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Diffstat (limited to 'libparsepcf_get_accelerators.3')
| -rw-r--r-- | libparsepcf_get_accelerators.3 | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/libparsepcf_get_accelerators.3 b/libparsepcf_get_accelerators.3 new file mode 100644 index 0000000..a68c6f4 --- /dev/null +++ b/libparsepcf_get_accelerators.3 @@ -0,0 +1,161 @@ +.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) |