ftglyph.c

qt-embedded-2.3.8.tar.gz源码

/***************************************************************************/
/*                                                                         */
/*  ftglyph.c                                                              */
/*                                                                         */
/*    FreeType convenience functions to handle glyphs (body).              */
/*                                                                         */
/*  Copyright 1996-2000 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.                                        */
/*                                                                         */
/***************************************************************************/

  /*************************************************************************/
  /*                                                                       */
  /*  This file contains the definition of several convenience functions   */
  /*  that can be used by client applications to easily retrieve glyph     */
  /*  bitmaps and outlines from a given face.                              */
  /*                                                                       */
  /*  These functions should be optional if you are writing a font server  */
  /*  or text layout engine on top of FreeType.  However, they are pretty  */
  /*  handy for many other simple uses of the library.                     */
  /*                                                                       */
  /*************************************************************************/


#include <freetype/ftglyph.h>
#include <freetype/ftoutln.h>
#include <freetype/internal/ftobjs.h>


  /*************************************************************************/
  /*                                                                       */
  /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
  /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
  /* messages during execution.                                            */
  /*                                                                       */
#undef  FT_COMPONENT
#define FT_COMPONENT  trace_glyph


  /*************************************************************************/
  /*************************************************************************/
  /****                                                                 ****/
  /****   Convenience functions                                         ****/
  /****                                                                 ****/
  /*************************************************************************/
  /*************************************************************************/


  /* documentation is in ftglyph.h */

  FT_EXPORT_DEF( void )  FT_Matrix_Multiply( FT_Matrix*  a,
                                             FT_Matrix*  b )
  {
    FT_Fixed  xx, xy, yx, yy;


    if ( !a || !b )
      return;

    xx = FT_MulFix( a->xx, b->xx ) + FT_MulFix( a->xy, b->yx );
    xy = FT_MulFix( a->xx, b->xy ) + FT_MulFix( a->xy, b->yy );
    yx = FT_MulFix( a->yx, b->xx ) + FT_MulFix( a->yy, b->yx );
    yy = FT_MulFix( a->yx, b->xy ) + FT_MulFix( a->yy, b->yy );

    b->xx = xx;  b->xy = xy;
    b->yx = yx;  b->yy = yy;
  }


  /* documentation is in ftglyph.h */

  FT_EXPORT_DEF( FT_Error )  FT_Matrix_Invert( FT_Matrix*  matrix )
  {
    FT_Pos  delta, xx, yy;


    if ( !matrix )
      return FT_Err_Invalid_Argument;

    /* compute discriminant */
    delta = FT_MulFix( matrix->xx, matrix->yy ) -
            FT_MulFix( matrix->xy, matrix->yx );

    if ( !delta )
      return FT_Err_Invalid_Argument;  /* matrix can't be inverted */

    matrix->xy = - FT_DivFix( matrix->xy, delta );
    matrix->yx = - FT_DivFix( matrix->yx, delta );

    xx = matrix->xx;
    yy = matrix->yy;

    matrix->xx = FT_DivFix( yy, delta );
    matrix->yy = FT_DivFix( xx, delta );

    return FT_Err_Ok;
  }


  /*************************************************************************/
  /*************************************************************************/
  /****                                                                 ****/
  /****   FT_BitmapGlyph support                                        ****/
  /****                                                                 ****/
  /*************************************************************************/
  /*************************************************************************/

  static
  FT_Error  ft_bitmap_copy( FT_Memory   memory,
                            FT_Bitmap*  source,
                            FT_Bitmap*  target )
  {
    FT_Error  error;
    FT_Int    pitch = source->pitch;
    FT_ULong  size;


    *target = *source;

    if ( pitch < 0 )
      pitch = -pitch;

    size = (FT_ULong)( pitch * source->rows );

    if ( !ALLOC( target->buffer, size ) )
      MEM_Copy( target->buffer, source->buffer, size );

    return error;
  }


  static
  FT_Error  ft_bitmap_glyph_init( FT_BitmapGlyph  glyph,
                                  FT_GlyphSlot    slot )
  {
    FT_Error    error   = FT_Err_Ok;
    FT_Library  library = FT_GLYPH(glyph)->library;
    FT_Memory   memory  = library->memory;


    if ( slot->format != ft_glyph_format_bitmap )
    {
      error = FT_Err_Invalid_Glyph_Format;
      goto Exit;
    }

    /* grab the bitmap in the slot - do lazy copying whenever possible */
    glyph->bitmap = slot->bitmap;
    glyph->left   = slot->bitmap_left;
    glyph->top    = slot->bitmap_top;

    if ( slot->flags & ft_glyph_own_bitmap )
      slot->flags &= ~ft_glyph_own_bitmap;
    else
    {
      /* copy the bitmap into a new buffer */
      error = ft_bitmap_copy( memory, &slot->bitmap, &glyph->bitmap );
    }

  Exit:
    return error;
  }


  static
  FT_Error  ft_bitmap_glyph_copy( FT_BitmapGlyph  source,
                                  FT_BitmapGlyph  target )
  {
    FT_Memory  memory = source->root.library->memory;


    target->left = source->left;
    target->top  = source->top;

    return ft_bitmap_copy( memory, &source->bitmap, &target->bitmap );
  }


  static
  void  ft_bitmap_glyph_done( FT_BitmapGlyph  glyph )
  {
    FT_Memory  memory = FT_GLYPH(glyph)->library->memory;


    FREE( glyph->bitmap.buffer );
  }


  static
  void  ft_bitmap_glyph_bbox( FT_BitmapGlyph  glyph,
                              FT_BBox*        cbox )
  {
    cbox->xMin = glyph->left << 6;
    cbox->xMax = cbox->xMin + ( glyph->bitmap.width << 6 );
    cbox->yMax = glyph->top << 6;
    cbox->yMin = cbox->yMax - ( glyph->bitmap.rows << 6 );
  }


  const FT_Glyph_Class  ft_bitmap_glyph_class =
  {
    sizeof( FT_BitmapGlyphRec ),
    ft_glyph_format_bitmap,

    (FT_Glyph_Init_Func)     ft_bitmap_glyph_init,
    (FT_Glyph_Done_Func)     ft_bitmap_glyph_done,
    (FT_Glyph_Copy_Func)     ft_bitmap_glyph_copy,
    (FT_Glyph_Transform_Func)0,
    (FT_Glyph_BBox_Func)     ft_bitmap_glyph_bbox,
    (FT_Glyph_Prepare_Func)  0
  };


  /*************************************************************************/
  /*************************************************************************/
  /****                                                                 ****/
  /****   FT_OutlineGlyph support                                       ****/
  /****                                                                 ****/
  /*************************************************************************/
  /*************************************************************************/


  static
  FT_Error  ft_outline_glyph_init( FT_OutlineGlyph  glyph,
                                   FT_GlyphSlot     slot )
  {
    FT_Error     error   = FT_Err_Ok;
    FT_Library   library = FT_GLYPH(glyph)->library;
    FT_Outline*  source  = &slot->outline;
    FT_Outline*  target  = &glyph->outline;


    /* check format in glyph slot */
    if ( slot->format != ft_glyph_format_outline )
    {
      error = FT_Err_Invalid_Glyph_Format;
      goto Exit;
    }

    /* allocate new outline */
    error = FT_Outline_New( library, source->n_points, source->n_contours,
                            &glyph->outline );
    if ( error )
      goto Exit;

    /* copy it */
    MEM_Copy( target->points, source->points,
              source->n_points * sizeof ( FT_Vector ) );

    MEM_Copy( target->tags, source->tags,
              source->n_points * sizeof ( FT_Byte ) );

    MEM_Copy( target->contours, source->contours,
              source->n_contours * sizeof ( FT_Short ) );

    /* copy all flags, except the `ft_outline_owner' one */
    target->flags = source->flags | ft_outline_owner;

  Exit:
    return error;
  }


  static
  void  ft_outline_glyph_done( FT_OutlineGlyph  glyph )
  {
    FT_Outline_Done( FT_GLYPH( glyph )->library, &glyph->outline );
  }


  static
  FT_Error  ft_outline_glyph_copy( FT_OutlineGlyph  source,
                                   FT_OutlineGlyph  target )
  {
    FT_Error    error;
    FT_Library  library = FT_GLYPH( source )->library;


    error = FT_Outline_New( library, source->outline.n_points,
                            source->outline.n_contours, &target->outline );
    if ( !error )
      FT_Outline_Copy( &source->outline, &target->outline );

    return error;
  }


  static
  void  ft_outline_glyph_transform( FT_OutlineGlyph  glyph,
                                    FT_Matrix*       matrix,
                                    FT_Vector*       delta )
  {
    if ( matrix )
      FT_Outline_Transform( &glyph->outline, matrix );

    if ( delta )
      FT_Outline_Translate( &glyph->outline, delta->x, delta->y );
  }


  static
  void  ft_outline_glyph_bbox( FT_OutlineGlyph  glyph,
                               FT_BBox*         bbox )
  {
    FT_Outline_Get_CBox( &glyph->outline, bbox );
  }


  static
  FT_Error  ft_outline_glyph_prepare( FT_OutlineGlyph  glyph,
                                      FT_GlyphSlot     slot )
  {
    slot->format         = ft_glyph_format_outline;
    slot->outline        = glyph->outline;
    slot->outline.flags &= ~ft_outline_owner;

    return FT_Err_Ok;
  }


  const FT_Glyph_Class  ft_outline_glyph_class =
  {
    sizeof( FT_OutlineGlyphRec ),
    ft_glyph_format_outline,