T1_Hints_SetStemFunc)( T1_Hints hints, + FT_UInt dimension, + FT_Fixed* coords ); + + + /************************************************************************** + * + * @functype: + * T1_Hints_SetStem3Func + * + * @description: + * A method of the @T1_Hints class used to record three + * counter-controlled horizontal or vertical stems at once. + * + * @input: + * hints :: + * A handle to the Type 1 hints recorder. + * + * dimension :: + * 0 for horizontal stems, 1 for vertical ones. + * + * coords :: + * An array of 6 values in 16.16 format, holding 3 (position,length) + * pairs for the counter-controlled stems. + * + * @note: + * Use vertical coordinates (y) for horizontal stems (dim=0). Use + * horizontal coordinates (x) for vertical stems (dim=1). + * + * The lengths cannot be negative (ghost stems are never + * counter-controlled). + * + */ + typedef void + (*T1_Hints_SetStem3Func)( T1_Hints hints, + FT_UInt dimension, + FT_Fixed* coords ); + + + /************************************************************************** + * + * @functype: + * T1_Hints_ResetFunc + * + * @description: + * A method of the @T1_Hints class used to reset the stems hints in a + * recording session. + * + * @input: + * hints :: + * A handle to the Type 1 hints recorder. + * + * end_point :: + * The index of the last point in the input glyph in which the + * previously defined hints apply. + * + */ + typedef void + (*T1_Hints_ResetFunc)( T1_Hints hints, + FT_UInt end_point ); + + + /************************************************************************** + * + * @functype: + * T1_Hints_CloseFunc + * + * @description: + * A method of the @T1_Hints class used to close a hint recording + * session. + * + * @input: + * hints :: + * A handle to the Type 1 hints recorder. + * + * end_point :: + * The index of the last point in the input glyph. + * + * @return: + * FreeType error code. 0 means success. + * + * @note: + * The error code is set to indicate that an error occurred during the + * recording session. + * + */ + typedef FT_Error + (*T1_Hints_CloseFunc)( T1_Hints hints, + FT_UInt end_point ); + + + /************************************************************************** + * + * @functype: + * T1_Hints_ApplyFunc + * + * @description: + * A method of the @T1_Hints class used to apply hints to the + * corresponding glyph outline. Must be called once all hints have been + * recorded. + * + * @input: + * hints :: + * A handle to the Type 1 hints recorder. + * + * outline :: + * A pointer to the target outline descriptor. + * + * globals :: + * The hinter globals for this font. + * + * hint_mode :: + * Hinting information. + * + * @return: + * FreeType error code. 0 means success. + * + * @note: + * On input, all points within the outline are in font coordinates. On + * output, they are in 1/64 of pixels. + * + * The scaling transformation is taken from the 'globals' object which + * must correspond to the same font as the glyph. + * + */ + typedef FT_Error + (*T1_Hints_ApplyFunc)( T1_Hints hints, + FT_Outline* outline, + PSH_Globals globals, + FT_Render_Mode hint_mode ); + + + /************************************************************************** + * + * @struct: + * T1_Hints_FuncsRec + * + * @description: + * The structure used to provide the API to @T1_Hints objects. + * + * @fields: + * hints :: + * A handle to the T1 Hints recorder. + * + * open :: + * The function to open a recording session. + * + * close :: + * The function to close a recording session. + * + * stem :: + * The function to set a simple stem. + * + * stem3 :: + * The function to set counter-controlled stems. + * + * reset :: + * The function to reset stem hints. + * + * apply :: + * The function to apply the hints to the corresponding glyph outline. + * + */ + typedef struct T1_Hints_FuncsRec_ + { + T1_Hints hints; + T1_Hints_OpenFunc open; + T1_Hints_CloseFunc close; + T1_Hints_SetStemFunc stem; + T1_Hints_SetStem3Func stem3; + T1_Hints_ResetFunc reset; + T1_Hints_ApplyFunc apply; + + } T1_Hints_FuncsRec; + + + /*************************************************************************/ + /*************************************************************************/ + /***** *****/ + /***** PUBLIC TYPE 2 HINTS RECORDER *****/ + /***** *****/ + /*************************************************************************/ + /*************************************************************************/ + + /************************************************************************** + * + * @type: + * T2_Hints + * + * @description: + * This is a handle to an opaque structure used to record glyph hints + * from a Type 2 character glyph character string. + * + * The methods used to operate on this object are defined by the + * @T2_Hints_FuncsRec structure. Recording glyph hints is normally + * achieved through the following scheme: + * + * - Open a new hint recording session by calling the 'open' method. + * This rewinds the recorder and prepare it for new input. + * + * - For each hint found in the glyph charstring, call the corresponding + * method ('stems', 'hintmask', 'counters'). Note that these functions + * do not return an error code. + * + * - Close the recording session by calling the 'close' method. It + * returns an error code if the hints were invalid or something strange + * happened (e.g., memory shortage). + * + * The hints accumulated in the object can later be used by the + * Postscript hinter. + * + */ + typedef struct T2_HintsRec_* T2_Hints; + + + /************************************************************************** + * + * @type: + * T2_Hints_Funcs + * + * @description: + * A pointer to the @T2_Hints_FuncsRec structure that defines the API of + * a given @T2_Hints object. + * + */ + typedef const struct T2_Hints_FuncsRec_* T2_Hints_Funcs; + + + /************************************************************************** + * + * @functype: + * T2_Hints_OpenFunc + * + * @description: + * A method of the @T2_Hints class used to prepare it for a new Type 2 + * hints recording session. + * + * @input: + * hints :: + * A handle to the Type 2 hints recorder. + * + * @note: + * You should always call the @T2_Hints_CloseFunc method in order to + * close an opened recording session. + * + */ + typedef void + (*T2_Hints_OpenFunc)( T2_Hints hints ); + + + /************************************************************************** + * + * @functype: + * T2_Hints_StemsFunc + * + * @description: + * A method of the @T2_Hints class used to set the table of stems in + * either the vertical or horizontal dimension. Equivalent to the + * 'hstem', 'vstem', 'hstemhm', and 'vstemhm' Type 2 operators. + * + * @input: + * hints :: + * A handle to the Type 2 hints recorder. + * + * dimension :: + * 0 for horizontal stems (hstem), 1 for vertical ones (vstem). + * + * count :: + * The number of stems. + * + * coords :: + * An array of 'count' (position,length) pairs in 16.16 format. + * + * @note: + * Use vertical coordinates (y) for horizontal stems (dim=0). Use + * horizontal coordinates (x) for vertical stems (dim=1). + * + * There are '2*count' elements in the 'coords' array. Each even element + * is an absolute position in font units, each odd element is a length in + * font units. + * + * A length can be negative, in which case it must be either -20 or -21. + * It is interpreted as a 'ghost' stem, according to the Type 1 + * specification. + * + */ + typedef void + (*T2_Hints_StemsFunc)( T2_Hints hints, + FT_UInt dimension, + FT_Int count, + FT_Fixed* coordinates ); + + + /************************************************************************** + * + * @functype: + * T2_Hints_MaskFunc + * + * @description: + * A method of the @T2_Hints class used to set a given hintmask (this + * corresponds to the 'hintmask' Type 2 operator). + * + * @input: + * hints :: + * A handle to the Type 2 hints recorder. + * + * end_point :: + * The glyph index of the last point to which the previously defined or + * activated hints apply. + * + * bit_count :: + * The number of bits in the hint mask. + * + * bytes :: + * An array of bytes modelling the hint mask. + * + * @note: + * If the hintmask starts the charstring (before any glyph point + * definition), the value of `end_point` should be 0. + * + * `bit_count` is the number of meaningful bits in the 'bytes' array; it + * must be equal to the total number of hints defined so far (i.e., + * horizontal+verticals). + * + * The 'bytes' array can come directly from the Type 2 charstring and + * respects the same format. + * + */ + typedef void + (*T2_Hints_MaskFunc)( T2_Hints hints, + FT_UInt end_point, + FT_UInt bit_count, + const FT_Byte* bytes ); + + + /************************************************************************** + * + * @functype: + * T2_Hints_CounterFunc + * + * @description: + * A method of the @T2_Hints class used to set a given counter mask (this + * corresponds to the 'hintmask' Type 2 operator). + * + * @input: + * hints :: + * A handle to the Type 2 hints recorder. + * + * end_point :: + * A glyph index of the last point to which the previously defined or + * active hints apply. + * + * bit_count :: + * The number of bits in the hint mask. + * + * bytes :: + * An array of bytes modelling the hint mask. + * + * @note: + * If the hintmask starts the charstring (before any glyph point + * definition), the value of `end_point` should be 0. + * + * `bit_count` is the number of meaningful bits in the 'bytes' array; it + * must be equal to the total number of hints defined so far (i.e., + * horizontal+verticals). + * + * The 'bytes' array can come directly from the Type 2 charstring and + * respects the same format. + * + */ + typedef void + (*T2_Hints_CounterFunc)( T2_Hints hints, + FT_UInt bit_count, + const FT_Byte* bytes ); + + + /************************************************************************** + * + * @functype: + * T2_Hints_CloseFunc + * + * @description: + * A method of the @T2_Hints class used to close a hint recording + * session. + * + * @input: + * hints :: + * A handle to the Type 2 hints recorder. + * + * end_point :: + * The index of the last point in the input glyph. + * + * @return: + * FreeType error code. 0 means success. + * + * @note: + * The error code is set to indicate that an error occurred during the + * recording session. + * + */ + typedef FT_Error + (*T2_Hints_CloseFunc)( T2_Hints hints, + FT_UInt end_point ); + + + /************************************************************************** + * + * @functype: + * T2_Hints_ApplyFunc + * + * @description: + * A method of the @T2_Hints class used to apply hints to the + * corresponding glyph outline. Must be called after the 'close' method. + * + * @input: + * hints :: + * A handle to the Type 2 hints recorder. + * + * outline :: + * A pointer to the target outline descriptor. + * + * globals :: + * The hinter globals for this font. + * + * hint_mode :: + * Hinting information. + * + * @return: + * FreeType error code. 0 means success. + * + * @note: + * On input, all points within the outline are in font coordinates. On + * output, they are in 1/64 of pixels. + * + * The scaling transformation is taken from the 'globals' object which + * must correspond to the same font than the glyph. + * + */ + typedef FT_Error + (*T2_Hints_ApplyFunc)( T2_Hints hints, + FT_Outline* outline, + PSH_Globals globals, + FT_Render_Mode hint_mode ); + + + /************************************************************************** + * + * @struct: + * T2_Hints_FuncsRec + * + * @description: + * The structure used to provide the API to @T2_Hints objects. + * + * @fields: + * hints :: + * A handle to the T2 hints recorder object. + * + * open :: + * The function to open a recording session. + * + * close :: + * The function to close a recording session. + * + * stems :: + * The function to set the dimension's stems table. + * + * hintmask :: + * The function to set hint masks. + * + * counter :: + * The function to set counter masks. + * + * apply :: + * The function to apply the hints on the corresponding glyph outline. + * + */ + typedef struct T2_Hints_FuncsRec_ + { + T2_Hints hints; + T2_Hints_OpenFunc open; + T2_Hints_CloseFunc close; + T2_Hints_StemsFunc stems; + T2_Hints_MaskFunc hintmask; + T2_Hints_CounterFunc counter; + T2_Hints_ApplyFunc apply; + + } T2_Hints_FuncsRec; + + + /* */ + + + typedef struct PSHinter_Interface_ + { + PSH_Globals_Funcs (*get_globals_funcs)( FT_Module module ); + T1_Hints_Funcs (*get_t1_funcs) ( FT_Module module ); + T2_Hints_Funcs (*get_t2_funcs) ( FT_Module module ); + + } PSHinter_Interface; + + typedef PSHinter_Interface* PSHinter_Service; + + +#define FT_DEFINE_PSHINTER_INTERFACE( \ + class_, \ + get_globals_funcs_, \ + get_t1_funcs_, \ + get_t2_funcs_ ) \ + static const PSHinter_Interface class_ = \ + { \ + get_globals_funcs_, \ + get_t1_funcs_, \ + get_t2_funcs_ \ + }; + + +FT_END_HEADER + +#endif /* PSHINTS_H_ */ + + +/* END */ |