pfrgload.c

winNT技术操作系统,国外开放的原代码和LIUX一样

/***************************************************************************/
/*                                                                         */
/*  pfrgload.c                                                             */
/*                                                                         */
/*    FreeType PFR glyph loader (body).                                    */
/*                                                                         */
/*  Copyright 2002, 2003, 2005 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 "pfrgload.h"
#include "pfrsbit.h"
#include "pfrload.h"            /* for macro definitions */
#include FT_INTERNAL_DEBUG_H

#include "pfrerror.h"

#undef  FT_COMPONENT
#define FT_COMPONENT  trace_pfr


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                      PFR GLYPH BUILDER                        *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/


  FT_LOCAL_DEF( void )
  pfr_glyph_init( PFR_Glyph       glyph,
                  FT_GlyphLoader  loader )
  {
    FT_ZERO( glyph );

    glyph->loader     = loader;
    glyph->path_begun = 0;

    FT_GlyphLoader_Rewind( loader );
  }


  FT_LOCAL_DEF( void )
  pfr_glyph_done( PFR_Glyph  glyph )
  {
    FT_Memory  memory = glyph->loader->memory;


    FT_FREE( glyph->x_control );
    glyph->y_control = NULL;

    glyph->max_xy_control = 0;
    glyph->num_x_control  = 0;
    glyph->num_y_control  = 0;

    FT_FREE( glyph->subs );

    glyph->max_subs = 0;
    glyph->num_subs = 0;

    glyph->loader     = NULL;
    glyph->path_begun = 0;
  }


  /* close current contour, if any */
  static void
  pfr_glyph_close_contour( PFR_Glyph  glyph )
  {
    FT_GlyphLoader  loader  = glyph->loader;
    FT_Outline*     outline = &loader->current.outline;
    FT_Int          last, first;


    if ( !glyph->path_begun )
      return;

    /* compute first and last point indices in current glyph outline */
    last  = outline->n_points - 1;
    first = 0;
    if ( outline->n_contours > 0 )
      first = outline->contours[outline->n_contours - 1];

    /* if the last point falls on the same location than the first one */
    /* we need to delete it                                            */
    if ( last > first )
    {
      FT_Vector*  p1 = outline->points + first;
      FT_Vector*  p2 = outline->points + last;


      if ( p1->x == p2->x && p1->y == p2->y )
      {
        outline->n_points--;
        last--;
      }
    }

    /* don't add empty contours */
    if ( last >= first )
      outline->contours[outline->n_contours++] = (short)last;

    glyph->path_begun = 0;
  }


  /* reset glyph to start the loading of a new glyph */
  static void
  pfr_glyph_start( PFR_Glyph  glyph )
  {
    glyph->path_begun = 0;
  }


  static FT_Error
  pfr_glyph_line_to( PFR_Glyph   glyph,
                     FT_Vector*  to )
  {
    FT_GlyphLoader  loader  = glyph->loader;
    FT_Outline*     outline = &loader->current.outline;
    FT_Error        error;


    /* check that we have begun a new path */
    FT_ASSERT( glyph->path_begun != 0 );

    error = FT_GLYPHLOADER_CHECK_POINTS( loader, 1, 0 );
    if ( !error )
    {
      FT_UInt  n = outline->n_points;


      outline->points[n] = *to;
      outline->tags  [n] = FT_CURVE_TAG_ON;

      outline->n_points++;
    }

    return error;
  }


  static FT_Error
  pfr_glyph_curve_to( PFR_Glyph   glyph,
                      FT_Vector*  control1,
                      FT_Vector*  control2,
                      FT_Vector*  to )
  {
    FT_GlyphLoader  loader  = glyph->loader;
    FT_Outline*     outline = &loader->current.outline;
    FT_Error        error;


    /* check that we have begun a new path */
    FT_ASSERT( glyph->path_begun != 0 );

    error = FT_GLYPHLOADER_CHECK_POINTS( loader, 3, 0 );
    if ( !error )
    {
      FT_Vector*  vec = outline->points         + outline->n_points;
      FT_Byte*    tag = (FT_Byte*)outline->tags + outline->n_points;


      vec[0] = *control1;
      vec[1] = *control2;
      vec[2] = *to;
      tag[0] = FT_CURVE_TAG_CUBIC;
      tag[1] = FT_CURVE_TAG_CUBIC;
      tag[2] = FT_CURVE_TAG_ON;

      outline->n_points = (FT_Short)( outline->n_points + 3 );
    }

    return error;
  }


  static FT_Error
  pfr_glyph_move_to( PFR_Glyph   glyph,
                     FT_Vector*  to )
  {
    FT_GlyphLoader  loader  = glyph->loader;
    FT_Error        error;


    /* close current contour if any */
    pfr_glyph_close_contour( glyph );

    /* indicate that a new contour has started */
    glyph->path_begun = 1;

    /* check that there is space for a new contour and a new point */
    error = FT_GLYPHLOADER_CHECK_POINTS( loader, 1, 1 );
    if ( !error )
      /* add new start point */
      error = pfr_glyph_line_to( glyph, to );

    return error;
  }


  static void
  pfr_glyph_end( PFR_Glyph  glyph )
  {
    /* close current contour if any */
    pfr_glyph_close_contour( glyph );

    /* merge the current glyph into the stack */
    FT_GlyphLoader_Add( glyph->loader );
  }


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                      PFR GLYPH LOADER                         *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/


  /* load a simple glyph */
  static FT_Error
  pfr_glyph_load_simple( PFR_Glyph  glyph,
                         FT_Byte*   p,
                         FT_Byte*   limit )
  {
    FT_Error   error  = 0;
    FT_Memory  memory = glyph->loader->memory;
    FT_UInt    flags, x_count, y_count, i, count, mask;
    FT_Int     x;


    PFR_CHECK( 1 );
    flags = PFR_NEXT_BYTE( p );

    /* test for composite glyphs */
    FT_ASSERT( ( flags & PFR_GLYPH_IS_COMPOUND ) == 0 );

    x_count = 0;
    y_count = 0;

    if ( flags & PFR_GLYPH_1BYTE_XYCOUNT )
    {
      PFR_CHECK( 1 );
      count   = PFR_NEXT_BYTE( p );
      x_count = ( count & 15 );
      y_count = ( count >> 4 );
    }
    else
    {
      if ( flags & PFR_GLYPH_XCOUNT )
      {
        PFR_CHECK( 1 );
        x_count = PFR_NEXT_BYTE( p );
      }

      if ( flags & PFR_GLYPH_YCOUNT )
      {
        PFR_CHECK( 1 );
        y_count = PFR_NEXT_BYTE( p );
      }
    }

    count = x_count + y_count;

    /* re-allocate array when necessary */
    if ( count > glyph->max_xy_control )
    {
      FT_UInt  new_max = FT_PAD_CEIL( count, 8 );


      if ( FT_RENEW_ARRAY( glyph->x_control,
                           glyph->max_xy_control,
                           new_max ) )
        goto Exit;

      glyph->max_xy_control = new_max;
    }

    glyph->y_control = glyph->x_control + x_count;

    mask  = 0;
    x     = 0;

    for ( i = 0; i < count; i++ )
    {
      if ( ( i & 7 ) == 0 )
      {
        PFR_CHECK( 1 );
        mask = PFR_NEXT_BYTE( p );
      }

      if ( mask & 1 )
      {
        PFR_CHECK( 2 );
        x = PFR_NEXT_SHORT( p );
      }
      else
      {
        PFR_CHECK( 1 );
        x += PFR_NEXT_BYTE( p );
      }

      glyph->x_control[i] = x;

      mask >>= 1;
    }

    /* XXX: for now we ignore the secondary stroke and edge definitions */
    /*      since we don't want to support native PFR hinting           */
    /*                                                                  */
    if ( flags & PFR_GLYPH_EXTRA_ITEMS )
    {
      error = pfr_extra_items_skip( &p, limit );
      if ( error )
        goto Exit;
    }

    pfr_glyph_start( glyph );

    /* now load a simple glyph */
    {
      FT_Vector   pos[4];
      FT_Vector*  cur;


      pos[0].x = pos[0].y = 0;
      pos[3]   = pos[0];

      for (;;)
      {
        FT_Int  format, args_format = 0, args_count, n;


        /***************************************************************/
        /*  read instruction                                           */
        /*                                                             */
        PFR_CHECK( 1 );
        format = PFR_NEXT_BYTE( p );

        switch ( format >> 4 )
        {
        case 0:                             /* end glyph */
          FT_TRACE6(( "- end glyph" ));
          args_count = 0;
          break;

        case 1:                             /* general line operation */
          FT_TRACE6(( "- general line" ));
          goto Line1;

        case 4:                             /* move to inside contour  */
          FT_TRACE6(( "- move to inside" ));
          goto Line1;

        case 5:                             /* move to outside contour */
          FT_TRACE6(( "- move to outside" ));
        Line1:
          args_format = format & 15;
          args_count  = 1;
          break;

        case 2:                             /* horizontal line to */
          FT_TRACE6(( "- horizontal line to cx.%d", format & 15 ));
          pos[0].y   = pos[3].y;
          pos[0].x   = glyph->x_control[format & 15];
          pos[3]     = pos[0];
          args_count = 0;
          break;

        case 3:                             /* vertical line to */
          FT_TRACE6(( "- vertical line to cy.%d", format & 15 ));
          pos[0].x   = pos[3].x;
          pos[0].y   = glyph->y_control[format & 15];
          pos[3] = pos[0];
          args_count = 0;
          break;

        case 6:                             /* horizontal to vertical curve */
          FT_TRACE6(( "- hv curve " ));
          args_format  = 0xB8E;
          args_count   = 3;
          break;

        case 7:                             /* vertical to horizontal curve */
          FT_TRACE6(( "- vh curve" ));
          args_format = 0xE2B;
          args_count  = 3;
          break;

        default:                            /* general curve to */
          FT_TRACE6(( "- general curve" ));