/***************************************************************************/

/*                                                                         */

/*  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 */