misc/libfreetype/src/sfnt/ttmtx.c
changeset 5172 88f2e05288ba
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/misc/libfreetype/src/sfnt/ttmtx.c	Mon Apr 25 01:46:54 2011 +0200
@@ -0,0 +1,468 @@
+/***************************************************************************/
+/*                                                                         */
+/*  ttmtx.c                                                                */
+/*                                                                         */
+/*    Load the metrics tables common to TTF and OTF fonts (body).          */
+/*                                                                         */
+/*  Copyright 2006-2009, 2011 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.                                        */
+/*                                                                         */
+/***************************************************************************/
+
+
+#include <ft2build.h>
+#include FT_INTERNAL_DEBUG_H
+#include FT_INTERNAL_STREAM_H
+#include FT_TRUETYPE_TAGS_H
+#include "ttmtx.h"
+
+#include "sferrors.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_ttmtx
+
+
+  /*
+   *  Unfortunately, we can't enable our memory optimizations if
+   *  FT_CONFIG_OPTION_OLD_INTERNALS is defined.  This is because at least
+   *  one rogue client (libXfont in the X.Org XServer) is directly accessing
+   *  the metrics.
+   */
+
+  /*************************************************************************/
+  /*                                                                       */
+  /* <Function>                                                            */
+  /*    tt_face_load_hmtx                                                  */
+  /*                                                                       */
+  /* <Description>                                                         */
+  /*    Load the `hmtx' or `vmtx' table into a face object.                */
+  /*                                                                       */
+  /* <Input>                                                               */
+  /*    face     :: A handle to the target face object.                    */
+  /*                                                                       */
+  /*    stream   :: The input stream.                                      */
+  /*                                                                       */
+  /*    vertical :: A boolean flag.  If set, load `vmtx'.                  */
+  /*                                                                       */
+  /* <Return>                                                              */
+  /*    FreeType error code.  0 means success.                             */
+  /*                                                                       */
+#ifndef FT_CONFIG_OPTION_OLD_INTERNALS
+
+  FT_LOCAL_DEF( FT_Error )
+  tt_face_load_hmtx( TT_Face    face,
+                     FT_Stream  stream,
+                     FT_Bool    vertical )
+  {
+    FT_Error   error;
+    FT_ULong   tag, table_size;
+    FT_ULong*  ptable_offset;
+    FT_ULong*  ptable_size;
+
+
+    if ( vertical )
+    {
+      tag           = TTAG_vmtx;
+      ptable_offset = &face->vert_metrics_offset;
+      ptable_size   = &face->vert_metrics_size;
+    }
+    else
+    {
+      tag           = TTAG_hmtx;
+      ptable_offset = &face->horz_metrics_offset;
+      ptable_size   = &face->horz_metrics_size;
+    }
+
+    error = face->goto_table( face, tag, stream, &table_size );
+    if ( error )
+      goto Fail;
+
+    *ptable_size   = table_size;
+    *ptable_offset = FT_STREAM_POS();
+
+  Fail:
+    return error;
+  }
+
+#else /* !FT_CONFIG_OPTION_OLD_INTERNALS */
+
+  FT_LOCAL_DEF( FT_Error )
+  tt_face_load_hmtx( TT_Face    face,
+                     FT_Stream  stream,
+                     FT_Bool    vertical )
+  {
+    FT_Error   error;
+    FT_Memory  memory = stream->memory;
+
+    FT_ULong   table_len;
+    FT_Long    num_shorts, num_longs, num_shorts_checked;
+
+    TT_LongMetrics*    longs;
+    TT_ShortMetrics**  shorts;
+    FT_Byte*           p;
+
+
+    if ( vertical )
+    {
+      void*   lm = &face->vertical.long_metrics;
+      void**  sm = &face->vertical.short_metrics;
+
+
+      error = face->goto_table( face, TTAG_vmtx, stream, &table_len );
+      if ( error )
+        goto Fail;
+
+      num_longs = face->vertical.number_Of_VMetrics;
+      if ( (FT_ULong)num_longs > table_len / 4 )
+        num_longs = (FT_Long)( table_len / 4 );
+
+      face->vertical.number_Of_VMetrics = 0;
+
+      longs  = (TT_LongMetrics*)lm;
+      shorts = (TT_ShortMetrics**)sm;
+    }
+    else
+    {
+      void*   lm = &face->horizontal.long_metrics;
+      void**  sm = &face->horizontal.short_metrics;
+
+
+      error = face->goto_table( face, TTAG_hmtx, stream, &table_len );
+      if ( error )
+        goto Fail;
+
+      num_longs = face->horizontal.number_Of_HMetrics;
+      if ( (FT_ULong)num_longs > table_len / 4 )
+        num_longs = (FT_Long)( table_len / 4 );
+
+      face->horizontal.number_Of_HMetrics = 0;
+
+      longs  = (TT_LongMetrics*)lm;
+      shorts = (TT_ShortMetrics**)sm;
+    }
+
+    /* never trust derived values */
+
+    num_shorts         = face->max_profile.numGlyphs - num_longs;
+    num_shorts_checked = ( table_len - num_longs * 4L ) / 2;
+
+    if ( num_shorts < 0 )
+    {
+      FT_TRACE0(( "tt_face_load_hmtx:"
+                  " %cmtx has more metrics than glyphs.\n",
+                  vertical ? 'v' : 'h' ));
+
+      /* Adobe simply ignores this problem.  So we shall do the same. */
+#if 0
+      error = vertical ? SFNT_Err_Invalid_Vert_Metrics
+                       : SFNT_Err_Invalid_Horiz_Metrics;
+      goto Exit;
+#else
+      num_shorts = 0;
+#endif
+    }
+
+    if ( FT_QNEW_ARRAY( *longs,  num_longs  ) ||
+         FT_QNEW_ARRAY( *shorts, num_shorts ) )
+      goto Fail;
+
+    if ( FT_FRAME_ENTER( table_len ) )
+      goto Fail;
+
+    p = stream->cursor;
+
+    {
+      TT_LongMetrics  cur   = *longs;
+      TT_LongMetrics  limit = cur + num_longs;
+
+
+      for ( ; cur < limit; cur++ )
+      {
+        cur->advance = FT_NEXT_USHORT( p );
+        cur->bearing = FT_NEXT_SHORT( p );
+      }
+    }
+
+    /* do we have an inconsistent number of metric values? */
+    {
+      TT_ShortMetrics*  cur   = *shorts;
+      TT_ShortMetrics*  limit = cur +
+                                FT_MIN( num_shorts, num_shorts_checked );
+
+
+      for ( ; cur < limit; cur++ )
+        *cur = FT_NEXT_SHORT( p );
+
+      /* We fill up the missing left side bearings with the     */
+      /* last valid value.  Since this will occur for buggy CJK */
+      /* fonts usually only, nothing serious will happen.       */
+      if ( num_shorts > num_shorts_checked && num_shorts_checked > 0 )
+      {
+        FT_Short  val = (*shorts)[num_shorts_checked - 1];
+
+
+        limit = *shorts + num_shorts;
+        for ( ; cur < limit; cur++ )
+          *cur = val;
+      }
+    }
+
+    FT_FRAME_EXIT();
+
+    if ( vertical )
+      face->vertical.number_Of_VMetrics = (FT_UShort)num_longs;
+    else
+      face->horizontal.number_Of_HMetrics = (FT_UShort)num_longs;
+
+  Fail:
+    return error;
+  }
+
+#endif /* !FT_CONFIG_OPTION_OLD_INTERNALS */
+
+
+  /*************************************************************************/
+  /*                                                                       */
+  /* <Function>                                                            */
+  /*    tt_face_load_hhea                                                  */
+  /*                                                                       */
+  /* <Description>                                                         */
+  /*    Load the `hhea' or 'vhea' table into a face object.                */
+  /*                                                                       */
+  /* <Input>                                                               */
+  /*    face     :: A handle to the target face object.                    */
+  /*                                                                       */
+  /*    stream   :: The input stream.                                      */
+  /*                                                                       */
+  /*    vertical :: A boolean flag.  If set, load `vhea'.                  */
+  /*                                                                       */
+  /* <Return>                                                              */
+  /*    FreeType error code.  0 means success.                             */
+  /*                                                                       */
+  FT_LOCAL_DEF( FT_Error )
+  tt_face_load_hhea( TT_Face    face,
+                     FT_Stream  stream,
+                     FT_Bool    vertical )
+  {
+    FT_Error        error;
+    TT_HoriHeader*  header;
+
+    const FT_Frame_Field  metrics_header_fields[] =
+    {
+#undef  FT_STRUCTURE
+#define FT_STRUCTURE  TT_HoriHeader
+
+      FT_FRAME_START( 36 ),
+        FT_FRAME_ULONG ( Version ),
+        FT_FRAME_SHORT ( Ascender ),
+        FT_FRAME_SHORT ( Descender ),
+        FT_FRAME_SHORT ( Line_Gap ),
+        FT_FRAME_USHORT( advance_Width_Max ),
+        FT_FRAME_SHORT ( min_Left_Side_Bearing ),
+        FT_FRAME_SHORT ( min_Right_Side_Bearing ),
+        FT_FRAME_SHORT ( xMax_Extent ),
+        FT_FRAME_SHORT ( caret_Slope_Rise ),
+        FT_FRAME_SHORT ( caret_Slope_Run ),
+        FT_FRAME_SHORT ( caret_Offset ),
+        FT_FRAME_SHORT ( Reserved[0] ),
+        FT_FRAME_SHORT ( Reserved[1] ),
+        FT_FRAME_SHORT ( Reserved[2] ),
+        FT_FRAME_SHORT ( Reserved[3] ),
+        FT_FRAME_SHORT ( metric_Data_Format ),
+        FT_FRAME_USHORT( number_Of_HMetrics ),
+      FT_FRAME_END
+    };
+
+
+    if ( vertical )
+    {
+      void  *v = &face->vertical;
+
+
+      error = face->goto_table( face, TTAG_vhea, stream, 0 );
+      if ( error )
+        goto Fail;
+
+      header = (TT_HoriHeader*)v;
+    }
+    else
+    {
+      error = face->goto_table( face, TTAG_hhea, stream, 0 );
+      if ( error )
+        goto Fail;
+
+      header = &face->horizontal;
+    }
+
+    if ( FT_STREAM_READ_FIELDS( metrics_header_fields, header ) )
+      goto Fail;
+
+    FT_TRACE3(( "Ascender:          %5d\n", header->Ascender ));
+    FT_TRACE3(( "Descender:         %5d\n", header->Descender ));
+    FT_TRACE3(( "number_Of_Metrics: %5u\n", header->number_Of_HMetrics ));
+
+    header->long_metrics  = NULL;
+    header->short_metrics = NULL;
+
+  Fail:
+    return error;
+  }
+
+
+  /*************************************************************************/
+  /*                                                                       */
+  /* <Function>                                                            */
+  /*    tt_face_get_metrics                                                */
+  /*                                                                       */
+  /* <Description>                                                         */
+  /*    Returns the horizontal or vertical metrics in font units for a     */
+  /*    given glyph.  The metrics are the left side bearing (resp. top     */
+  /*    side bearing) and advance width (resp. advance height).            */
+  /*                                                                       */
+  /* <Input>                                                               */
+  /*    header  :: A pointer to either the horizontal or vertical metrics  */
+  /*               structure.                                              */
+  /*                                                                       */
+  /*    idx     :: The glyph index.                                        */
+  /*                                                                       */
+  /* <Output>                                                              */
+  /*    bearing :: The bearing, either left side or top side.              */
+  /*                                                                       */
+  /*    advance :: The advance width resp. advance height.                 */
+  /*                                                                       */
+#ifndef FT_CONFIG_OPTION_OLD_INTERNALS
+
+  FT_LOCAL_DEF( FT_Error )
+  tt_face_get_metrics( TT_Face     face,
+                       FT_Bool     vertical,
+                       FT_UInt     gindex,
+                       FT_Short   *abearing,
+                       FT_UShort  *aadvance )
+  {
+    FT_Error        error;
+    FT_Stream       stream = face->root.stream;
+    TT_HoriHeader*  header;
+    FT_ULong        table_pos, table_size, table_end;
+    FT_UShort       k;
+
+
+    if ( vertical )
+    {
+      void*  v = &face->vertical;
+
+
+      header     = (TT_HoriHeader*)v;
+      table_pos  = face->vert_metrics_offset;
+      table_size = face->vert_metrics_size;
+    }
+    else
+    {
+      header     = &face->horizontal;
+      table_pos  = face->horz_metrics_offset;
+      table_size = face->horz_metrics_size;
+    }
+
+    table_end = table_pos + table_size;
+
+    k = header->number_Of_HMetrics;
+
+    if ( k > 0 )
+    {
+      if ( gindex < (FT_UInt)k )
+      {
+        table_pos += 4 * gindex;
+        if ( table_pos + 4 > table_end )
+          goto NoData;
+
+        if ( FT_STREAM_SEEK( table_pos ) ||
+             FT_READ_USHORT( *aadvance ) ||
+             FT_READ_SHORT( *abearing )  )
+          goto NoData;
+      }
+      else
+      {
+        table_pos += 4 * ( k - 1 );
+        if ( table_pos + 4 > table_end )
+          goto NoData;
+
+        if ( FT_STREAM_SEEK( table_pos ) ||
+             FT_READ_USHORT( *aadvance ) )
+          goto NoData;
+
+        table_pos += 4 + 2 * ( gindex - k );
+        if ( table_pos + 2 > table_end )
+          *abearing = 0;
+        else
+        {
+          if ( !FT_STREAM_SEEK( table_pos ) )
+            (void)FT_READ_SHORT( *abearing );
+        }
+      }
+    }
+    else
+    {
+    NoData:
+      *abearing = 0;
+      *aadvance = 0;
+    }
+
+    return SFNT_Err_Ok;
+  }
+
+#else /* !FT_CONFIG_OPTION_OLD_INTERNALS */
+
+  FT_LOCAL_DEF( FT_Error )
+  tt_face_get_metrics( TT_Face     face,
+                       FT_Bool     vertical,
+                       FT_UInt     gindex,
+                       FT_Short*   abearing,
+                       FT_UShort*  aadvance )
+  {
+    void*           v = &face->vertical;
+    void*           h = &face->horizontal;
+    TT_HoriHeader*  header = vertical ? (TT_HoriHeader*)v
+                                      : (TT_HoriHeader*)h;
+    TT_LongMetrics  longs_m;
+    FT_UShort       k = header->number_Of_HMetrics;
+
+
+    if ( k == 0                                         ||
+         !header->long_metrics                          ||
+         gindex >= (FT_UInt)face->max_profile.numGlyphs )
+    {
+      *abearing = *aadvance = 0;
+      return SFNT_Err_Ok;
+    }
+
+    if ( gindex < (FT_UInt)k )
+    {
+      longs_m   = (TT_LongMetrics)header->long_metrics + gindex;
+      *abearing = longs_m->bearing;
+      *aadvance = longs_m->advance;
+    }
+    else
+    {
+      *abearing = ((TT_ShortMetrics*)header->short_metrics)[gindex - k];
+      *aadvance = ((TT_LongMetrics)header->long_metrics)[k - 1].advance;
+    }
+
+    return SFNT_Err_Ok;
+  }
+
+#endif /* !FT_CONFIG_OPTION_OLD_INTERNALS */
+
+
+/* END */