Add `FT_FACE_FLAG_SBIX_OVERLAY` and `FT_HAS_SBIX_OVERLAY`.
* include/freetype/freetype.h (FT_FACE_FLAG_SBIX_OVERLAY, FT_HAS_SBIX_OVERLAY): New macro. * src/sfnt/ttsbit.c (tt_face_load_sbit): Handle `FT_FACE_FLAG_SBIX_OVERLAY`. Remove obsolete tracing message.
This commit is contained in:
Werner Lemberg
parent
1949a7ec3a
commit
a8e4563c34
|
|
@ -155,6 +155,7 @@ FT_BEGIN_HEADER
|
|||
* FT_FACE_FLAG_HINTER
|
||||
* FT_FACE_FLAG_SVG
|
||||
* FT_FACE_FLAG_SBIX
|
||||
* FT_FACE_FLAG_SBIX_OVERLAY
|
||||
*
|
||||
* FT_HAS_HORIZONTAL
|
||||
* FT_HAS_VERTICAL
|
||||
|
|
@ -165,6 +166,7 @@ FT_BEGIN_HEADER
|
|||
* FT_HAS_MULTIPLE_MASTERS
|
||||
* FT_HAS_SVG
|
||||
* FT_HAS_SBIX
|
||||
* FT_HAS_SBIX_OVERLAY
|
||||
*
|
||||
* FT_IS_SFNT
|
||||
* FT_IS_SCALABLE
|
||||
|
|
@ -1244,6 +1246,10 @@ FT_BEGIN_HEADER
|
|||
* For such fonts, @FT_FACE_FLAG_SCALABLE is not set by default to
|
||||
* retain backward compatibility.
|
||||
*
|
||||
* FT_FACE_FLAG_SBIX_OVERLAY ::
|
||||
* [Since 2.12] The face has an 'sbix' OpenType table where outlines
|
||||
* should be drawn on top of bitmap strikes.
|
||||
*
|
||||
*/
|
||||
#define FT_FACE_FLAG_SCALABLE ( 1L << 0 )
|
||||
#define FT_FACE_FLAG_FIXED_SIZES ( 1L << 1 )
|
||||
|
|
@ -1263,6 +1269,7 @@ FT_BEGIN_HEADER
|
|||
#define FT_FACE_FLAG_VARIATION ( 1L << 15 )
|
||||
#define FT_FACE_FLAG_SVG ( 1L << 16 )
|
||||
#define FT_FACE_FLAG_SBIX ( 1L << 17 )
|
||||
#define FT_FACE_FLAG_SBIX_OVERLAY ( 1L << 18 )
|
||||
|
||||
|
||||
/**************************************************************************
|
||||
|
|
@ -1528,6 +1535,73 @@ FT_BEGIN_HEADER
|
|||
* A macro that returns true whenever a face object contains an 'sbix'
|
||||
* OpenType table *and* outline glyphs.
|
||||
*
|
||||
* Currently, FreeType only supports bitmap glyphs in PNG format for this
|
||||
* table (i.e., JPEG and TIFF formats are unsupported, as are
|
||||
* Apple-specific formats not part of the OpenType specification).
|
||||
*
|
||||
* @note:
|
||||
* For backward compatibility, a font with an 'sbix' table is treated as
|
||||
* a bitmap-only face. Using @FT_Open_Face with @FT_PARAM_TAG_NO_SBIX,
|
||||
* an application can switch off 'sbix' handling so that the face is
|
||||
* treated as an ordinary outline font with scalable outlines.
|
||||
*
|
||||
* Here is some pseudo code that roughly illustrates how to implement
|
||||
* 'sbix' handling according to the OpenType specification.
|
||||
*
|
||||
* ```
|
||||
* if ( FT_HAS_SBIX( face ) )
|
||||
* {
|
||||
* // open font as a scalable one without sbix handling
|
||||
* FT_Face face2;
|
||||
* FT_Parameter param = { FT_PARAM_TAG_IGNORE_SBIX, NULL };
|
||||
* FT_Open_Args args = { FT_OPEN_PARAMS | ...,
|
||||
* ...,
|
||||
* 1, ¶m };
|
||||
*
|
||||
*
|
||||
* FT_Open_Face( library, &args, 0, &face2 );
|
||||
*
|
||||
* <sort `face->available_size` as necessary into
|
||||
* `preferred_sizes`[*]>
|
||||
*
|
||||
* for ( i = 0; i < face->num_fixed_sizes; i++ )
|
||||
* {
|
||||
* size = preferred_sizes[i].size;
|
||||
*
|
||||
* error = FT_Set_Pixel_Sizes( face, size, size );
|
||||
* <error handling omitted>
|
||||
*
|
||||
* // check whether we have a glyph in a bitmap strike
|
||||
* error = FT_Load_Glyph( face,
|
||||
* glyph_index,
|
||||
* FT_LOAD_SBITS_ONLY |
|
||||
* FT_LOAD_BITMAP_METRICS_ONLY );
|
||||
* if ( error == FT_Err_Invalid_Argument )
|
||||
* continue;
|
||||
* else if ( error )
|
||||
* <other error handling omitted>
|
||||
* else
|
||||
* break;
|
||||
* }
|
||||
*
|
||||
* if ( i != face->num_fixed_sizes )
|
||||
* <load embedded bitmap with `FT_Load_Glyph`,
|
||||
* scale it, display it, etc.>
|
||||
*
|
||||
* if ( i == face->num_fixed_sizes ||
|
||||
* FT_HAS_SBIX_OVERLAY( face ) )
|
||||
* <use `face2` to load outline glyph with `FT_Load_Glyph`,
|
||||
* scale it, display it on top of the bitmap, etc.>
|
||||
* }
|
||||
* ```
|
||||
*
|
||||
* [*] Assuming a target value of 400dpi and available strike sizes 100,
|
||||
* 200, 300, and 400dpi, a possible order might be [400, 200, 300, 100]:
|
||||
* scaling 200dpi to 400dpi usually gives better results than scaling
|
||||
* 300dpi to 400dpi; it is also much faster. However, scaling 100dpi to
|
||||
* 400dpi can yield a too pixelated result, thus the preference might be
|
||||
* 300dpi over 100dpi.
|
||||
*
|
||||
* @since:
|
||||
* 2.12
|
||||
*/
|
||||
|
|
@ -1535,6 +1609,24 @@ FT_BEGIN_HEADER
|
|||
( !!( (face)->face_flags & FT_FACE_FLAG_SBIX ) )
|
||||
|
||||
|
||||
/**************************************************************************
|
||||
*
|
||||
* @macro:
|
||||
* FT_HAS_SBIX_OVERLAY
|
||||
*
|
||||
* @description:
|
||||
* A macro that returns true whenever a face object contains an 'sbix'
|
||||
* OpenType table with bit~1 in its `flags` field set, instructing the
|
||||
* application to overlay the bitmap strike with the corresponding
|
||||
* outline glyph. See @FT_HAS_SBIX for pseudo code how to use it.
|
||||
*
|
||||
* @since:
|
||||
* 2.12
|
||||
*/
|
||||
#define FT_HAS_SBIX_OVERLAY( face ) \
|
||||
( !!( (face)->face_flags & FT_FACE_FLAG_SBIX_OVERLAY ) )
|
||||
|
||||
|
||||
/**************************************************************************
|
||||
*
|
||||
* @enum:
|
||||
|
|
|
|||
|
|
@ -172,17 +172,8 @@
|
|||
goto Exit;
|
||||
}
|
||||
|
||||
#ifdef FT_DEBUG_LEVEL_TRACE
|
||||
/* we currently don't support bit 1; however, it is better to */
|
||||
/* draw at least something... */
|
||||
if ( flags == 3 )
|
||||
{
|
||||
FT_TRACE1(( "tt_face_load_sbit_strikes:"
|
||||
" sbix overlay not supported yet\n" ));
|
||||
FT_TRACE1(( " "
|
||||
" expect bad rendering results\n" ));
|
||||
}
|
||||
#endif
|
||||
face->root.face_flags |= FT_FACE_FLAG_SBIX_OVERLAY;
|
||||
|
||||
/*
|
||||
* Count the number of strikes available in the table. We are a bit
|
||||
|
|
|
|||
Loading…
Reference in New Issue