📄 ttsbit.c
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line = (FT_Byte*)map->buffer + ( right >> 3 );
limit = line + rows * line_len;
mask = (FT_Byte)( 0x80 >> ( right & 7 ) );
for ( ; line < limit; line += line_len )
if ( line[0] & mask )
goto Found_Right;
/* crop the whole glyph to the right */
map->width--;
metrics->width--;
} while ( map->width > 0 );
Found_Right:
/* all right, the bitmap was cropped */
return;
Empty_Bitmap:
map->width = 0;
map->rows = 0;
map->pitch = 0;
map->pixel_mode = FT_PIXEL_MODE_MONO;
}
static FT_Error
Load_SBit_Single( FT_Bitmap* map,
FT_Int x_offset,
FT_Int y_offset,
FT_Int pix_bits,
FT_UShort image_format,
TT_SBit_Metrics metrics,
FT_Stream stream )
{
FT_Error error;
/* check that the source bitmap fits into the target pixmap */
if ( x_offset < 0 || x_offset + metrics->width > map->width ||
y_offset < 0 || y_offset + metrics->height > map->rows )
{
error = SFNT_Err_Invalid_Argument;
goto Exit;
}
{
FT_Int glyph_width = metrics->width;
FT_Int glyph_height = metrics->height;
FT_Int glyph_size;
FT_Int line_bits = pix_bits * glyph_width;
FT_Bool pad_bytes = 0;
/* compute size of glyph image */
switch ( image_format )
{
case 1: /* byte-padded formats */
case 6:
{
FT_Int line_length;
switch ( pix_bits )
{
case 1:
line_length = ( glyph_width + 7 ) >> 3;
break;
case 2:
line_length = ( glyph_width + 3 ) >> 2;
break;
case 4:
line_length = ( glyph_width + 1 ) >> 1;
break;
default:
line_length = glyph_width;
}
glyph_size = glyph_height * line_length;
pad_bytes = 1;
}
break;
case 2:
case 5:
case 7:
line_bits = glyph_width * pix_bits;
glyph_size = ( glyph_height * line_bits + 7 ) >> 3;
break;
default: /* invalid format */
return SFNT_Err_Invalid_File_Format;
}
/* Now read data and draw glyph into target pixmap */
if ( FT_FRAME_ENTER( glyph_size ) )
goto Exit;
/* don't forget to multiply `x_offset' by `map->pix_bits' as */
/* the sbit blitter doesn't make a difference between pixmap */
/* depths. */
blit_sbit( map, (FT_Byte*)stream->cursor, line_bits, pad_bytes,
x_offset * pix_bits, y_offset );
FT_FRAME_EXIT();
}
Exit:
return error;
}
static FT_Error
Load_SBit_Image( TT_SBit_Strike strike,
TT_SBit_Range range,
FT_ULong ebdt_pos,
FT_ULong glyph_offset,
FT_GlyphSlot slot,
FT_Int x_offset,
FT_Int y_offset,
FT_Stream stream,
TT_SBit_Metrics metrics,
FT_Int depth )
{
FT_Memory memory = stream->memory;
FT_Bitmap* map = &slot->bitmap;
FT_Error error;
/* place stream at beginning of glyph data and read metrics */
if ( FT_STREAM_SEEK( ebdt_pos + glyph_offset ) )
goto Exit;
error = tt_load_sbit_metrics( stream, range, metrics );
if ( error )
goto Exit;
/* This function is recursive. At the top-level call, we */
/* compute the dimensions of the higher-level glyph to */
/* allocate the final pixmap buffer. */
if ( depth == 0 )
{
FT_Long size;
map->width = metrics->width;
map->rows = metrics->height;
switch ( strike->bit_depth )
{
case 1:
map->pixel_mode = FT_PIXEL_MODE_MONO;
map->pitch = ( map->width + 7 ) >> 3;
break;
case 2:
map->pixel_mode = FT_PIXEL_MODE_GRAY2;
map->pitch = ( map->width + 3 ) >> 2;
break;
case 4:
map->pixel_mode = FT_PIXEL_MODE_GRAY4;
map->pitch = ( map->width + 1 ) >> 1;
break;
case 8:
map->pixel_mode = FT_PIXEL_MODE_GRAY;
map->pitch = map->width;
break;
default:
return SFNT_Err_Invalid_File_Format;
}
size = map->rows * map->pitch;
/* check that there is no empty image */
if ( size == 0 )
goto Exit; /* exit successfully! */
error = ft_glyphslot_alloc_bitmap( slot, size );
if (error)
goto Exit;
}
switch ( range->image_format )
{
case 1: /* single sbit image - load it */
case 2:
case 5:
case 6:
case 7:
return Load_SBit_Single( map, x_offset, y_offset, strike->bit_depth,
range->image_format, metrics, stream );
case 8: /* compound format */
FT_Stream_Skip( stream, 1L );
/* fallthrough */
case 9:
break;
default: /* invalid image format */
return SFNT_Err_Invalid_File_Format;
}
/* All right, we have a compound format. First of all, read */
/* the array of elements. */
{
TT_SBit_Component components;
TT_SBit_Component comp;
FT_UShort num_components, count;
if ( FT_READ_USHORT( num_components ) ||
FT_NEW_ARRAY( components, num_components ) )
goto Exit;
count = num_components;
if ( FT_FRAME_ENTER( 4L * num_components ) )
goto Fail_Memory;
for ( comp = components; count > 0; count--, comp++ )
{
comp->glyph_code = FT_GET_USHORT();
comp->x_offset = FT_GET_CHAR();
comp->y_offset = FT_GET_CHAR();
}
FT_FRAME_EXIT();
/* Now recursively load each element glyph */
count = num_components;
comp = components;
for ( ; count > 0; count--, comp++ )
{
TT_SBit_Range elem_range;
TT_SBit_MetricsRec elem_metrics;
FT_ULong elem_offset;
/* find the range for this element */
error = find_sbit_range( comp->glyph_code,
strike,
&elem_range,
&elem_offset );
if ( error )
goto Fail_Memory;
/* now load the element, recursively */
error = Load_SBit_Image( strike,
elem_range,
ebdt_pos,
elem_offset,
slot,
x_offset + comp->x_offset,
y_offset + comp->y_offset,
stream,
&elem_metrics,
depth + 1 );
if ( error )
goto Fail_Memory;
}
Fail_Memory:
FT_FREE( components );
}
Exit:
return error;
}
/*************************************************************************/
/* */
/* <Function> */
/* tt_face_load_sbit_image */
/* */
/* <Description> */
/* Loads a given glyph sbit image from the font resource. This also */
/* returns its metrics. */
/* */
/* <Input> */
/* face :: The target face object. */
/* */
/* strike_index :: The current strike index. */
/* */
/* glyph_index :: The current glyph index. */
/* */
/* load_flags :: The glyph load flags (the code checks for the flag */
/* FT_LOAD_CROP_BITMAP). */
/* */
/* stream :: The input stream. */
/* */
/* <Output> */
/* map :: The target pixmap. */
/* */
/* metrics :: A big sbit metrics structure for the glyph image. */
/* */
/* <Return> */
/* FreeType error code. 0 means success. Returns an error if no */
/* glyph sbit exists for the index. */
/* */
/* <Note> */
/* The `map.buffer' field is always freed before the glyph is loaded. */
/* */
FT_LOCAL_DEF( FT_Error )
tt_face_load_sbit_image( TT_Face face,
FT_ULong strike_index,
FT_UInt glyph_index,
FT_UInt load_flags,
FT_Stream stream,
FT_Bitmap *map,
TT_SBit_MetricsRec *metrics )
{
FT_Error error;
FT_ULong ebdt_pos, glyph_offset;
TT_SBit_Strike strike;
TT_SBit_Range range;
/* Check whether there is a glyph sbit for the current index */
error = tt_find_sbit_image( face, glyph_index, strike_index,
&range, &strike, &glyph_offset );
if ( error )
goto Exit;
/* now, find the location of the `EBDT' table in */
/* the font file */
error = face->goto_table( face, TTAG_EBDT, stream, 0 );
if ( error )
error = face->goto_table( face, TTAG_bdat, stream, 0 );
if ( error )
goto Exit;
ebdt_pos = FT_STREAM_POS();
error = Load_SBit_Image( strike, range, ebdt_pos, glyph_offset,
face->root.glyph, 0, 0, stream, metrics, 0 );
if ( error )
goto Exit;
/* setup vertical metrics if needed */
if ( strike->flags & 1 )
{
/* in case of a horizontal strike only */
FT_Int advance;
advance = strike->hori.ascender - strike->hori.descender;
/* some heuristic values */
metrics->vertBearingX = (FT_Char)(-metrics->width / 2 );
metrics->vertBearingY = (FT_Char)( ( advance - metrics->height ) / 2 );
metrics->vertAdvance = (FT_Char)( advance * 12 / 10 );
}
/* Crop the bitmap now, unless specified otherwise */
if ( load_flags & FT_LOAD_CROP_BITMAP )
crop_bitmap( map, metrics );
Exit:
return error;
}
#endif /* !FT_CONFIG_OPTION_OLD_INTERNALS */
/* END */
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