ttobjs.h
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上传日期:2020-08-09
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文件大小:20k
- /***************************************************************************/
- /* */
- /* ttobjs.h */
- /* */
- /* Objects manager (specification). */
- /* */
- /* Copyright 1996-2001, 2002, 2003, 2004, 2005, 2006, 2007 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 __TTOBJS_H__
- #define __TTOBJS_H__
- #include <ft2build.h>
- #include FT_INTERNAL_OBJECTS_H
- #include FT_INTERNAL_TRUETYPE_TYPES_H
- FT_BEGIN_HEADER
- /*************************************************************************/
- /* */
- /* <Type> */
- /* TT_Driver */
- /* */
- /* <Description> */
- /* A handle to a TrueType driver object. */
- /* */
- typedef struct TT_DriverRec_* TT_Driver;
- /*************************************************************************/
- /* */
- /* <Type> */
- /* TT_Instance */
- /* */
- /* <Description> */
- /* A handle to a TrueType size object. */
- /* */
- typedef struct TT_SizeRec_* TT_Size;
- /*************************************************************************/
- /* */
- /* <Type> */
- /* TT_GlyphSlot */
- /* */
- /* <Description> */
- /* A handle to a TrueType glyph slot object. */
- /* */
- /* <Note> */
- /* This is a direct typedef of FT_GlyphSlot, as there is nothing */
- /* specific about the TrueType glyph slot. */
- /* */
- typedef FT_GlyphSlot TT_GlyphSlot;
- /*************************************************************************/
- /* */
- /* <Struct> */
- /* TT_GraphicsState */
- /* */
- /* <Description> */
- /* The TrueType graphics state used during bytecode interpretation. */
- /* */
- typedef struct TT_GraphicsState_
- {
- FT_UShort rp0;
- FT_UShort rp1;
- FT_UShort rp2;
- FT_UnitVector dualVector;
- FT_UnitVector projVector;
- FT_UnitVector freeVector;
- #ifdef TT_CONFIG_OPTION_UNPATENTED_HINTING
- FT_Bool both_x_axis;
- #endif
- FT_Long loop;
- FT_F26Dot6 minimum_distance;
- FT_Int round_state;
- FT_Bool auto_flip;
- FT_F26Dot6 control_value_cutin;
- FT_F26Dot6 single_width_cutin;
- FT_F26Dot6 single_width_value;
- FT_Short delta_base;
- FT_Short delta_shift;
- FT_Byte instruct_control;
- FT_Bool scan_control;
- FT_Int scan_type;
- FT_UShort gep0;
- FT_UShort gep1;
- FT_UShort gep2;
- } TT_GraphicsState;
- #ifdef TT_USE_BYTECODE_INTERPRETER
- FT_LOCAL( void )
- tt_glyphzone_done( TT_GlyphZone zone );
- FT_LOCAL( FT_Error )
- tt_glyphzone_new( FT_Memory memory,
- FT_UShort maxPoints,
- FT_Short maxContours,
- TT_GlyphZone zone );
- #endif /* TT_USE_BYTECODE_INTERPRETER */
- /*************************************************************************/
- /* */
- /* EXECUTION SUBTABLES */
- /* */
- /* These sub-tables relate to instruction execution. */
- /* */
- /*************************************************************************/
- #define TT_MAX_CODE_RANGES 3
- /*************************************************************************/
- /* */
- /* There can only be 3 active code ranges at once: */
- /* - the Font Program */
- /* - the CVT Program */
- /* - a glyph's instructions set */
- /* */
- typedef enum TT_CodeRange_Tag_
- {
- tt_coderange_none = 0,
- tt_coderange_font,
- tt_coderange_cvt,
- tt_coderange_glyph
- } TT_CodeRange_Tag;
- typedef struct TT_CodeRange_
- {
- FT_Byte* base;
- FT_ULong size;
- } TT_CodeRange;
- typedef TT_CodeRange TT_CodeRangeTable[TT_MAX_CODE_RANGES];
- /*************************************************************************/
- /* */
- /* Defines a function/instruction definition record. */
- /* */
- typedef struct TT_DefRecord_
- {
- FT_Int range; /* in which code range is it located? */
- FT_Long start; /* where does it start? */
- FT_UInt opc; /* function #, or instruction code */
- FT_Bool active; /* is it active? */
- } TT_DefRecord, *TT_DefArray;
- /*************************************************************************/
- /* */
- /* Subglyph transformation record. */
- /* */
- typedef struct TT_Transform_
- {
- FT_Fixed xx, xy; /* transformation matrix coefficients */
- FT_Fixed yx, yy;
- FT_F26Dot6 ox, oy; /* offsets */
- } TT_Transform;
- /*************************************************************************/
- /* */
- /* Subglyph loading record. Used to load composite components. */
- /* */
- typedef struct TT_SubglyphRec_
- {
- FT_Long index; /* subglyph index; initialized with -1 */
- FT_Bool is_scaled; /* is the subglyph scaled? */
- FT_Bool is_hinted; /* should it be hinted? */
- FT_Bool preserve_pps; /* preserve phantom points? */
- FT_Long file_offset;
- FT_BBox bbox;
- FT_Pos left_bearing;
- FT_Pos advance;
- TT_GlyphZoneRec zone;
- FT_Long arg1; /* first argument */
- FT_Long arg2; /* second argument */
- FT_UShort element_flag; /* current load element flag */
- TT_Transform transform; /* transformation matrix */
- FT_Vector pp1, pp2; /* phantom points (horizontal) */
- FT_Vector pp3, pp4; /* phantom points (vertical) */
- } TT_SubGlyphRec, *TT_SubGlyph_Stack;
- /*************************************************************************/
- /* */
- /* A note regarding non-squared pixels: */
- /* */
- /* (This text will probably go into some docs at some time; for now, it */
- /* is kept here to explain some definitions in the TIns_Metrics */
- /* record). */
- /* */
- /* The CVT is a one-dimensional array containing values that control */
- /* certain important characteristics in a font, like the height of all */
- /* capitals, all lowercase letter, default spacing or stem width/height. */
- /* */
- /* These values are found in FUnits in the font file, and must be scaled */
- /* to pixel coordinates before being used by the CVT and glyph programs. */
- /* Unfortunately, when using distinct x and y resolutions (or distinct x */
- /* and y pointsizes), there are two possible scalings. */
- /* */
- /* A first try was to implement a `lazy' scheme where all values were */
- /* scaled when first used. However, while some values are always used */
- /* in the same direction, some others are used under many different */
- /* circumstances and orientations. */
- /* */
- /* I have found a simpler way to do the same, and it even seems to work */
- /* in most of the cases: */
- /* */
- /* - All CVT values are scaled to the maximum ppem size. */
- /* */
- /* - When performing a read or write in the CVT, a ratio factor is used */
- /* to perform adequate scaling. Example: */
- /* */
- /* x_ppem = 14 */
- /* y_ppem = 10 */
- /* */
- /* We choose ppem = x_ppem = 14 as the CVT scaling size. All cvt */
- /* entries are scaled to it. */
- /* */
- /* x_ratio = 1.0 */
- /* y_ratio = y_ppem/ppem (< 1.0) */
- /* */
- /* We compute the current ratio like: */
- /* */
- /* - If projVector is horizontal, */
- /* ratio = x_ratio = 1.0 */
- /* */
- /* - if projVector is vertical, */
- /* ratio = y_ratio */
- /* */
- /* - else, */
- /* ratio = sqrt( (proj.x * x_ratio) ^ 2 + (proj.y * y_ratio) ^ 2 ) */
- /* */
- /* Reading a cvt value returns */
- /* ratio * cvt[index] */
- /* */
- /* Writing a cvt value in pixels: */
- /* cvt[index] / ratio */
- /* */
- /* The current ppem is simply */
- /* ratio * ppem */
- /* */
- /*************************************************************************/
- /*************************************************************************/
- /* */
- /* Metrics used by the TrueType size and context objects. */
- /* */
- typedef struct TT_Size_Metrics_
- {
- /* for non-square pixels */
- FT_Long x_ratio;
- FT_Long y_ratio;
- FT_UShort ppem; /* maximum ppem size */
- FT_Long ratio; /* current ratio */
- FT_Fixed scale;
- FT_F26Dot6 compensations[4]; /* device-specific compensations */
- FT_Bool valid;
- FT_Bool rotated; /* `is the glyph rotated?'-flag */
- FT_Bool stretched; /* `is the glyph stretched?'-flag */
- } TT_Size_Metrics;
- /*************************************************************************/
- /* */
- /* TrueType size class. */
- /* */
- typedef struct TT_SizeRec_
- {
- FT_SizeRec root;
- /* we have our own copy of metrics so that we can modify */
- /* it without affecting auto-hinting (when used) */
- FT_Size_Metrics metrics;
- TT_Size_Metrics ttmetrics;
- FT_ULong strike_index; /* 0xFFFFFFFF to indicate invalid */
- #ifdef TT_USE_BYTECODE_INTERPRETER
- FT_UInt num_function_defs; /* number of function definitions */
- FT_UInt max_function_defs;
- TT_DefArray function_defs; /* table of function definitions */
- FT_UInt num_instruction_defs; /* number of ins. definitions */
- FT_UInt max_instruction_defs;
- TT_DefArray instruction_defs; /* table of ins. definitions */
- FT_UInt max_func;
- FT_UInt max_ins;
- TT_CodeRangeTable codeRangeTable;
- TT_GraphicsState GS;
- FT_ULong cvt_size; /* the scaled control value table */
- FT_Long* cvt;
- FT_UShort storage_size; /* The storage area is now part of */
- FT_Long* storage; /* the instance */
- TT_GlyphZoneRec twilight; /* The instance's twilight zone */
- /* debugging variables */
- /* When using the debugger, we must keep the */
- /* execution context tied to the instance */
- /* object rather than asking it on demand. */
- FT_Bool debug;
- TT_ExecContext context;
- FT_Bool bytecode_ready;
- FT_Bool cvt_ready;
- #endif /* TT_USE_BYTECODE_INTERPRETER */
- } TT_SizeRec;
- /*************************************************************************/
- /* */
- /* TrueType driver class. */
- /* */
- typedef struct TT_DriverRec_
- {
- FT_DriverRec root;
- TT_ExecContext context; /* execution context */
- TT_GlyphZoneRec zone; /* glyph loader points zone */
- void* extension_component;
- } TT_DriverRec;
- /* Note: All of the functions below (except tt_size_reset()) are used */
- /* as function pointers in a FT_Driver_ClassRec. Therefore their */
- /* parameters are of types FT_Face, FT_Size, etc., rather than TT_Face, */
- /* TT_Size, etc., so that the compiler can confirm that the types and */
- /* number of parameters are correct. In all cases the FT_xxx types are */
- /* cast to their TT_xxx counterparts inside the functions since FreeType */
- /* will always use the TT driver to create them. */
- /*************************************************************************/
- /* */
- /* Face functions */
- /* */
- FT_LOCAL( FT_Error )
- tt_face_init( FT_Stream stream,
- FT_Face ttface, /* TT_Face */
- FT_Int face_index,
- FT_Int num_params,
- FT_Parameter* params );
- FT_LOCAL( void )
- tt_face_done( FT_Face ttface ); /* TT_Face */
- /*************************************************************************/
- /* */
- /* Size functions */
- /* */
- FT_LOCAL( FT_Error )
- tt_size_init( FT_Size ttsize ); /* TT_Size */
- FT_LOCAL( void )
- tt_size_done( FT_Size ttsize ); /* TT_Size */
- #ifdef TT_USE_BYTECODE_INTERPRETER
- FT_LOCAL( FT_Error )
- tt_size_run_fpgm( TT_Size size );
- FT_LOCAL( FT_Error )
- tt_size_run_prep( TT_Size size );
- FT_LOCAL( FT_Error )
- tt_size_ready_bytecode( TT_Size size );
- #endif /* TT_USE_BYTECODE_INTERPRETER */
- FT_LOCAL( FT_Error )
- tt_size_reset( TT_Size size );
- /*************************************************************************/
- /* */
- /* Driver functions */
- /* */
- FT_LOCAL( FT_Error )
- tt_driver_init( FT_Module ttdriver ); /* TT_Driver */
- FT_LOCAL( void )
- tt_driver_done( FT_Module ttdriver ); /* TT_Driver */
- /*************************************************************************/
- /* */
- /* Slot functions */
- /* */
- FT_LOCAL( FT_Error )
- tt_slot_init( FT_GlyphSlot slot );
- FT_END_HEADER
- #endif /* __TTOBJS_H__ */
- /* END */