ref: d4f4b292ca9c8665ef938036340ff32bf5128755
dir: /libfreetype/pfrsbit.c/
/***************************************************************************/
/* */
/* pfrsbit.c */
/* */
/* FreeType PFR bitmap loader (body). */
/* */
/* Copyright 2002 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] = c;
mask = 0x80;
c = 0;
cur ++;
}
}
if ( mask != 0x80 )
cur[0] = 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] = 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] = 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_Int count,
FT_Byte flags,
FT_UInt char_code,
FT_ULong* found_offset,
FT_ULong* found_size )
{
FT_UInt left, right, char_len;
FT_Bool two = 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 = 0;
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_UInt decreasing,
FT_Bitmap* target )
{
FT_Error error = 0;
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 = FT_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 FT_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 = FT_Err_Invalid_Argument;
goto Exit;
}
}
/* get the bitmap metrics */
{
FT_Long xpos, ypos, advance;
FT_UInt xsize, ysize, format;
FT_Byte* p;
advance = FT_MulDiv( size->root.metrics.x_ppem << 8,
character->advance,
phys->metrics_resolution );
/* XXX: handle linearHoriAdvance correctly! */
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 )
{
glyph->root.format = FT_GLYPH_FORMAT_BITMAP;
/* Set up glyph bitmap and metrics */
glyph->root.bitmap.width = (FT_Int)xsize;
glyph->root.bitmap.rows = (FT_Int)ysize;
glyph->root.bitmap.pitch = (FT_Long)( xsize + 7 ) >> 3;
glyph->root.bitmap.pixel_mode = FT_PIXEL_MODE_MONO;
glyph->root.metrics.width = (FT_Long)xsize << 6;
glyph->root.metrics.height = (FT_Long)ysize << 6;
glyph->root.metrics.horiBearingX = xpos << 6;
glyph->root.metrics.horiBearingY = ypos << 6;
glyph->root.metrics.horiAdvance = ( ( advance >> 2 ) + 32 ) & -64;
glyph->root.metrics.vertBearingX = - glyph->root.metrics.width >> 1;
glyph->root.metrics.vertBearingY = 0;
glyph->root.metrics.vertAdvance = size->root.metrics.height;
glyph->root.bitmap_left = xpos;
glyph->root.bitmap_top = ypos + ysize;
/* Allocate and read bitmap data */
{
FT_Memory memory = face->root.memory;
FT_Long len = glyph->root.bitmap.pitch * ysize;
if ( !FT_ALLOC( glyph->root.bitmap.buffer, len ) )
{
error = pfr_load_bitmap_bits( p,
stream->limit,
format,
face->header.color_flags & 2,
&glyph->root.bitmap );
}
}
}
FT_FRAME_EXIT();
}
Exit:
return error;
}
/* END */