diff options
Diffstat (limited to 'thirdparty/harfbuzz/src/hb-buffer.h')
| -rw-r--r-- | thirdparty/harfbuzz/src/hb-buffer.h | 154 |
1 files changed, 117 insertions, 37 deletions
diff --git a/thirdparty/harfbuzz/src/hb-buffer.h b/thirdparty/harfbuzz/src/hb-buffer.h index a183cb9d4a..ece7d2d8cf 100644 --- a/thirdparty/harfbuzz/src/hb-buffer.h +++ b/thirdparty/harfbuzz/src/hb-buffer.h @@ -76,18 +76,72 @@ typedef struct hb_glyph_info_t { * @HB_GLYPH_FLAG_UNSAFE_TO_BREAK: Indicates that if input text is broken at the * beginning of the cluster this glyph is part of, * then both sides need to be re-shaped, as the - * result might be different. On the flip side, - * it means that when this flag is not present, - * then it's safe to break the glyph-run at the - * beginning of this cluster, and the two sides - * represent the exact same result one would get - * if breaking input text at the beginning of - * this cluster and shaping the two sides - * separately. This can be used to optimize - * paragraph layout, by avoiding re-shaping - * of each line after line-breaking, or limiting - * the reshaping to a small piece around the - * breaking point only. + * result might be different. + * On the flip side, it means that when this + * flag is not present, then it is safe to break + * the glyph-run at the beginning of this + * cluster, and the two sides will represent the + * exact same result one would get if breaking + * input text at the beginning of this cluster + * and shaping the two sides separately. + * This can be used to optimize paragraph + * layout, by avoiding re-shaping of each line + * after line-breaking. + * @HB_GLYPH_FLAG_UNSAFE_TO_CONCAT: Indicates that if input text is changed on one + * side of the beginning of the cluster this glyph + * is part of, then the shaping results for the + * other side might change. + * Note that the absence of this flag will NOT by + * itself mean that it IS safe to concat text. + * Only two pieces of text both of which clear of + * this flag can be concatenated safely. + * This can be used to optimize paragraph + * layout, by avoiding re-shaping of each line + * after line-breaking, by limiting the + * reshaping to a small piece around the + * breaking positin only, even if the breaking + * position carries the + * #HB_GLYPH_FLAG_UNSAFE_TO_BREAK or when + * hyphenation or other text transformation + * happens at line-break position, in the following + * way: + * 1. Iterate back from the line-break position + * until the first cluster start position that is + * NOT unsafe-to-concat, 2. shape the segment from + * there till the end of line, 3. check whether the + * resulting glyph-run also is clear of the + * unsafe-to-concat at its start-of-text position; + * if it is, just splice it into place and the line + * is shaped; If not, move on to a position further + * back that is clear of unsafe-to-concat and retry + * from there, and repeat. + * At the start of next line a similar algorithm can + * be implemented. That is: 1. Iterate forward from + * the line-break position untill the first cluster + * start position that is NOT unsafe-to-concat, 2. + * shape the segment from beginning of the line to + * that position, 3. check whether the resulting + * glyph-run also is clear of the unsafe-to-concat + * at its end-of-text position; if it is, just splice + * it into place and the beginning is shaped; If not, + * move on to a position further forward that is clear + * of unsafe-to-concat and retry up to there, and repeat. + * A slight complication will arise in the + * implementation of the algorithm above, + * because while our buffer API has a way to + * return flags for position corresponding to + * start-of-text, there is currently no position + * corresponding to end-of-text. This limitation + * can be alleviated by shaping more text than needed + * and looking for unsafe-to-concat flag within text + * clusters. + * The #HB_GLYPH_FLAG_UNSAFE_TO_BREAK flag will + * always imply this flag. + * To use this flag, you must enable the buffer flag + * @HB_BUFFER_FLAG_PRODUCE_UNSAFE_TO_CONCAT during + * shaping, otherwise the buffer flag will not be + * reliably produced. + * Since: 4.0.0 * @HB_GLYPH_FLAG_DEFINED: All the currently defined flags. * * Flags for #hb_glyph_info_t. @@ -96,8 +150,9 @@ typedef struct hb_glyph_info_t { */ typedef enum { /*< flags >*/ HB_GLYPH_FLAG_UNSAFE_TO_BREAK = 0x00000001, + HB_GLYPH_FLAG_UNSAFE_TO_CONCAT = 0x00000002, - HB_GLYPH_FLAG_DEFINED = 0x00000001 /* OR of all defined flags */ + HB_GLYPH_FLAG_DEFINED = 0x00000003 /* OR of all defined flags */ } hb_glyph_flags_t; HB_EXTERN hb_glyph_flags_t @@ -170,6 +225,9 @@ hb_segment_properties_equal (const hb_segment_properties_t *a, HB_EXTERN unsigned int hb_segment_properties_hash (const hb_segment_properties_t *p); +HB_EXTERN void +hb_segment_properties_overlay (hb_segment_properties_t *p, + const hb_segment_properties_t *src); /** @@ -185,6 +243,13 @@ HB_EXTERN hb_buffer_t * hb_buffer_create (void); HB_EXTERN hb_buffer_t * +hb_buffer_create_similar (const hb_buffer_t *src); + +HB_EXTERN void +hb_buffer_reset (hb_buffer_t *buffer); + + +HB_EXTERN hb_buffer_t * hb_buffer_get_empty (void); HB_EXTERN hb_buffer_t * @@ -295,7 +360,19 @@ hb_buffer_guess_segment_properties (hb_buffer_t *buffer); * @HB_BUFFER_FLAG_DO_NOT_INSERT_DOTTED_CIRCLE: * flag indicating that a dotted circle should * not be inserted in the rendering of incorrect - * character sequences (such at <0905 093E>). Since: 2.4 + * character sequences (such at <0905 093E>). Since: 2.4.0 + * @HB_BUFFER_FLAG_VERIFY: + * flag indicating that the hb_shape() call and its variants + * should perform various verification processes on the results + * of the shaping operation on the buffer. If the verification + * fails, then either a buffer message is sent, if a message + * handler is installed on the buffer, or a message is written + * to standard error. In either case, the shaping result might + * be modified to show the failed output. Since: 3.4.0 + * @HB_BUFFER_FLAG_PRODUCE_UNSAFE_TO_CONCAT: + * flag indicating that the @HB_GLYPH_FLAG_UNSAFE_TO_CONCAT + * glyph-flag should be produced by the shaper. By default + * it will not be produced since it incurs a cost. Since: 4.0.0 * * Flags for #hb_buffer_t. * @@ -307,7 +384,9 @@ typedef enum { /*< flags >*/ HB_BUFFER_FLAG_EOT = 0x00000002u, /* End-of-text */ HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES = 0x00000004u, HB_BUFFER_FLAG_REMOVE_DEFAULT_IGNORABLES = 0x00000008u, - HB_BUFFER_FLAG_DO_NOT_INSERT_DOTTED_CIRCLE = 0x00000010u + HB_BUFFER_FLAG_DO_NOT_INSERT_DOTTED_CIRCLE = 0x00000010u, + HB_BUFFER_FLAG_VERIFY = 0x00000020u, + HB_BUFFER_FLAG_PRODUCE_UNSAFE_TO_CONCAT = 0x00000040u } hb_buffer_flags_t; HB_EXTERN void @@ -391,8 +470,9 @@ HB_EXTERN hb_codepoint_t hb_buffer_get_not_found_glyph (hb_buffer_t *buffer); -HB_EXTERN void -hb_buffer_reset (hb_buffer_t *buffer); +/* + * Content API. + */ HB_EXTERN void hb_buffer_clear_contents (hb_buffer_t *buffer); @@ -460,7 +540,7 @@ hb_buffer_add_codepoints (hb_buffer_t *buffer, HB_EXTERN void hb_buffer_append (hb_buffer_t *buffer, - hb_buffer_t *source, + const hb_buffer_t *source, unsigned int start, unsigned int end); @@ -557,24 +637,24 @@ hb_buffer_serialize_glyphs (hb_buffer_t *buffer, HB_EXTERN unsigned int hb_buffer_serialize_unicode (hb_buffer_t *buffer, - unsigned int start, - unsigned int end, - char *buf, - unsigned int buf_size, - unsigned int *buf_consumed, - hb_buffer_serialize_format_t format, - hb_buffer_serialize_flags_t flags); + unsigned int start, + unsigned int end, + char *buf, + unsigned int buf_size, + unsigned int *buf_consumed, + hb_buffer_serialize_format_t format, + hb_buffer_serialize_flags_t flags); HB_EXTERN unsigned int hb_buffer_serialize (hb_buffer_t *buffer, - unsigned int start, - unsigned int end, - char *buf, - unsigned int buf_size, - unsigned int *buf_consumed, - hb_font_t *font, - hb_buffer_serialize_format_t format, - hb_buffer_serialize_flags_t flags); + unsigned int start, + unsigned int end, + char *buf, + unsigned int buf_size, + unsigned int *buf_consumed, + hb_font_t *font, + hb_buffer_serialize_format_t format, + hb_buffer_serialize_flags_t flags); HB_EXTERN hb_bool_t hb_buffer_deserialize_glyphs (hb_buffer_t *buffer, @@ -586,10 +666,10 @@ hb_buffer_deserialize_glyphs (hb_buffer_t *buffer, HB_EXTERN hb_bool_t hb_buffer_deserialize_unicode (hb_buffer_t *buffer, - const char *buf, - int buf_len, - const char **end_ptr, - hb_buffer_serialize_format_t format); + const char *buf, + int buf_len, + const char **end_ptr, + hb_buffer_serialize_format_t format); |