📄 ttsbit.c
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{
if ( (FT_UInt)range->glyph_codes[n] == glyph_index )
{
if ( range->index_format == 4 )
*aglyph_offset = range->glyph_offsets[n];
else
*aglyph_offset = range->image_offset +
n * range->image_size;
goto Found;
}
}
}
/* fall-through */
default:
goto Fail;
}
Found:
/* return successfully! */
*arange = range;
return 0;
}
}
Fail:
*arange = 0;
*aglyph_offset = 0;
return SFNT_Err_Invalid_Argument;
}
/*************************************************************************/
/* */
/* <Function> */
/* tt_find_sbit_image */
/* */
/* <Description> */
/* Checks whether an embedded bitmap (an `sbit') exists for a given */
/* glyph, at a given strike. */
/* */
/* <Input> */
/* face :: The target face object. */
/* */
/* glyph_index :: The glyph index. */
/* */
/* strike_index :: The current strike index. */
/* */
/* <Output> */
/* arange :: The SBit range containing the glyph index. */
/* */
/* astrike :: The SBit strike containing the glyph index. */
/* */
/* aglyph_offset :: The offset of the glyph data in `EBDT' table. */
/* */
/* <Return> */
/* FreeType error code. 0 means success. Returns */
/* SFNT_Err_Invalid_Argument if no sbit exists for the requested */
/* glyph. */
/* */
FT_LOCAL( FT_Error )
tt_find_sbit_image( TT_Face face,
FT_UInt glyph_index,
FT_ULong strike_index,
TT_SBit_Range *arange,
TT_SBit_Strike *astrike,
FT_ULong *aglyph_offset )
{
FT_Error error;
TT_SBit_Strike strike;
if ( !face->sbit_strikes ||
( face->num_sbit_strikes <= strike_index ) )
goto Fail;
strike = &face->sbit_strikes[strike_index];
error = find_sbit_range( glyph_index, strike,
arange, aglyph_offset );
if ( error )
goto Fail;
*astrike = strike;
return SFNT_Err_Ok;
Fail:
/* no embedded bitmap for this glyph in face */
*arange = 0;
*astrike = 0;
*aglyph_offset = 0;
return SFNT_Err_Invalid_Argument;
}
/*************************************************************************/
/* */
/* <Function> */
/* tt_load_sbit_metrics */
/* */
/* <Description> */
/* Gets the big metrics for a given SBit. */
/* */
/* <Input> */
/* stream :: The input stream. */
/* */
/* range :: The SBit range containing the glyph. */
/* */
/* <Output> */
/* big_metrics :: A big SBit metrics structure for the glyph. */
/* */
/* <Return> */
/* FreeType error code. 0 means success. */
/* */
/* <Note> */
/* The stream cursor must be positioned at the glyph's offset within */
/* the `EBDT' table before the call. */
/* */
/* If the image format uses variable metrics, the stream cursor is */
/* positioned just after the metrics header in the `EBDT' table on */
/* function exit. */
/* */
FT_LOCAL( FT_Error )
tt_load_sbit_metrics( FT_Stream stream,
TT_SBit_Range range,
TT_SBit_Metrics metrics )
{
FT_Error error = SFNT_Err_Ok;
switch ( range->image_format )
{
case 1:
case 2:
case 8:
/* variable small metrics */
{
TT_SBit_SmallMetricsRec smetrics;
static const FT_Frame_Field sbit_small_metrics_fields[] =
{
#undef FT_STRUCTURE
#define FT_STRUCTURE TT_SBit_SmallMetricsRec
FT_FRAME_START( 5 ),
FT_FRAME_BYTE( height ),
FT_FRAME_BYTE( width ),
FT_FRAME_CHAR( bearingX ),
FT_FRAME_CHAR( bearingY ),
FT_FRAME_BYTE( advance ),
FT_FRAME_END
};
/* read small metrics */
if ( FT_STREAM_READ_FIELDS( sbit_small_metrics_fields, &smetrics ) )
goto Exit;
/* convert it to a big metrics */
metrics->height = smetrics.height;
metrics->width = smetrics.width;
metrics->horiBearingX = smetrics.bearingX;
metrics->horiBearingY = smetrics.bearingY;
metrics->horiAdvance = smetrics.advance;
/* these metrics are made up at a higher level when */
/* needed. */
metrics->vertBearingX = 0;
metrics->vertBearingY = 0;
metrics->vertAdvance = 0;
}
break;
case 6:
case 7:
case 9:
/* variable big metrics */
if ( FT_STREAM_READ_FIELDS( sbit_metrics_fields, metrics ) )
goto Exit;
break;
case 5:
default: /* constant metrics */
if ( range->index_format == 2 || range->index_format == 5 )
*metrics = range->metrics;
else
return SFNT_Err_Invalid_File_Format;
}
Exit:
return error;
}
/*************************************************************************/
/* */
/* <Function> */
/* crop_bitmap */
/* */
/* <Description> */
/* Crops a bitmap to its tightest bounding box, and adjusts its */
/* metrics. */
/* */
/* <InOut> */
/* map :: The bitmap. */
/* */
/* metrics :: The corresponding metrics structure. */
/* */
static void
crop_bitmap( FT_Bitmap* map,
TT_SBit_Metrics metrics )
{
/***********************************************************************/
/* */
/* In this situation, some bounding boxes of embedded bitmaps are too */
/* large. We need to crop it to a reasonable size. */
/* */
/* --------- */
/* | | ----- */
/* | *** | |***| */
/* | * | | * | */
/* | * | ------> | * | */
/* | * | | * | */
/* | * | | * | */
/* | *** | |***| */
/* --------- ----- */
/* */
/***********************************************************************/
FT_Int rows, count;
FT_Long line_len;
FT_Byte* line;
/***********************************************************************/
/* */
/* first of all, check the top-most lines of the bitmap, and remove */
/* them if they're empty. */
/* */
{
line = (FT_Byte*)map->buffer;
rows = map->rows;
line_len = map->pitch;
for ( count = 0; count < rows; count++ )
{
FT_Byte* cur = line;
FT_Byte* limit = line + line_len;
for ( ; cur < limit; cur++ )
if ( cur[0] )
goto Found_Top;
/* the current line was empty - skip to next one */
line = limit;
}
Found_Top:
/* check that we have at least one filled line */
if ( count >= rows )
goto Empty_Bitmap;
/* now, crop the empty upper lines */
if ( count > 0 )
{
line = (FT_Byte*)map->buffer;
FT_MEM_MOVE( line, line + count * line_len,
( rows - count ) * line_len );
metrics->height = (FT_Byte)( metrics->height - count );
metrics->horiBearingY = (FT_Char)( metrics->horiBearingY - count );
metrics->vertBearingY = (FT_Char)( metrics->vertBearingY - count );
map->rows -= count;
rows -= count;
}
}
/***********************************************************************/
/* */
/* second, crop the lower lines */
/* */
{
line = (FT_Byte*)map->buffer + ( rows - 1 ) * line_len;
for ( count = 0; count < rows; count++ )
{
FT_Byte* cur = line;
FT_Byte* limit = line + line_len;
for ( ; cur < limit; cur++ )
if ( cur[0] )
goto Found_Bottom;
/* the current line was empty - skip to previous one */
line -= line_len;
}
Found_Bottom:
if ( count > 0 )
{
metrics->height = (FT_Byte)( metrics->height - count );
rows -= count;
map->rows -= count;
}
}
/***********************************************************************/
/* */
/* third, get rid of the space on the left side of the glyph */
/* */
do
{
FT_Byte* limit;
line = (FT_Byte*)map->buffer;
limit = line + rows * line_len;
for ( ; line < limit; line += line_len )
if ( line[0] & 0x80 )
goto Found_Left;
/* shift the whole glyph one pixel to the left */
line = (FT_Byte*)map->buffer;
limit = line + rows * line_len;
for ( ; line < limit; line += line_len )
{
FT_Int n, width = map->width;
FT_Byte old;
FT_Byte* cur = line;
old = (FT_Byte)(cur[0] << 1);
for ( n = 8; n < width; n += 8 )
{
FT_Byte val;
val = cur[1];
cur[0] = (FT_Byte)( old | ( val >> 7 ) );
old = (FT_Byte)( val << 1 );
cur++;
}
cur[0] = old;
}
map->width--;
metrics->horiBearingX++;
metrics->vertBearingX++;
metrics->width--;
} while ( map->width > 0 );
Found_Left:
/***********************************************************************/
/* */
/* finally, crop the bitmap width to get rid of the space on the right */
/* side of the glyph. */
/* */
do
{
FT_Int right = map->width - 1;
FT_Byte* limit;
FT_Byte mask;
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