.TH LIBPARSEPCF_GET_ACCELERATORS 3 LIBPARSEPCF
.SH NAME
libparsepcf_get_accelerators \- Get font information
.SH SYNOPSIS
.nf
#include <libparsepcf.h>
#define LIBPARSEPCF_ACCELERATORS /* value omitted */
#define LIBPARSEPCF_BDF_ACCELERATORS /* value omitted */
struct libparsepcf_accelerators {
uint8_t \fIno_overlap\fP : 1;
uint8_t \fIconstant_metrics\fP : 1;
uint8_t \fIterminal_font\fP : 1;
uint8_t \fIconstant_width\fP : 1;
uint8_t \fIink_inside\fP : 1;
uint8_t \fIink_metrics\fP : 1;
uint8_t \fIdraw_rtl\fP : 1;
uint8_t \fIhave_ink_bounds\fP : 1;
int32_t \fIfont_ascent\fP;
int32_t \fIfont_descent\fP;
int32_t \fImax_overlap\fP;
struct libparsepcf_metrics \fImin_bounds\fP;
struct libparsepcf_metrics \fImax_bounds\fP;
struct libparsepcf_metrics \fImin_ink_bounds\fP;
struct libparsepcf_metrics \fImax_ink_bounds\fP;
};
int libparsepcf_get_accelerators(const void *\fIdata\fP, size_t \fIsize\fP,
const struct libparsepcf_table *\fItable\fP,
struct libparsepcf_accelerators *\fImeta_out\fP);
.fi
.PP
Link with
.IR -lparsepcf .
.SH DESCRIPTION
A PCF font files may record overall font
information, intended for optimisations,
in the tables with the types
.B LIBPARSEPCF_ACCELERATORS
and
.B LIBPARSEPCF_BDF_ACCELERATORS
which can be retrieved with the
.BR libparsepcf_get_tables (3)
function. If both tables are present,
.B LIBPARSEPCF_BDF_ACCELERATORS
shall be preferred, it is more accurate
and only refers to the encoded characters
in the font, whereas
.B LIBPARSEPCF_ACCELERATORS
includes all glyphs (not that the fallback
glyph do not necessarily correspond to an
encoded character).
.PP
Once the
.B LIBPARSEPCF_ACCELERATORS
or
.B LIBPARSEPCF_BDF_ACCELERATORS
table has been identified, it can be passed as
the third argument
.RI ( table )
to the
.BR libparsepcf_get_accelerators ()
function along with the font file contents in the
.I data
argument and size, in bytes, of the file in the
.I size
argument. The
.BR libparsepcf_get_accelerators ()
function will store the font information in
.IR *meta_out .
.PP
The following information will be stored in
.IR *meta_out :
.TP
.I no_overlap
If 1, then for each glyph, the layout metrics,
.IR mtx ,
.I mtx.right_side_bearing - mtx.character_width
will not be greater than
.IR meta_out->min_bounds.left_side_bearing .
.TP
.I constant_width
If 1, all glyph have the same layout width.
.TP
.I constant_metrics
If 1, all glyphs have the same layout metrics.
.TP
.I terminal_font
If 1, all glyphs have the same layout metrics
and for each glyph, the layout left-side bearing is 0,
the layout right-side bearing is the layout width,
the layout ascent is
.IR meta_out->font_ascent ,
and the layout descent is
.IR meta_out->font_descent .
.TP
.I ink_inside
If 1, no glyph will have ink outside the
glyph's layout box.
.TP
.I ink_metrics
If 1, at least one glyph have ink metrics
different from the layout metrics.
.TP
.I draw_rtl
If 1, the font is a right-to-left font,
if 0, the font is a left-to-right font.
.TP
.I have_ink_bounds
If 0, the function copied
.I meta_out->min_bounds
into
.I meta_out->min_ink_bounds
and
.I meta_out->max_bounds
into
.IR meta_out->max_ink_bounds .
.TP
.I font_ascent
The number of pixels the font ascend above the baseline.
.TP
.I font_descent
The number of pixels the font descend below the baseline.
.TP
.I max_overlap
The maximum horizontal overlap, in pixels, of two glyph.
.TP
.I min_bounds
The lower bounds, over each glyph, of the layout metrics.
.TP
.I max_bounds
The upper bounds, over each glyph, of the layout metrics.
.TP
.I min_ink_bounds
The lower bounds, over each glyph, of the ink metrics.
.TP
.I max_ink_bounds
The upper bounds, over each glyph, of the ink metrics.
.SH RETURN VALUE
The
.BR libparsepcf_get_accelerators ()
function returns 0 upon successful completion.
On failure, -1 is returned and
.I errno
is set appropriately to indicate the error.
.SH ERRORS
The
.BR libparsepcf_get_accelerators ()
function fails if:
.TP
.B EBFONT
The font file is corrupt or unsupported.
.SH SEE ALSO
.BR libparsepcf (7),
.BR libparsepcf_preparse_font (3)
