ttinterp.c

Qt/Embedded是一个多平台的C++图形用户界面应用程序框架

  /* <Function>                                                            */
  /*    TT_Clear_CodeRange                                                 */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Clears a code range.                                               */
  /*                                                                       */
  /* <Input>                                                               */
  /*    range :: The code range index.                                     */
  /*                                                                       */
  /* <InOut>                                                               */
  /*    exec  :: The target execution context.                             */
  /*                                                                       */
  /* <Return>                                                              */
  /*   TrueType error code.  0 means success.                              */
  /*                                                                       */
  /* <Note>                                                                */
  /*    Does not set the Error variable.                                   */
  /*                                                                       */
  EXPORT_FUNC
  TT_Error  TT_Clear_CodeRange( TT_ExecContext  exec,
                                TT_Int          range )
  {
    FT_Assert( range >= 1 && range <= 3 );

    exec->codeRangeTable[range - 1].base = NULL;
    exec->codeRangeTable[range - 1].size = 0;

    return TT_Err_Ok;
  }


  /*************************************************************************/
  /*                                                                       */
  /*                   EXECUTION CONTEXT ROUTINES                          */
  /*                                                                       */
  /*************************************************************************/


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    TT_Destroy_Context                                                 */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Destroys a given context.                                          */
  /*                                                                       */
  /* <Input>                                                               */
  /*    exec   :: A handle to the target execution context.                */
  /*    system :: A handle to the parent system object.                    */
  /*                                                                       */
  /* <Return>                                                              */
  /*    TrueType error code.  0 means success.                             */
  /*                                                                       */
  /* <Note>                                                                */
  /*    Only the glyph loader and debugger should call this function.      */
  /*                                                                       */
  LOCAL_FUNC
  TT_Error  TT_Destroy_Context( TT_ExecContext  exec,
                                FT_Memory       memory )
  {
    /* free composite load stack */
    FREE( exec->loadStack );
    exec->loadSize = 0;

    /* points zone */
    exec->maxPoints   = 0;
    exec->maxContours = 0;

    /* free stack */
    FREE( exec->stack );
    exec->stackSize = 0;

    /* free call stack */
    FREE( exec->callStack );
    exec->callSize = 0;
    exec->callTop  = 0;

    /* free glyph code range */
    FREE( exec->glyphIns );
    exec->glyphSize = 0;

    exec->size = NULL;
    exec->face = NULL;

    FREE( exec );
    return TT_Err_Ok;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    Init_Context                                                       */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Initializes a context object.                                      */
  /*                                                                       */
  /* <Input>                                                               */
  /*    memory :: A handle to the parent memory object.                    */
  /*                                                                       */
  /*    face   :: A handle to the source TrueType face object.             */
  /*                                                                       */
  /* <InOut>                                                               */
  /*    exec   :: A handle to the target execution context.                */
  /*                                                                       */
  /* <Return>                                                              */
  /*    TrueType error code.  0 means success.                             */
  /*                                                                       */
  static
  TT_Error  Init_Context( TT_ExecContext  exec,
                          TT_Face         face,
                          FT_Memory       memory )
  {
    TT_Error  error;


    FT_TRACE1(( "TT.Create_Create: new object at 0x%08lx, parent = 0x%08lx\n",
              (long)exec, (long)face ));

    /* XXX: We don't reserve arrays anymore, this is done automatically */
    /*      during a call to Context_Load().                            */

    exec->memory   = memory;
    exec->callSize = 32;

    if ( ALLOC_ARRAY( exec->callStack, exec->callSize, TT_CallRec ) )
      goto Fail_Memory;

    /* all values in the context are set to 0 already, but this is */
    /* here as a remainder                                         */
    exec->maxPoints   = 0;
    exec->maxContours = 0;

    exec->stackSize = 0;
    exec->loadSize  = 0;
    exec->glyphSize = 0;

    exec->stack     = NULL;
    exec->loadStack = NULL;
    exec->glyphIns  = NULL;

    exec->face = face;
    exec->size = NULL;

    return TT_Err_Ok;

  Fail_Memory:
    FT_ERROR(( "TT.Context_Create: not enough memory for 0x%08lx\n",
             (long)exec ));
    TT_Destroy_Context( exec, memory );

    return error;
 }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    Update_Max                                                         */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Checks the size of a buffer and reallocates it if necessary.       */
  /*                                                                       */
  /* <Input>                                                               */
  /*    multiplier :: The size in bytes of each element in the buffer.     */
  /*                                                                       */
  /*    new_max    :: The new capacity (size) of the buffer.               */
  /*                                                                       */
  /* <InOut>                                                               */
  /*    size       :: The address of the buffer's current size expressed   */
  /*                  in elements.                                         */
  /*                                                                       */
  /*    buff       :: The address of the buffer base pointer.              */
  /*                                                                       */
  /* <Return>                                                              */
  /*    TrueType error code.  0 means success.                             */
  /*                                                                       */
  static
  TT_Error  Update_Max( FT_Memory  memory,
                        TT_ULong*  size,
                        TT_Long    multiplier,
                        void**     buff,
                        TT_ULong   new_max )
  {
    TT_Error  error;


    if ( *size < new_max )
    {
      FREE( *buff );
      if ( ALLOC( *buff, new_max * multiplier ) )
        return error;
      *size = new_max;
    }

    return TT_Err_Ok;
  }



  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    TT_Load_Context                                                    */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Prepare an execution context for glyph hinting.                    */
  /*                                                                       */
  /* <Input>                                                               */
  /*    face :: A handle to the source face object.                        */
  /*    size :: A handle to the source size object.                        */
  /*                                                                       */
  /* <InOut>                                                               */
  /*    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_Load_Context( TT_ExecContext  exec,
                             TT_Face         face,
                             TT_Size         size )
  {
    TT_Int          i;
    TT_ULong        tmp;
    TT_MaxProfile*  maxp;
    TT_Error        error;

    exec->face = face;
    maxp       = &face->max_profile;
    exec->size = size;

    if ( size )
    {
      exec->numFDefs   = size->num_function_defs;
      exec->maxFDefs   = size->max_function_defs;
      exec->numIDefs   = size->num_instruction_defs;
      exec->maxIDefs   = size->max_instruction_defs;
      exec->FDefs      = size->function_defs;
      exec->IDefs      = size->instruction_defs;
      exec->tt_metrics = size->ttmetrics;
      exec->metrics    = size->root.metrics;

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

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

      /* set graphics state */
      exec->GS = size->GS;

      exec->cvtSize = size->cvt_size;
      exec->cvt     = size->cvt;

      exec->storeSize = size->storage_size;
      exec->storage   = size->storage;

      exec->twilight  = size->twilight;
    }

    error = Update_Max( exec->memory,
                        &exec->loadSize,
                        sizeof ( TT_SubGlyphRec ),
                        (void**)&exec->loadStack,
                        exec->face->max_components + 1 );
    if ( error )
      return error;

    /* XXX: We reserve a little more elements on the stack to deal safely */
    /*      with broken fonts like arialbs, courbs, timesbs, etc.         */
    tmp = exec->stackSize;
    error = Update_Max( exec->memory,
                        &tmp,
                        sizeof ( TT_F26Dot6 ),
                        (void**)&exec->stack,
                        maxp->maxStackElements + 32 );
    exec->stackSize = (TT_UInt)tmp;
    if ( error )
      return error;

    tmp = exec->glyphSize;
    error = Update_Max( exec->memory,
                        &tmp,
                        sizeof ( TT_Byte ),
                        (void**)&exec->glyphIns,
                        maxp->maxSizeOfInstructions );
    exec->glyphSize = (TT_UShort)tmp;
    if ( error )
      return error;

    exec->pts.n_points   = 0;
    exec->pts.n_contours = 0;

    exec->instruction_trap = FALSE;

    return TT_Err_Ok;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    TT_Save_Context                                                    */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Saves the code ranges in a `size' object.                          */
  /*                                                                       */
  /* <Input>                                                               */
  /*    exec :: A handle to the source execution context.                  */
  /*                                                                       */
  /* <Output>                                                              */
  /*    ins  :: A handle to the target size object.                        */
  /*                                                                       */
  /* <Return>                                                              */
  /*    TrueType error code.  0 means success.                             */
  /*                                                                       */