ttgload.h File Reference

#include <ft2build.h>
#include "ttobjs.h"

Include dependency graph for ttgload.h:

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Go to the source code of this file.

Functions
FT_BEGIN_HEADER	TT_Init_Glyph_Loading (TT_Face face)
	TT_Get_HMetrics (TT_Face face, FT_UInt idx, FT_Short *lsb, FT_UShort *aw)
	TT_Get_VMetrics (TT_Face face, FT_UInt idx, FT_Pos yMax, FT_Short *tsb, FT_UShort *ah)
	TT_Load_Glyph (TT_Size size, TT_GlyphSlot glyph, FT_UInt glyph_index, FT_Int32 load_flags)

Function Documentation

TT_Get_HMetrics()

TT_Get_HMetrics	(	TT_Face	face,
		FT_UInt	idx,
		FT_Short *	lsb,
		FT_UShort *	aw
	)

Definition at line 75 of file ttgload.c.

  {
    ( (SFNT_Service)face->sfnt )->get_metrics( face, 0, idx, lsb, aw );

    FT_TRACE5(( "  advance width (font units): %d\n", *aw ));
    FT_TRACE5(( "  left side bearing (font units): %d\n", *lsb ));
  }

Referenced by tt_get_metrics(), and TT_Load_Glyph().

TT_Get_VMetrics()

TT_Get_VMetrics	(	TT_Face	face,
		FT_UInt	idx,
		FT_Pos	yMax,
		FT_Short *	tsb,
		FT_UShort *	ah
	)

Definition at line 93 of file ttgload.c.

  {
    if ( face->vertical_info )
      ( (SFNT_Service)face->sfnt )->get_metrics( face, 1, idx, tsb, ah );

    else if ( face->os2.version != 0xFFFFU )
    {
      *tsb = (FT_Short)( face->os2.sTypoAscender - yMax );
      *ah  = (FT_UShort)FT_ABS( face->os2.sTypoAscender -
                                face->os2.sTypoDescender );
    }

    else
    {
      *tsb = (FT_Short)( face->horizontal.Ascender - yMax );
      *ah  = (FT_UShort)FT_ABS( face->horizontal.Ascender -
                                face->horizontal.Descender );
    }

    FT_TRACE5(( "  advance height (font units): %d\n", *ah ));
    FT_TRACE5(( "  top side bearing (font units): %d\n", *tsb ));
  }

Referenced by tt_get_metrics(), and TT_Load_Glyph().

TT_Init_Glyph_Loading()

FT_BEGIN_HEADER TT_Init_Glyph_Loading

(

TT_Face

face

)

Definition at line 742 of file ttgload.c.

  {
    face->access_glyph_frame   = TT_Access_Glyph_Frame;
    face->read_glyph_header    = TT_Load_Glyph_Header;
    face->read_simple_glyph    = TT_Load_Simple_Glyph;
    face->read_composite_glyph = TT_Load_Composite_Glyph;
    face->forget_glyph_frame   = TT_Forget_Glyph_Frame;
  }

Referenced by tt_face_init().

TT_Load_Glyph()

TT_Load_Glyph	(	TT_Size	size,
		TT_GlyphSlot	glyph,
		FT_UInt	glyph_index,
		FT_Int32	load_flags
	)

Definition at line 2687 of file ttgload.c.

  {
    FT_Error      error;
    TT_LoaderRec  loader;

#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
#define IS_DEFAULT_INSTANCE  ( !( FT_IS_NAMED_INSTANCE( glyph->face ) ||  \
                                  FT_IS_VARIATION( glyph->face )      ) )
#else
#define IS_DEFAULT_INSTANCE  1
#endif


    FT_TRACE1(( "TT_Load_Glyph: glyph index %d\n", glyph_index ));

#ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS

    /* try to load embedded bitmap (if any) */
    if ( size->strike_index != 0xFFFFFFFFUL      &&
         ( load_flags & FT_LOAD_NO_BITMAP ) == 0 &&
         IS_DEFAULT_INSTANCE                     )
    {
      error = load_sbit_image( size, glyph, glyph_index, load_flags );
      if ( FT_ERR_EQ( error, Missing_Bitmap ) )
      {
        /* the bitmap strike is incomplete and misses the requested glyph; */
        /* if we have a bitmap-only font, return an empty glyph            */
        if ( !FT_IS_SCALABLE( glyph->face ) )
        {
          TT_Face    face = (TT_Face)glyph->face;
          FT_Short   left_bearing = 0, top_bearing = 0;
          FT_UShort  advance_width = 0, advance_height = 0;


          /* to return an empty glyph, however, we need metrics data   */
          /* from the `hmtx' (or `vmtx') table; the assumption is that */
          /* empty glyphs are missing intentionally, representing      */
          /* whitespace - not having at least horizontal metrics is    */
          /* thus considered an error                                  */
          if ( !face->horz_metrics_size )
            return error;

          /* we now construct an empty bitmap glyph */
          TT_Get_HMetrics( face, glyph_index,
                           &left_bearing,
                           &advance_width );
          TT_Get_VMetrics( face, glyph_index,
                           0,
                           &top_bearing,
                           &advance_height );

          glyph->outline.n_points   = 0;
          glyph->outline.n_contours = 0;

          glyph->metrics.width  = 0;
          glyph->metrics.height = 0;

          glyph->metrics.horiBearingX = left_bearing;
          glyph->metrics.horiBearingY = 0;
          glyph->metrics.horiAdvance  = advance_width;

          glyph->metrics.vertBearingX = 0;
          glyph->metrics.vertBearingY = top_bearing;
          glyph->metrics.vertAdvance  = advance_height;

          glyph->format            = FT_GLYPH_FORMAT_BITMAP;
          glyph->bitmap.pixel_mode = FT_PIXEL_MODE_MONO;

          glyph->bitmap_left = 0;
          glyph->bitmap_top  = 0;

          return FT_Err_Ok;
        }
      }
      else if ( error )
      {
        /* return error if font is not scalable */
        if ( !FT_IS_SCALABLE( glyph->face ) )
          return error;
      }
      else
      {
        if ( FT_IS_SCALABLE( glyph->face ) )
        {
          /* for the bbox we need the header only */
          (void)tt_loader_init( &loader, size, glyph, load_flags, TRUE );
          (void)load_truetype_glyph( &loader, glyph_index, 0, TRUE );
          tt_loader_done( &loader );
          glyph->linearHoriAdvance = loader.linear;
          glyph->linearVertAdvance = loader.vadvance;

          /* sanity checks: if `xxxAdvance' in the sbit metric */
          /* structure isn't set, use `linearXXXAdvance'      */
          if ( !glyph->metrics.horiAdvance && glyph->linearHoriAdvance )
            glyph->metrics.horiAdvance =
              FT_MulFix( glyph->linearHoriAdvance,
                         size->metrics->x_scale );
          if ( !glyph->metrics.vertAdvance && glyph->linearVertAdvance )
            glyph->metrics.vertAdvance =
              FT_MulFix( glyph->linearVertAdvance,
                         size->metrics->y_scale );
        }

        return FT_Err_Ok;
      }
    }

#endif /* TT_CONFIG_OPTION_EMBEDDED_BITMAPS */

    /* if FT_LOAD_NO_SCALE is not set, `ttmetrics' must be valid */
    if ( !( load_flags & FT_LOAD_NO_SCALE ) && !size->ttmetrics.valid )
    {
      error = FT_THROW( Invalid_Size_Handle );
      goto Exit;
    }

    if ( load_flags & FT_LOAD_SBITS_ONLY )
    {
      error = FT_THROW( Invalid_Argument );
      goto Exit;
    }

    error = tt_loader_init( &loader, size, glyph, load_flags, FALSE );
    if ( error )
      goto Exit;

    glyph->format        = FT_GLYPH_FORMAT_OUTLINE;
    glyph->num_subglyphs = 0;
    glyph->outline.flags = 0;

    /* main loading loop */
    error = load_truetype_glyph( &loader, glyph_index, 0, FALSE );
    if ( !error )
    {
      if ( glyph->format == FT_GLYPH_FORMAT_COMPOSITE )
      {
        glyph->num_subglyphs = loader.gloader->base.num_subglyphs;
        glyph->subglyphs     = loader.gloader->base.subglyphs;
      }
      else
      {
        glyph->outline        = loader.gloader->base.outline;
        glyph->outline.flags &= ~FT_OUTLINE_SINGLE_PASS;

        /* Translate array so that (0,0) is the glyph's origin.  Note  */
        /* that this behaviour is independent on the value of bit 1 of */
        /* the `flags' field in the `head' table -- at least major     */
        /* applications like Acroread indicate that.                   */
        if ( loader.pp1.x )
          FT_Outline_Translate( &glyph->outline, -loader.pp1.x, 0 );
      }

#ifdef TT_USE_BYTECODE_INTERPRETER

      if ( IS_HINTED( load_flags ) )
      {
        if ( loader.exec->GS.scan_control )
        {
          /* convert scan conversion mode to FT_OUTLINE_XXX flags */
          switch ( loader.exec->GS.scan_type )
          {
          case 0: /* simple drop-outs including stubs */
            glyph->outline.flags |= FT_OUTLINE_INCLUDE_STUBS;
            break;
          case 1: /* simple drop-outs excluding stubs */
            /* nothing; it's the default rendering mode */
            break;
          case 4: /* smart drop-outs including stubs */
            glyph->outline.flags |= FT_OUTLINE_SMART_DROPOUTS |
                                    FT_OUTLINE_INCLUDE_STUBS;
            break;
          case 5: /* smart drop-outs excluding stubs  */
            glyph->outline.flags |= FT_OUTLINE_SMART_DROPOUTS;
            break;

          default: /* no drop-out control */
            glyph->outline.flags |= FT_OUTLINE_IGNORE_DROPOUTS;
            break;
          }
        }
        else
          glyph->outline.flags |= FT_OUTLINE_IGNORE_DROPOUTS;
      }

#endif /* TT_USE_BYTECODE_INTERPRETER */

      error = compute_glyph_metrics( &loader, glyph_index );
    }

    tt_loader_done( &loader );

    /* Set the `high precision' bit flag.                           */
    /* This is _critical_ to get correct output for monochrome      */
    /* TrueType glyphs at all sizes using the bytecode interpreter. */
    /*                                                              */
    if ( !( load_flags & FT_LOAD_NO_SCALE ) &&
         size->metrics->y_ppem < 24         )
      glyph->outline.flags |= FT_OUTLINE_HIGH_PRECISION;

  Exit:
#ifdef FT_DEBUG_LEVEL_TRACE
    if ( error )
      FT_TRACE1(( "  failed (error code 0x%x)\n",
                  error ));
#endif

    return error;
  }

Referenced by tt_glyph_load().