ref: e9c50fa77de58b749b4b95706f7b55bfff0dd27f
dir: /src/pfr/pfrsbit.c/
/****************************************************************************
*
* pfrsbit.c
*
* FreeType PFR bitmap loader (body).
*
* Copyright (C) 2002-2021 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 <freetype/internal/ftdebug.h>
#include <freetype/internal/ftstream.h>
#include "pfrerror.h"
#undef FT_COMPONENT
#define FT_COMPONENT pfr
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** PFR BIT WRITER *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
typedef struct PFR_BitWriter_
{
FT_Byte* line; /* current line start */
FT_Int pitch; /* line size in bytes */
FT_UInt width; /* width in pixels/bits */
FT_UInt rows; /* number of remaining rows to scan */
FT_UInt 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 * (FT_Int)( target->rows - 1 );
writer->pitch = -writer->pitch;
}
}
static void
pfr_bitwriter_decode_bytes( PFR_BitWriter writer,
FT_Byte* p,
FT_Byte* limit )
{
FT_UInt n, reload;
FT_UInt left = writer->width;
FT_Byte* cur = writer->line;
FT_UInt mask = 0x80;
FT_UInt val = 0;
FT_UInt c = 0;
n = (FT_UInt)( 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 phase, count, counts[2];
FT_UInt n, reload;
FT_UInt 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 phase, count;
FT_UInt n, reload;
FT_UInt 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 min, max, char_len;
FT_Bool two = FT_BOOL( *flags & PFR_BITMAP_2BYTE_CHARCODE );
FT_Byte* buff;
char_len = 4;
if ( two )
char_len += 1;
if ( *flags & PFR_BITMAP_2BYTE_SIZE )
char_len += 1;
if ( *flags & PFR_BITMAP_3BYTE_OFFSET )
char_len += 1;
if ( !( *flags & PFR_BITMAP_CHARCODES_VALIDATED ) )
{
FT_Byte* p;
FT_Byte* lim;
FT_UInt code;
FT_Long prev_code;
*flags |= PFR_BITMAP_VALID_CHARCODES;
prev_code = -1;
lim = base + count * char_len;
if ( lim > limit )
{
FT_TRACE0(( "pfr_lookup_bitmap_data:"
" number of bitmap records too large,\n" ));
FT_TRACE0(( " "
" thus ignoring all bitmaps in this strike\n" ));
*flags &= ~PFR_BITMAP_VALID_CHARCODES;
}
else
{
/* check whether records are sorted by code */
for ( p = base; p < lim; p += char_len )
{
if ( two )
code = FT_PEEK_USHORT( p );
else
code = *p;
if ( (FT_Long)code <= prev_code )
{
FT_TRACE0(( "pfr_lookup_bitmap_data:"
" bitmap records are not sorted,\n" ));
FT_TRACE0(( " "
" thus ignoring all bitmaps in this strike\n" ));
*flags &= ~PFR_BITMAP_VALID_CHARCODES;
break;
}
prev_code = code;
}
}
*flags |= PFR_BITMAP_CHARCODES_VALIDATED;
}
/* ignore bitmaps in case table is not valid */
/* (this might be sanitized, but PFR is dead...) */
if ( !( *flags & PFR_BITMAP_VALID_CHARCODES ) )
goto Fail;
min = 0;
max = count;
/* binary search */
while ( min < max )
{
FT_UInt mid, code;
mid = ( min + max ) >> 1;
buff = base + mid * char_len;
if ( two )
code = PFR_NEXT_USHORT( buff );
else
code = PFR_NEXT_BYTE( buff );
if ( char_code < code )
max = mid;
else if ( char_code > code )
min = mid + 1;
else
goto Found_It;
}
Fail:
/* Not found */
*found_size = 0;
*found_offset = 0;
return;
Found_It:
if ( *flags & PFR_BITMAP_2BYTE_SIZE )
*found_size = PFR_NEXT_USHORT( buff );
else
*found_size = PFR_NEXT_BYTE( buff );
if ( *flags & PFR_BITMAP_3BYTE_OFFSET )
*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 = FT_Err_Ok;
FT_Byte flags;
FT_Byte 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_BYTE( p );
xpos = (FT_Char)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 ) * 256;
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 = FT_THROW( 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 = FT_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:
;
}
}
return error;
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** BITMAP LOADING *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
FT_LOCAL( FT_Error )
pfr_slot_load_bitmap( PFR_Slot glyph,
PFR_Size size,
FT_UInt glyph_index,
FT_Bool metrics_only )
{
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 FT_THROW( Invalid_Argument );
}
Found_Strike:
/* now look up the glyph's position within the file */
{
FT_UInt char_len;
char_len = 4;
if ( strike->flags & PFR_BITMAP_2BYTE_CHARCODE )
char_len += 1;
if ( strike->flags & PFR_BITMAP_2BYTE_SIZE )
char_len += 1;
if ( strike->flags & PFR_BITMAP_3BYTE_OFFSET )
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 = FT_THROW( 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,
(FT_Long)phys->outline_resolution,
(FT_Long)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,
(FT_Long)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 );
if ( error )
goto Exit1;
/*
* Before allocating the target bitmap, we check whether the given
* bitmap dimensions are valid, depending on the image format.
*
* Format 0: We have a stream of pixels (with 8 pixels per byte).
*
* (xsize * ysize + 7) / 8 <= gps_size
*
* Format 1: Run-length encoding; the high nibble holds the number of
* white bits, the low nibble the number of black bits. In
* other words, a single byte can represent at most 15
* pixels.
*
* xsize * ysize <= 15 * gps_size
*
* Format 2: Run-length encoding; the high byte holds the number of
* white bits, the low byte the number of black bits. In
* other words, two bytes can represent at most 255 pixels.
*
* xsize * ysize <= 255 * (gps_size + 1) / 2
*/
switch ( format )
{
case 0:
if ( ( (FT_ULong)xsize * ysize + 7 ) / 8 > gps_size )
error = FT_THROW( Invalid_Table );
break;
case 1:
if ( (FT_ULong)xsize * ysize > 15 * gps_size )
error = FT_THROW( Invalid_Table );
break;
case 2:
if ( (FT_ULong)xsize * ysize > 255 * ( ( gps_size + 1 ) / 2 ) )
error = FT_THROW( Invalid_Table );
break;
default:
FT_ERROR(( "pfr_slot_load_bitmap: invalid image type\n" ));
error = FT_THROW( Invalid_Table );
}
if ( error )
{
if ( FT_ERR_EQ( error, Invalid_Table ) )
FT_ERROR(( "pfr_slot_load_bitmap: invalid bitmap dimensions\n" ));
goto Exit1;
}
/*
* XXX: on 16bit systems we return an error for huge bitmaps
* that cause size truncation, because truncated
* size properties make bitmap glyphs broken.
*/
if ( xpos > FT_INT_MAX ||
xpos < FT_INT_MIN ||
ysize > FT_INT_MAX ||
ypos > FT_INT_MAX - (FT_Long)ysize ||
ypos + (FT_Long)ysize < FT_INT_MIN )
{
FT_TRACE1(( "pfr_slot_load_bitmap:" ));
FT_TRACE1(( "huge bitmap glyph %ldx%ld over FT_GlyphSlot\n",
xpos, ypos ));
error = FT_THROW( 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 = xsize;
glyph->root.bitmap.rows = 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 * 64;
glyph->root.metrics.horiBearingY = ypos * 64;
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 + (FT_Long)ysize );
if ( metrics_only )
goto Exit1;
/* Allocate and read bitmap data */
{
FT_ULong len = (FT_ULong)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 &
PFR_FLAG_INVERT_BITMAP ),
&glyph->root.bitmap );
}
}
Exit1:
FT_FRAME_EXIT();
}
Exit:
return error;
}
/* END */