diff options
Diffstat (limited to 'libparsepcf.h')
| -rw-r--r-- | libparsepcf.h | 109 |
1 files changed, 92 insertions, 17 deletions
diff --git a/libparsepcf.h b/libparsepcf.h index eef98c8..f7e6941 100644 --- a/libparsepcf.h +++ b/libparsepcf.h @@ -9,7 +9,6 @@ /* Based on documentation from FontForge: https://fontforge.org/docs/techref/pcf-format.html */ - /** * Table metadata */ @@ -399,28 +398,113 @@ struct libparsepcf_bitmaps { /** * The size of `.bitmap_data` + * + * Used internally to detect corruption */ size_t bitmap_size; + /** + * For each row in a glyph, cells' ink status are + * encoded in bits that are packed into groups of + * units, and the bits are ordered according to + * `.msbit_first` within each group. This field + * specifies the number of bytes in each group. + * + * This will always be a power of two and + * no greater than `.row_padding` + */ size_t bit_packing; /** - * The number of bytes each row is - * padded to align to + * The number of bytes each row is padded to align to * * This will always be a power of two */ size_t row_padding; - int lsbyte; - int lsbit; + /** + * This field specify the order of the bytes for + * each group of bits as described in the documentation + * of `.bit_packing`. The value will be either 0 or 1 + * + * If 0, the bytes in each glyph cell group is ordered + * such that the least significant bit octet is stored + * in the first byte + * + * If 1, the bytes in each glyph cell group is ordered + * such that the least significant bit octet is stored + * in the first byte + */ + int msbyte_first; /* called "lsbyte" in 1.0 */ + + /** + * Will either be 0 or 1 + * + * If 0, glyph cells (left to right) are encoded from + * the least significant bit to the most significant + * bit within each byte + * + * If 1, glyph cells (left to right) are encoded from + * the most significant bit to the least significant + * bit within each byte + */ + int msbit_first; /* called "lsbit" in 1.0 */ + + /** + * Bitmap data, `libparsepcf_get_bitmap_offsets` should be + * be used to find where in this buffer the bitmap for a + * particular glyph begins, and the `LIBPARSEPCF_INK_METRICS` + * table shall be used (along with information in this + * structure) to decode the bitmap data; if the table + * `LIBPARSEPCF_INK_METRICS` is missing the + * `LIBPARSEPCF_METRICS` (layout metrics) should be used + * instead + * + * Bitmaps are in row-major order, top to bottom, + * and in column-minor order, left to right + * + * Set bits represent ink-on, cleared bits represent ink-off + */ const uint8_t *bitmap_data; }; +/** + * Get the bitmaps metadata for the glyphs in the file + * + * @param file The file content + * @param size The file size + * @param table The table in the file with the `.type` `LIBPARSEPCF_BITMAPS`, + * extracted using the `libparsepcf_get_tables` function + * @param meta Output parameter for the glyph bitmap metadata + * @return 0 on success, -1 on failure + * + * @throws EBFONT The file is not a properly formatted PCF file + */ int libparsepcf_get_bitmaps(const void *, size_t, const struct libparsepcf_table *, struct libparsepcf_bitmaps *); +/** + * Get the offsets to the bitmaps for glyphs in the file + * + * The first four arguments shall be the same as + * passed into `libparsepcf_get_bitmaps` + * + * @param file The file content + * @param size The file size + * @param table The table in the file with the `.type` `LIBPARSEPCF_BITMAPS`, + * extracted using the `libparsepcf_get_tables` function + * @param meta Glyph bitmap metadata + * @param offs Output parameter for the bitmap offsets + * @param first The index of the first glyph whose bitmap offset to store + * in `offs`, the first glyph in the file has the index 0 + * @param count The number of glyphs whose bitmap offsets to store in `offs`; + * may not exceed the number of properties (`.glyph_count`) + * as retrieved by `libparsepcf_get_bitmaps` minus `first` + * @return 0 on success, -1 on failure + * + * @throws EBFONT The file is not a properly formatted PCF file + */ int libparsepcf_get_bitmap_offsets(const void *, size_t, const struct libparsepcf_table *, const struct libparsepcf_bitmaps *, @@ -501,25 +585,16 @@ struct libparsepcf_encoding { * field does not necessarily correspond to a * character and thus may not be available in the * encoding table - * - * This name of this field is choosen for consistence - * with the documentation the implementation is based - * on, and is confusing, it ought to be called - * "default_glyph" */ - uint16_t default_char; + uint16_t default_glyph; /* called "default_char" in 1.0 */ /** * The number of entries available in the index table, * this is not number of glyphs in the file, but rather * the product of `.max_byte2 - .min_byte2 + 1` and - * `.max_byte1 - .min_byte1 + 1`. - * - * This name of this field is choosen for consistence - * with the documentation the implementation is based - * on, and is confusing, it ought to be called "char_count" + * `.max_byte1 - .min_byte1 + 1` */ - size_t glyph_count; + size_t char_count; /* called "glyph_count" in 1.0 */ }; /** |