misc/libfreetype/src/pfr/pfrsbit.c
changeset 5172 88f2e05288ba
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/misc/libfreetype/src/pfr/pfrsbit.c	Mon Apr 25 01:46:54 2011 +0200
@@ -0,0 +1,698 @@
+/***************************************************************************/
+/*                                                                         */
+/*  pfrsbit.c                                                              */
+/*                                                                         */
+/*    FreeType PFR bitmap loader (body).                                   */
+/*                                                                         */
+/*  Copyright 2002, 2003, 2006, 2009, 2010 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 "pfrsbit.h"
+#include "pfrload.h"
+#include FT_INTERNAL_DEBUG_H
+#include FT_INTERNAL_STREAM_H
+
+#include "pfrerror.h"
+
+#undef  FT_COMPONENT
+#define FT_COMPONENT  trace_pfr
+
+
+  /*************************************************************************/
+  /*************************************************************************/
+  /*****                                                               *****/
+  /*****                      PFR BIT WRITER                           *****/
+  /*****                                                               *****/
+  /*************************************************************************/
+  /*************************************************************************/
+
+  typedef struct  PFR_BitWriter_
+  {
+    FT_Byte*  line;      /* current line start                    */
+    FT_Int    pitch;     /* line size in bytes                    */
+    FT_Int    width;     /* width in pixels/bits                  */
+    FT_Int    rows;      /* number of remaining rows to scan      */
+    FT_Int    total;     /* total number of bits to draw          */
+
+  } PFR_BitWriterRec, *PFR_BitWriter;
+
+
+  static void
+  pfr_bitwriter_init( PFR_BitWriter  writer,
+                      FT_Bitmap*     target,
+                      FT_Bool        decreasing )
+  {
+    writer->line   = target->buffer;
+    writer->pitch  = target->pitch;
+    writer->width  = target->width;
+    writer->rows   = target->rows;
+    writer->total  = writer->width * writer->rows;
+
+    if ( !decreasing )
+    {
+      writer->line += writer->pitch * ( target->rows-1 );
+      writer->pitch = -writer->pitch;
+    }
+  }
+
+
+  static void
+  pfr_bitwriter_decode_bytes( PFR_BitWriter  writer,
+                              FT_Byte*       p,
+                              FT_Byte*       limit )
+  {
+    FT_Int    n, reload;
+    FT_Int    left = writer->width;
+    FT_Byte*  cur  = writer->line;
+    FT_UInt   mask = 0x80;
+    FT_UInt   val  = 0;
+    FT_UInt   c    = 0;
+
+
+    n = (FT_Int)( limit - p ) * 8;
+    if ( n > writer->total )
+      n = writer->total;
+
+    reload = n & 7;
+
+    for ( ; n > 0; n-- )
+    {
+      if ( ( n & 7 ) == reload )
+        val = *p++;
+
+      if ( val & 0x80 )
+        c |= mask;
+
+      val  <<= 1;
+      mask >>= 1;
+
+      if ( --left <= 0 )
+      {
+        cur[0] = (FT_Byte)c;
+        left   = writer->width;
+        mask   = 0x80;
+
+        writer->line += writer->pitch;
+        cur           = writer->line;
+        c             = 0;
+      }
+      else if ( mask == 0 )
+      {
+        cur[0] = (FT_Byte)c;
+        mask   = 0x80;
+        c      = 0;
+        cur ++;
+      }
+    }
+
+    if ( mask != 0x80 )
+      cur[0] = (FT_Byte)c;
+  }
+
+
+  static void
+  pfr_bitwriter_decode_rle1( PFR_BitWriter  writer,
+                             FT_Byte*       p,
+                             FT_Byte*       limit )
+  {
+    FT_Int    n, phase, count, counts[2], reload;
+    FT_Int    left = writer->width;
+    FT_Byte*  cur  = writer->line;
+    FT_UInt   mask = 0x80;
+    FT_UInt   c    = 0;
+
+
+    n = writer->total;
+
+    phase     = 1;
+    counts[0] = 0;
+    counts[1] = 0;
+    count     = 0;
+    reload    = 1;
+
+    for ( ; n > 0; n-- )
+    {
+      if ( reload )
+      {
+        do
+        {
+          if ( phase )
+          {
+            FT_Int  v;
+
+
+            if ( p >= limit )
+              break;
+
+            v         = *p++;
+            counts[0] = v >> 4;
+            counts[1] = v & 15;
+            phase     = 0;
+            count     = counts[0];
+          }
+          else
+          {
+            phase = 1;
+            count = counts[1];
+          }
+
+        } while ( count == 0 );
+      }
+
+      if ( phase )
+        c |= mask;
+
+      mask >>= 1;
+
+      if ( --left <= 0 )
+      {
+        cur[0] = (FT_Byte) c;
+        left   = writer->width;
+        mask   = 0x80;
+
+        writer->line += writer->pitch;
+        cur           = writer->line;
+        c             = 0;
+      }
+      else if ( mask == 0 )
+      {
+        cur[0] = (FT_Byte)c;
+        mask   = 0x80;
+        c      = 0;
+        cur ++;
+      }
+
+      reload = ( --count <= 0 );
+    }
+
+    if ( mask != 0x80 )
+      cur[0] = (FT_Byte) c;
+  }
+
+
+  static void
+  pfr_bitwriter_decode_rle2( PFR_BitWriter  writer,
+                             FT_Byte*       p,
+                             FT_Byte*       limit )
+  {
+    FT_Int    n, phase, count, reload;
+    FT_Int    left = writer->width;
+    FT_Byte*  cur  = writer->line;
+    FT_UInt   mask = 0x80;
+    FT_UInt   c    = 0;
+
+
+    n = writer->total;
+
+    phase  = 1;
+    count  = 0;
+    reload = 1;
+
+    for ( ; n > 0; n-- )
+    {
+      if ( reload )
+      {
+        do
+        {
+          if ( p >= limit )
+            break;
+
+          count = *p++;
+          phase = phase ^ 1;
+
+        } while ( count == 0 );
+      }
+
+      if ( phase )
+        c |= mask;
+
+      mask >>= 1;
+
+      if ( --left <= 0 )
+      {
+        cur[0] = (FT_Byte) c;
+        c      = 0;
+        mask   = 0x80;
+        left   = writer->width;
+
+        writer->line += writer->pitch;
+        cur           = writer->line;
+      }
+      else if ( mask == 0 )
+      {
+        cur[0] = (FT_Byte)c;
+        c      = 0;
+        mask   = 0x80;
+        cur ++;
+      }
+
+      reload = ( --count <= 0 );
+    }
+
+    if ( mask != 0x80 )
+      cur[0] = (FT_Byte) c;
+  }
+
+
+  /*************************************************************************/
+  /*************************************************************************/
+  /*****                                                               *****/
+  /*****                  BITMAP DATA DECODING                         *****/
+  /*****                                                               *****/
+  /*************************************************************************/
+  /*************************************************************************/
+
+  static void
+  pfr_lookup_bitmap_data( FT_Byte*   base,
+                          FT_Byte*   limit,
+                          FT_UInt    count,
+                          FT_UInt    flags,
+                          FT_UInt    char_code,
+                          FT_ULong*  found_offset,
+                          FT_ULong*  found_size )
+  {
+    FT_UInt   left, right, char_len;
+    FT_Bool   two = FT_BOOL( flags & 1 );
+    FT_Byte*  buff;
+
+
+    char_len = 4;
+    if ( two )       char_len += 1;
+    if ( flags & 2 ) char_len += 1;
+    if ( flags & 4 ) char_len += 1;
+
+    left  = 0;
+    right = count;
+
+    while ( left < right )
+    {
+      FT_UInt  middle, code;
+
+
+      middle = ( left + right ) >> 1;
+      buff   = base + middle * char_len;
+
+      /* check that we are not outside of the table -- */
+      /* this is possible with broken fonts...         */
+      if ( buff + char_len > limit )
+        goto Fail;
+
+      if ( two )
+        code = PFR_NEXT_USHORT( buff );
+      else
+        code = PFR_NEXT_BYTE( buff );
+
+      if ( code == char_code )
+        goto Found_It;
+
+      if ( code < char_code )
+        left = middle;
+      else
+        right = middle;
+    }
+
+  Fail:
+    /* Not found */
+    *found_size   = 0;
+    *found_offset = 0;
+    return;
+
+  Found_It:
+    if ( flags & 2 )
+      *found_size = PFR_NEXT_USHORT( buff );
+    else
+      *found_size = PFR_NEXT_BYTE( buff );
+
+    if ( flags & 4 )
+      *found_offset = PFR_NEXT_ULONG( buff );
+    else
+      *found_offset = PFR_NEXT_USHORT( buff );
+  }
+
+
+  /* load bitmap metrics.  "*padvance" must be set to the default value */
+  /* before calling this function...                                    */
+  /*                                                                    */
+  static FT_Error
+  pfr_load_bitmap_metrics( FT_Byte**  pdata,
+                           FT_Byte*   limit,
+                           FT_Long    scaled_advance,
+                           FT_Long   *axpos,
+                           FT_Long   *aypos,
+                           FT_UInt   *axsize,
+                           FT_UInt   *aysize,
+                           FT_Long   *aadvance,
+                           FT_UInt   *aformat )
+  {
+    FT_Error  error = PFR_Err_Ok;
+    FT_Byte   flags;
+    FT_Char   b;
+    FT_Byte*  p = *pdata;
+    FT_Long   xpos, ypos, advance;
+    FT_UInt   xsize, ysize;
+
+
+    PFR_CHECK( 1 );
+    flags = PFR_NEXT_BYTE( p );
+
+    xpos    = 0;
+    ypos    = 0;
+    xsize   = 0;
+    ysize   = 0;
+    advance = 0;
+
+    switch ( flags & 3 )
+    {
+    case 0:
+      PFR_CHECK( 1 );
+      b    = PFR_NEXT_INT8( p );
+      xpos = b >> 4;
+      ypos = ( (FT_Char)( b << 4 ) ) >> 4;
+      break;
+
+    case 1:
+      PFR_CHECK( 2 );
+      xpos = PFR_NEXT_INT8( p );
+      ypos = PFR_NEXT_INT8( p );
+      break;
+
+    case 2:
+      PFR_CHECK( 4 );
+      xpos = PFR_NEXT_SHORT( p );
+      ypos = PFR_NEXT_SHORT( p );
+      break;
+
+    case 3:
+      PFR_CHECK( 6 );
+      xpos = PFR_NEXT_LONG( p );
+      ypos = PFR_NEXT_LONG( p );
+      break;
+
+    default:
+      ;
+    }
+
+    flags >>= 2;
+    switch ( flags & 3 )
+    {
+    case 0:
+      /* blank image */
+      xsize = 0;
+      ysize = 0;
+      break;
+
+    case 1:
+      PFR_CHECK( 1 );
+      b     = PFR_NEXT_BYTE( p );
+      xsize = ( b >> 4 ) & 0xF;
+      ysize = b & 0xF;
+      break;
+
+    case 2:
+      PFR_CHECK( 2 );
+      xsize = PFR_NEXT_BYTE( p );
+      ysize = PFR_NEXT_BYTE( p );
+      break;
+
+    case 3:
+      PFR_CHECK( 4 );
+      xsize = PFR_NEXT_USHORT( p );
+      ysize = PFR_NEXT_USHORT( p );
+      break;
+
+    default:
+      ;
+    }
+
+    flags >>= 2;
+    switch ( flags & 3 )
+    {
+    case 0:
+      advance = scaled_advance;
+      break;
+
+    case 1:
+      PFR_CHECK( 1 );
+      advance = PFR_NEXT_INT8( p ) << 8;
+      break;
+
+    case 2:
+      PFR_CHECK( 2 );
+      advance = PFR_NEXT_SHORT( p );
+      break;
+
+    case 3:
+      PFR_CHECK( 3 );
+      advance = PFR_NEXT_LONG( p );
+      break;
+
+    default:
+      ;
+    }
+
+    *axpos    = xpos;
+    *aypos    = ypos;
+    *axsize   = xsize;
+    *aysize   = ysize;
+    *aadvance = advance;
+    *aformat  = flags >> 2;
+    *pdata    = p;
+
+  Exit:
+    return error;
+
+  Too_Short:
+    error = PFR_Err_Invalid_Table;
+    FT_ERROR(( "pfr_load_bitmap_metrics: invalid glyph data\n" ));
+    goto Exit;
+  }
+
+
+  static FT_Error
+  pfr_load_bitmap_bits( FT_Byte*    p,
+                        FT_Byte*    limit,
+                        FT_UInt     format,
+                        FT_Bool     decreasing,
+                        FT_Bitmap*  target )
+  {
+    FT_Error          error = PFR_Err_Ok;
+    PFR_BitWriterRec  writer;
+
+
+    if ( target->rows > 0 && target->width > 0 )
+    {
+      pfr_bitwriter_init( &writer, target, decreasing );
+
+      switch ( format )
+      {
+      case 0: /* packed bits */
+        pfr_bitwriter_decode_bytes( &writer, p, limit );
+        break;
+
+      case 1: /* RLE1 */
+        pfr_bitwriter_decode_rle1( &writer, p, limit );
+        break;
+
+      case 2: /* RLE2 */
+        pfr_bitwriter_decode_rle2( &writer, p, limit );
+        break;
+
+      default:
+        FT_ERROR(( "pfr_read_bitmap_data: invalid image type\n" ));
+        error = PFR_Err_Invalid_File_Format;
+      }
+    }
+
+    return error;
+  }
+
+
+  /*************************************************************************/
+  /*************************************************************************/
+  /*****                                                               *****/
+  /*****                     BITMAP LOADING                            *****/
+  /*****                                                               *****/
+  /*************************************************************************/
+  /*************************************************************************/
+
+  FT_LOCAL( FT_Error )
+  pfr_slot_load_bitmap( PFR_Slot  glyph,
+                        PFR_Size  size,
+                        FT_UInt   glyph_index )
+  {
+    FT_Error     error;
+    PFR_Face     face   = (PFR_Face) glyph->root.face;
+    FT_Stream    stream = face->root.stream;
+    PFR_PhyFont  phys   = &face->phy_font;
+    FT_ULong     gps_offset;
+    FT_ULong     gps_size;
+    PFR_Char     character;
+    PFR_Strike   strike;
+
+
+    character = &phys->chars[glyph_index];
+
+    /* Look-up a bitmap strike corresponding to the current */
+    /* character dimensions                                 */
+    {
+      FT_UInt  n;
+
+
+      strike = phys->strikes;
+      for ( n = 0; n < phys->num_strikes; n++ )
+      {
+        if ( strike->x_ppm == (FT_UInt)size->root.metrics.x_ppem &&
+             strike->y_ppm == (FT_UInt)size->root.metrics.y_ppem )
+        {
+          goto Found_Strike;
+        }
+
+        strike++;
+      }
+
+      /* couldn't find it */
+      return PFR_Err_Invalid_Argument;
+    }
+
+  Found_Strike:
+
+    /* Now lookup the glyph's position within the file */
+    {
+      FT_UInt  char_len;
+
+
+      char_len = 4;
+      if ( strike->flags & 1 ) char_len += 1;
+      if ( strike->flags & 2 ) char_len += 1;
+      if ( strike->flags & 4 ) char_len += 1;
+
+      /* Access data directly in the frame to speed lookups */
+      if ( FT_STREAM_SEEK( phys->bct_offset + strike->bct_offset ) ||
+           FT_FRAME_ENTER( char_len * strike->num_bitmaps )        )
+        goto Exit;
+
+      pfr_lookup_bitmap_data( stream->cursor,
+                              stream->limit,
+                              strike->num_bitmaps,
+                              strike->flags,
+                              character->char_code,
+                              &gps_offset,
+                              &gps_size );
+
+      FT_FRAME_EXIT();
+
+      if ( gps_size == 0 )
+      {
+        /* Could not find a bitmap program string for this glyph */
+        error = PFR_Err_Invalid_Argument;
+        goto Exit;
+      }
+    }
+
+    /* get the bitmap metrics */
+    {
+      FT_Long   xpos = 0, ypos = 0, advance = 0;
+      FT_UInt   xsize = 0, ysize = 0, format = 0;
+      FT_Byte*  p;
+
+
+      /* compute linear advance */
+      advance = character->advance;
+      if ( phys->metrics_resolution != phys->outline_resolution )
+        advance = FT_MulDiv( advance,
+                             phys->outline_resolution,
+                             phys->metrics_resolution );
+
+      glyph->root.linearHoriAdvance = advance;
+
+      /* compute default advance, i.e., scaled advance.  This can be */
+      /* overridden in the bitmap header of certain glyphs.          */
+      advance = FT_MulDiv( (FT_Fixed)size->root.metrics.x_ppem << 8,
+                           character->advance,
+                           phys->metrics_resolution );
+
+      if ( FT_STREAM_SEEK( face->header.gps_section_offset + gps_offset ) ||
+           FT_FRAME_ENTER( gps_size )                                     )
+        goto Exit;
+
+      p     = stream->cursor;
+      error = pfr_load_bitmap_metrics( &p, stream->limit,
+                                       advance,
+                                       &xpos, &ypos,
+                                       &xsize, &ysize,
+                                       &advance, &format );
+
+      /*
+       * XXX: on 16bit system, we return an error for huge bitmap
+       *      which causes a size truncation, because truncated
+       *      size properties makes bitmap glyph broken.
+       */
+      if ( xpos > FT_INT_MAX || ( ypos + ysize ) > FT_INT_MAX )
+      {
+        FT_TRACE1(( "pfr_slot_load_bitmap:" ));
+        FT_TRACE1(( "huge bitmap glyph %dx%d over FT_GlyphSlot\n",
+                     xpos, ypos ));
+        error = PFR_Err_Invalid_Pixel_Size;
+      }
+
+      if ( !error )
+      {
+        glyph->root.format = FT_GLYPH_FORMAT_BITMAP;
+
+        /* Set up glyph bitmap and metrics */
+
+        /* XXX: needs casts to fit FT_Bitmap.{width|rows|pitch} */
+        glyph->root.bitmap.width      = (FT_Int)xsize;
+        glyph->root.bitmap.rows       = (FT_Int)ysize;
+        glyph->root.bitmap.pitch      = (FT_Int)( xsize + 7 ) >> 3;
+        glyph->root.bitmap.pixel_mode = FT_PIXEL_MODE_MONO;
+
+        /* XXX: needs casts to fit FT_Glyph_Metrics.{width|height} */
+        glyph->root.metrics.width        = (FT_Pos)xsize << 6;
+        glyph->root.metrics.height       = (FT_Pos)ysize << 6;
+        glyph->root.metrics.horiBearingX = xpos << 6;
+        glyph->root.metrics.horiBearingY = ypos << 6;
+        glyph->root.metrics.horiAdvance  = FT_PIX_ROUND( ( advance >> 2 ) );
+        glyph->root.metrics.vertBearingX = - glyph->root.metrics.width >> 1;
+        glyph->root.metrics.vertBearingY = 0;
+        glyph->root.metrics.vertAdvance  = size->root.metrics.height;
+
+        /* XXX: needs casts fit FT_GlyphSlotRec.bitmap_{left|top} */
+        glyph->root.bitmap_left = (FT_Int)xpos;
+        glyph->root.bitmap_top  = (FT_Int)(ypos + ysize);
+
+        /* Allocate and read bitmap data */
+        {
+          FT_ULong  len = glyph->root.bitmap.pitch * ysize;
+
+
+          error = ft_glyphslot_alloc_bitmap( &glyph->root, len );
+          if ( !error )
+          {
+            error = pfr_load_bitmap_bits(
+                      p,
+                      stream->limit,
+                      format,
+                      FT_BOOL(face->header.color_flags & 2),
+                      &glyph->root.bitmap );
+          }
+        }
+      }
+
+      FT_FRAME_EXIT();
+    }
+
+  Exit:
+    return error;
+  }
+
+/* END */