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/***************************************************************************/
/* */
/* ttinterp.h */
/* */
/* TrueType bytecode interpreter (specification). */
/* */
/* Copyright 1996-2001, 2002, 2003, 2004, 2005, 2006, 2007, 2010 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 __TTINTERP_H__
#define __TTINTERP_H__
#include <ft2build.h>
#include "ttobjs.h"
FT_BEGIN_HEADER
#ifndef TT_CONFIG_OPTION_STATIC_INTERPRETER /* indirect implementation */
#define EXEC_OP_ TT_ExecContext exc,
#define EXEC_OP TT_ExecContext exc
#define EXEC_ARG_ exc,
#define EXEC_ARG exc
#else /* static implementation */
#define EXEC_OP_ /* void */
#define EXEC_OP /* void */
#define EXEC_ARG_ /* void */
#define EXEC_ARG /* void */
#endif /* TT_CONFIG_OPTION_STATIC_INTERPRETER */
/*************************************************************************/
/* */
/* Rounding mode constants. */
/* */
#define TT_Round_Off 5
#define TT_Round_To_Half_Grid 0
#define TT_Round_To_Grid 1
#define TT_Round_To_Double_Grid 2
#define TT_Round_Up_To_Grid 4
#define TT_Round_Down_To_Grid 3
#define TT_Round_Super 6
#define TT_Round_Super_45 7
/*************************************************************************/
/* */
/* Function types used by the interpreter, depending on various modes */
/* (e.g. the rounding mode, whether to render a vertical or horizontal */
/* line etc). */
/* */
/*************************************************************************/
/* Rounding function */
typedef FT_F26Dot6
(*TT_Round_Func)( EXEC_OP_ FT_F26Dot6 distance,
FT_F26Dot6 compensation );
/* Point displacement along the freedom vector routine */
typedef void
(*TT_Move_Func)( EXEC_OP_ TT_GlyphZone zone,
FT_UShort point,
FT_F26Dot6 distance );
/* Distance projection along one of the projection vectors */
typedef FT_F26Dot6
(*TT_Project_Func)( EXEC_OP_ FT_Pos dx,
FT_Pos dy );
/* reading a cvt value. Take care of non-square pixels if necessary */
typedef FT_F26Dot6
(*TT_Get_CVT_Func)( EXEC_OP_ FT_ULong idx );
/* setting or moving a cvt value. Take care of non-square pixels */
/* if necessary */
typedef void
(*TT_Set_CVT_Func)( EXEC_OP_ FT_ULong idx,
FT_F26Dot6 value );
/*************************************************************************/
/* */
/* This structure defines a call record, used to manage function calls. */
/* */
typedef struct TT_CallRec_
{
FT_Int Caller_Range;
FT_Long Caller_IP;
FT_Long Cur_Count;
FT_Long Cur_Restart;
} TT_CallRec, *TT_CallStack;
/*************************************************************************/
/* */
/* The main structure for the interpreter which collects all necessary */
/* variables and states. */
/* */
typedef struct TT_ExecContextRec_
{
TT_Face face;
TT_Size size;
FT_Memory memory;
/* instructions state */
FT_Error error; /* last execution error */
FT_Long top; /* top of exec. stack */
FT_UInt stackSize; /* size of exec. stack */
FT_Long* stack; /* current exec. stack */
FT_Long args;
FT_UInt new_top; /* new top after exec. */
TT_GlyphZoneRec zp0, /* zone records */
zp1,
zp2,
pts,
twilight;
FT_Size_Metrics metrics;
TT_Size_Metrics tt_metrics; /* size metrics */
TT_GraphicsState GS; /* current graphics state */
FT_Int curRange; /* current code range number */
FT_Byte* code; /* current code range */
FT_Long IP; /* current instruction pointer */
FT_Long codeSize; /* size of current range */
FT_Byte opcode; /* current opcode */
FT_Int length; /* length of current opcode */
FT_Bool step_ins; /* true if the interpreter must */
/* increment IP after ins. exec */
FT_ULong cvtSize;
FT_Long* cvt;
FT_UInt glyphSize; /* glyph instructions buffer size */
FT_Byte* glyphIns; /* glyph instructions buffer */
FT_UInt numFDefs; /* number of function defs */
FT_UInt maxFDefs; /* maximum number of function defs */
TT_DefArray FDefs; /* table of FDefs entries */
FT_UInt numIDefs; /* number of instruction defs */
FT_UInt maxIDefs; /* maximum number of ins defs */
TT_DefArray IDefs; /* table of IDefs entries */
FT_UInt maxFunc; /* maximum function index */
FT_UInt maxIns; /* maximum instruction index */
FT_Int callTop, /* top of call stack during execution */
callSize; /* size of call stack */
TT_CallStack callStack; /* call stack */
FT_UShort maxPoints; /* capacity of this context's `pts' */
FT_Short maxContours; /* record, expressed in points and */
/* contours. */
TT_CodeRangeTable codeRangeTable; /* table of valid code ranges */
/* useful for the debugger */
FT_UShort storeSize; /* size of current storage */
FT_Long* storage; /* storage area */
FT_F26Dot6 period; /* values used for the */
FT_F26Dot6 phase; /* `SuperRounding' */
FT_F26Dot6 threshold;
#if 0
/* this seems to be unused */
FT_Int cur_ppem; /* ppem along the current proj vector */
#endif
FT_Bool instruction_trap; /* If `True', the interpreter will */
/* exit after each instruction */
TT_GraphicsState default_GS; /* graphics state resulting from */
/* the prep program */
FT_Bool is_composite; /* true if the glyph is composite */
FT_Bool pedantic_hinting; /* true if pedantic interpretation */
/* latest interpreter additions */
FT_Long F_dot_P; /* dot product of freedom and projection */
/* vectors */
TT_Round_Func func_round; /* current rounding function */
TT_Project_Func func_project, /* current projection function */
func_dualproj, /* current dual proj. function */
func_freeProj; /* current freedom proj. func */
TT_Move_Func func_move; /* current point move function */
TT_Move_Func func_move_orig; /* move original position function */
TT_Get_CVT_Func func_read_cvt; /* read a cvt entry */
TT_Set_CVT_Func func_write_cvt; /* write a cvt entry (in pixels) */
TT_Set_CVT_Func func_move_cvt; /* incr a cvt entry (in pixels) */
FT_Bool grayscale; /* are we hinting for grayscale? */
} TT_ExecContextRec;
extern const TT_GraphicsState tt_default_graphics_state;
FT_LOCAL( FT_Error )
TT_Goto_CodeRange( TT_ExecContext exec,
FT_Int range,
FT_Long IP );
FT_LOCAL( FT_Error )
TT_Set_CodeRange( TT_ExecContext exec,
FT_Int range,
void* base,
FT_Long length );
FT_LOCAL( FT_Error )
TT_Clear_CodeRange( TT_ExecContext exec,
FT_Int range );
FT_LOCAL( FT_Error )
Update_Max( FT_Memory memory,
FT_ULong* size,
FT_Long multiplier,
void* _pbuff,
FT_ULong new_max );
/*************************************************************************/
/* */
/* <Function> */
/* TT_New_Context */
/* */
/* <Description> */
/* Queries the face context for a given font. Note that there is */
/* now a _single_ execution context in the TrueType driver which is */
/* shared among faces. */
/* */
/* <Input> */
/* face :: A handle to the source face object. */
/* */
/* <Return> */
/* A handle to the execution context. Initialized for `face'. */
/* */
/* <Note> */
/* Only the glyph loader and debugger should call this function. */
/* */
FT_EXPORT( TT_ExecContext )
TT_New_Context( TT_Driver driver );
FT_LOCAL( FT_Error )
TT_Done_Context( TT_ExecContext exec );
FT_LOCAL( FT_Error )
TT_Load_Context( TT_ExecContext exec,
TT_Face face,
TT_Size size );
FT_LOCAL( FT_Error )
TT_Save_Context( TT_ExecContext exec,
TT_Size ins );
FT_LOCAL( FT_Error )
TT_Run_Context( TT_ExecContext exec,
FT_Bool debug );
/*************************************************************************/
/* */
/* <Function> */
/* TT_RunIns */
/* */
/* <Description> */
/* Executes one or more instruction in the execution context. This */
/* is the main function of the TrueType opcode interpreter. */
/* */
/* <Input> */
/* exec :: A handle to the target execution context. */
/* */
/* <Return> */
/* FreeType error code. 0 means success. */
/* */
/* <Note> */
/* Only the object manager and debugger should call this function. */
/* */
/* This function is publicly exported because it is directly */
/* invoked by the TrueType debugger. */
/* */
FT_EXPORT( FT_Error )
TT_RunIns( TT_ExecContext exec );
FT_END_HEADER
#endif /* __TTINTERP_H__ */
/* END */
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