ttinterp.c

Qt/Embedded是一个多平台的C++图形用户界面应用程序框架

  /* <Note>                                                                */
  /*    Only the glyph loader and debugger should call this function.      */
  /*                                                                       */
  EXPORT_FUNC
  TT_Error  TT_Save_Context( TT_ExecContext  exec,
                             TT_Size         size )
  {
    TT_Int  i;

    /* XXXX: Will probably disappear soon with all the code range */
    /*       management, which is now rather obsolete.            */
    /*                                                            */
    size->num_function_defs    = exec->numFDefs;
    size->num_instruction_defs = exec->numIDefs;

    size->max_func = exec->maxFunc;
    size->max_ins  = exec->maxIns;

    for ( i = 0; i < TT_MAX_CODE_RANGES; i++ )
      size->codeRangeTable[i] = exec->codeRangeTable[i];

    return TT_Err_Ok;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    TT_Run_Context                                                     */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Executes one or more instructions in the execution context.        */
  /*                                                                       */
  /* <Input>                                                               */
  /*    debug :: A Boolean flag.  If set, the function sets some internal  */
  /*             variables and returns immediately, otherwise TT_RunIns()  */
  /*             is called.                                                */
  /*                                                                       */
  /* <Input>                                                               */
  /*    exec  :: A handle to the target execution context.                 */
  /*                                                                       */
  /* <Return>                                                              */
  /*    TrueTyoe error code.  0 means success.                             */
  /*                                                                       */
  /* <Note>                                                                */
  /*    Only the glyph loader and debugger should call this function.      */
  /*                                                                       */
  EXPORT_FUNC
  TT_Error  TT_Run_Context( TT_ExecContext  exec,
                            TT_Bool         debug )
  {
    TT_Error  error;

    if ( (error = TT_Goto_CodeRange( exec, tt_coderange_glyph, 0 ))
           != TT_Err_Ok )
      return error;

    exec->zp0 = exec->pts;
    exec->zp1 = exec->pts;
    exec->zp2 = exec->pts;

    exec->GS.gep0 = 1;
    exec->GS.gep1 = 1;
    exec->GS.gep2 = 1;

    exec->GS.projVector.x = 0x4000;
    exec->GS.projVector.y = 0x0000;

    exec->GS.freeVector = exec->GS.projVector;
    exec->GS.dualVector = exec->GS.projVector;

    exec->GS.round_state = 1;
    exec->GS.loop        = 1;

    /* some glyphs leave something on the stack. so we clean it */
    /* before a new execution.                                  */
    exec->top     = 0;
    exec->callTop = 0;

#if 1
    return exec->face->interpreter( exec );
#else
    if ( !debug )
      return TT_RunIns( exec );
    else
      return TT_Err_Ok;
#endif
  }


  LOCAL_FUNC
  const TT_GraphicsState  tt_default_graphics_state =
  {
    0, 0, 0,
    { 0x4000, 0 },
    { 0x4000, 0 },
    { 0x4000, 0 },
    1, 64, 1,
    TRUE, 68, 0, 0, 9, 3,
    0, FALSE, 2, 1, 1, 1
  };


  /*************************************************************************/
  /*                                                                       */
  /* <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.      */
  /*                                                                       */
  EXPORT_FUNC
  TT_ExecContext  TT_New_Context( TT_Face  face )
  {
    TT_Driver       driver = (TT_Driver)face->root.driver;
    TT_ExecContext  exec;
    FT_Memory       memory = driver->root.memory;


    exec = driver->context;

    if ( !driver->context )
    {
      TT_Error   error;


      /* allocate object */
      if ( ALLOC( exec, sizeof ( *exec ) ) )
        goto Exit;

      /* initialize it */
      error = Init_Context( exec, face, memory );
      if ( error )
        goto Fail;

      /* store it into the driver */
      driver->context = exec;
    }

  Exit:
    return driver->context;

  Fail:
    FREE( exec );

    return 0;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    TT_Done_Context                                                    */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Discards an execution context.                                     */
  /*                                                                       */
  /* <Input>                                                               */
  /*    exec :: A handle to the target execution context.                  */
  /*                                                                       */
  /* <Return>                                                              */
  /*    TrueType error code.  0 means success.                             */
  /*                                                                       */
  /* <Note>                                                                */
  /*    Only the glyph loader and debugger should call this function.      */
  /*                                                                       */
  EXPORT_FUNC
  TT_Error  TT_Done_Context( TT_ExecContext  exec )
  {
    /* Nothing at all for now */
    UNUSED( exec );

    return TT_Err_Ok;
  }


  /*************************************************************************/
  /*                                                                       */
  /* Before an opcode is executed, the interpreter verifies that there are */
  /* enough arguments on the stack, with the help of the Pop_Push_Count    */
  /* table.                                                                */
  /*                                                                       */
  /* For each opcode, the first column gives the number of arguments that  */
  /* are popped from the stack; the second one gives the number of those   */
  /* that are pushed in result.                                            */
  /*                                                                       */
  /* Note that for opcodes with a varying number of parameters, either 0   */
  /* or 1 arg is verified before execution, depending on the nature of the */
  /* instruction:                                                          */
  /*                                                                       */
  /* - if the number of arguments is given by the bytecode stream or the   */
  /*   loop variable, 0 is chosen.                                         */
  /*                                                                       */
  /* - if the first argument is a count n that is followed by arguments    */
  /*   a1 .. an, then 1 is chosen.                                         */
  /*                                                                       */
  /*************************************************************************/


#undef  PACK
#define PACK( x, y )  ((x << 4) | y)


  static
  const TT_Byte  Pop_Push_Count[256] =
  {
    /* opcodes are gathered in groups of 16 */
    /* please keep the spaces as they are   */

    /*  SVTCA  y  */  PACK( 0, 0 ),
    /*  SVTCA  x  */  PACK( 0, 0 ),
    /*  SPvTCA y  */  PACK( 0, 0 ),
    /*  SPvTCA x  */  PACK( 0, 0 ),
    /*  SFvTCA y  */  PACK( 0, 0 ),
    /*  SFvTCA x  */  PACK( 0, 0 ),
    /*  SPvTL //  */  PACK( 2, 0 ),
    /*  SPvTL +   */  PACK( 2, 0 ),
    /*  SFvTL //  */  PACK( 2, 0 ),
    /*  SFvTL +   */  PACK( 2, 0 ),
    /*  SPvFS     */  PACK( 2, 0 ),
    /*  SFvFS     */  PACK( 2, 0 ),
    /*  GPV       */  PACK( 0, 2 ),
    /*  GFV       */  PACK( 0, 2 ),
    /*  SFvTPv    */  PACK( 0, 0 ),
    /*  ISECT     */  PACK( 5, 0 ),

    /*  SRP0      */  PACK( 1, 0 ),
    /*  SRP1      */  PACK( 1, 0 ),
    /*  SRP2      */  PACK( 1, 0 ),
    /*  SZP0      */  PACK( 1, 0 ),
    /*  SZP1      */  PACK( 1, 0 ),
    /*  SZP2      */  PACK( 1, 0 ),
    /*  SZPS      */  PACK( 1, 0 ),
    /*  SLOOP     */  PACK( 1, 0 ),
    /*  RTG       */  PACK( 0, 0 ),
    /*  RTHG      */  PACK( 0, 0 ),
    /*  SMD       */  PACK( 1, 0 ),
    /*  ELSE      */  PACK( 0, 0 ),
    /*  JMPR      */  PACK( 1, 0 ),
    /*  SCvTCi    */  PACK( 1, 0 ),
    /*  SSwCi     */  PACK( 1, 0 ),
    /*  SSW       */  PACK( 1, 0 ),

    /*  DUP       */  PACK( 1, 2 ),
    /*  POP       */  PACK( 1, 0 ),
    /*  CLEAR     */  PACK( 0, 0 ),
    /*  SWAP      */  PACK( 2, 2 ),
    /*  DEPTH     */  PACK( 0, 1 ),
    /*  CINDEX    */  PACK( 1, 1 ),
    /*  MINDEX    */  PACK( 1, 0 ),
    /*  AlignPTS  */  PACK( 2, 0 ),
    /*  INS_$28   */  PACK( 0, 0 ),
    /*  UTP       */  PACK( 1, 0 ),
    /*  LOOPCALL  */  PACK( 2, 0 ),
    /*  CALL      */  PACK( 1, 0 ),
    /*  FDEF      */  PACK( 1, 0 ),
    /*  ENDF      */  PACK( 0, 0 ),
    /*  MDAP[0]   */  PACK( 1, 0 ),
    /*  MDAP[1]   */  PACK( 1, 0 ),

    /*  IUP[0]    */  PACK( 0, 0 ),
    /*  IUP[1]    */  PACK( 0, 0 ),
    /*  SHP[0]    */  PACK( 0, 0 ),
    /*  SHP[1]    */  PACK( 0, 0 ),
    /*  SHC[0]    */  PACK( 1, 0 ),
    /*  SHC[1]    */  PACK( 1, 0 ),
    /*  SHZ[0]    */  PACK( 1, 0 ),
    /*  SHZ[1]    */  PACK( 1, 0 ),
    /*  SHPIX     */  PACK( 1, 0 ),
    /*  IP        */  PACK( 0, 0 ),
    /*  MSIRP[0]  */  PACK( 2, 0 ),
    /*  MSIRP[1]  */  PACK( 2, 0 ),
    /*  AlignRP   */  PACK( 0, 0 ),
    /*  RTDG      */  PACK( 0, 0 ),
    /*  MIAP[0]   */  PACK( 2, 0 ),
    /*  MIAP[1]   */  PACK( 2, 0 ),

    /*  NPushB    */  PACK( 0, 0 ),
    /*  NPushW    */  PACK( 0, 0 ),
    /*  WS        */  PACK( 2, 0 ),
    /*  RS        */  PACK( 1, 1 ),
    /*  WCvtP     */  PACK( 2, 0 ),
    /*  RCvt      */  PACK( 1, 1 ),
    /*  GC[0]     */  PACK( 1, 1 ),
    /*  GC[1]     */  PACK( 1, 1 ),
    /*  SCFS      */  PACK( 2, 0 ),
    /*  MD[0]     */  PACK( 2, 1 ),
    /*  MD[1]     */  PACK( 2, 1 ),
    /*  MPPEM     */  PACK( 0, 1 ),
    /*  MPS       */  PACK( 0, 1 ),
    /*  FlipON    */  PACK( 0, 0 ),
    /*  FlipOFF   */  PACK( 0, 0 ),
    /*  DEBUG     */  PACK( 1, 0 ),

    /*  LT        */  PACK( 2, 1 ),
    /*  LTEQ      */  PACK( 2, 1 ),
    /*  GT        */  PACK( 2, 1 ),
    /*  GTEQ      */  PACK( 2, 1 ),
    /*  EQ        */  PACK( 2, 1 ),
    /*  NEQ       */  PACK( 2, 1 ),
    /*  ODD       */  PACK( 1, 1 ),
    /*  EVEN      */  PACK( 1, 1 ),
    /*  IF        */  PACK( 1, 0 ),
    /*  EIF       */  PACK( 0, 0 ),
    /*  AND       */  PACK( 2, 1 ),
    /*  OR        */  PACK( 2, 1 ),
    /*  NOT       */  PACK( 1, 1 ),
    /*  DeltaP1   */  PACK( 1, 0 ),
    /*  SDB       */  PACK( 1, 0 ),