diff options
Diffstat (limited to 'thirdparty/harfbuzz/src/hb-ot-layout.cc')
| -rw-r--r-- | thirdparty/harfbuzz/src/hb-ot-layout.cc | 301 |
1 files changed, 300 insertions, 1 deletions
diff --git a/thirdparty/harfbuzz/src/hb-ot-layout.cc b/thirdparty/harfbuzz/src/hb-ot-layout.cc index a599eea6e9..07bbe3bc84 100644 --- a/thirdparty/harfbuzz/src/hb-ot-layout.cc +++ b/thirdparty/harfbuzz/src/hb-ot-layout.cc @@ -361,6 +361,13 @@ hb_ot_layout_get_attach_points (hb_face_t *face, * Fetches a list of the caret positions defined for a ligature glyph in the GDEF * table of the font. The list returned will begin at the offset provided. * + * Note that a ligature that is formed from n characters will have n-1 + * caret positions. The first character is not represented in the array, + * since its caret position is the glyph position. + * + * The positions returned by this function are 'unshaped', and will have to + * be fixed up for kerning that may be applied to the ligature glyph. + * * Return value: Total number of ligature caret positions for @glyph. * **/ @@ -1960,13 +1967,84 @@ hb_ot_layout_substitute_lookup (OT::hb_ot_apply_context_t *c, #ifndef HB_NO_BASE /** + * hb_ot_layout_get_horizontal_baseline_tag_for_script: + * @script: a script tag. + * + * Fetches the dominant horizontal baseline tag used by @script. + * + * Return value: dominant baseline tag for the @script. + * + * Since: 4.0.0 + **/ +hb_ot_layout_baseline_tag_t +hb_ot_layout_get_horizontal_baseline_tag_for_script (hb_script_t script) +{ + /* Keep in sync with hb_ot_layout_get_baseline_with_fallback */ + switch ((int) script) + { + /* Unicode-1.1 additions */ + case HB_SCRIPT_BENGALI: + case HB_SCRIPT_DEVANAGARI: + case HB_SCRIPT_GUJARATI: + case HB_SCRIPT_GURMUKHI: + /* Unicode-2.0 additions */ + case HB_SCRIPT_TIBETAN: + /* Unicode-4.0 additions */ + case HB_SCRIPT_LIMBU: + /* Unicode-4.1 additions */ + case HB_SCRIPT_SYLOTI_NAGRI: + /* Unicode-5.0 additions */ + case HB_SCRIPT_PHAGS_PA: + /* Unicode-5.2 additions */ + case HB_SCRIPT_MEETEI_MAYEK: + /* Unicode-6.1 additions */ + case HB_SCRIPT_SHARADA: + case HB_SCRIPT_TAKRI: + /* Unicode-7.0 additions */ + case HB_SCRIPT_MODI: + case HB_SCRIPT_SIDDHAM: + case HB_SCRIPT_TIRHUTA: + /* Unicode-9.0 additions */ + case HB_SCRIPT_MARCHEN: + case HB_SCRIPT_NEWA: + /* Unicode-10.0 additions */ + case HB_SCRIPT_SOYOMBO: + case HB_SCRIPT_ZANABAZAR_SQUARE: + /* Unicode-11.0 additions */ + case HB_SCRIPT_DOGRA: + case HB_SCRIPT_GUNJALA_GONDI: + /* Unicode-12.0 additions */ + case HB_SCRIPT_NANDINAGARI: + return HB_OT_LAYOUT_BASELINE_TAG_HANGING; + + /* Unicode-1.1 additions */ + case HB_SCRIPT_HANGUL: + case HB_SCRIPT_HAN: + case HB_SCRIPT_HIRAGANA: + case HB_SCRIPT_KATAKANA: + /* Unicode-3.0 additions */ + case HB_SCRIPT_BOPOMOFO: + /* Unicode-9.0 additions */ + case HB_SCRIPT_TANGUT: + /* Unicode-10.0 additions */ + case HB_SCRIPT_NUSHU: + /* Unicode-13.0 additions */ + case HB_SCRIPT_KHITAN_SMALL_SCRIPT: + return HB_OT_LAYOUT_BASELINE_TAG_IDEO_FACE_BOTTOM_OR_LEFT; + + default: + return HB_OT_LAYOUT_BASELINE_TAG_ROMAN; + } +} + +/** * hb_ot_layout_get_baseline: * @font: a font * @baseline_tag: a baseline tag * @direction: text direction. * @script_tag: script tag. * @language_tag: language tag, currently unused. - * @coord: (out): baseline value if found. + * @coord: (out) (nullable): baseline value if found. * * Fetches a baseline value from the face. * @@ -1989,6 +2067,227 @@ hb_ot_layout_get_baseline (hb_font_t *font, return result; } + +/** + * hb_ot_layout_get_baseline_with_fallback: + * @font: a font + * @baseline_tag: a baseline tag + * @direction: text direction. + * @script_tag: script tag. + * @language_tag: language tag, currently unused. + * @coord: (out): baseline value if found. + * + * Fetches a baseline value from the face, and synthesizes + * it if the font does not have it. + * + * Since: 4.0.0 + **/ +void +hb_ot_layout_get_baseline_with_fallback (hb_font_t *font, + hb_ot_layout_baseline_tag_t baseline_tag, + hb_direction_t direction, + hb_tag_t script_tag, + hb_tag_t language_tag, + hb_position_t *coord /* OUT */) +{ + if (hb_ot_layout_get_baseline (font, + baseline_tag, + direction, + script_tag, + language_tag, + coord)) + return; + + /* Synthesize missing baselines. + * See https://www.w3.org/TR/css-inline-3/#baseline-synthesis-fonts + */ + switch (baseline_tag) + { + case HB_OT_LAYOUT_BASELINE_TAG_ROMAN: + *coord = 0; // FIXME origin ? + break; + + case HB_OT_LAYOUT_BASELINE_TAG_MATH: + { + hb_codepoint_t glyph; + hb_glyph_extents_t extents; + if (HB_DIRECTION_IS_HORIZONTAL (direction) && + (hb_font_get_nominal_glyph (font, 0x2212u, &glyph) || + hb_font_get_nominal_glyph (font, '-', &glyph)) && + hb_font_get_glyph_extents (font, glyph, &extents)) + { + *coord = extents.y_bearing + extents.height / 2; + } + else + { + hb_position_t x_height = 0; + hb_ot_metrics_get_position (font, HB_OT_METRICS_TAG_X_HEIGHT, &x_height); + *coord = x_height / 2; + } + } + break; + + case HB_OT_LAYOUT_BASELINE_TAG_IDEO_FACE_TOP_OR_RIGHT: + case HB_OT_LAYOUT_BASELINE_TAG_IDEO_FACE_BOTTOM_OR_LEFT: + { + hb_position_t embox_top, embox_bottom; + + hb_ot_layout_get_baseline_with_fallback (font, + HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_TOP_OR_RIGHT, + direction, + script_tag, + language_tag, + &embox_top); + hb_ot_layout_get_baseline_with_fallback (font, + HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_BOTTOM_OR_LEFT, + direction, + script_tag, + language_tag, + &embox_bottom); + + if (baseline_tag == HB_OT_LAYOUT_BASELINE_TAG_IDEO_FACE_TOP_OR_RIGHT) + *coord = embox_top + (embox_bottom - embox_top) / 10; + else + *coord = embox_bottom + (embox_top - embox_bottom) / 10; + } + break; + + case HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_TOP_OR_RIGHT: + if (hb_ot_layout_get_baseline (font, + HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_BOTTOM_OR_LEFT, + direction, + script_tag, + language_tag, + coord)) + *coord += HB_DIRECTION_IS_HORIZONTAL (direction) ? font->y_scale : font->x_scale; + else + { + hb_font_extents_t font_extents; + hb_font_get_extents_for_direction (font, direction, &font_extents); + *coord = font_extents.ascender; + } + break; + + case HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_BOTTOM_OR_LEFT: + if (hb_ot_layout_get_baseline (font, + HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_TOP_OR_RIGHT, + direction, + script_tag, + language_tag, + coord)) + *coord -= HB_DIRECTION_IS_HORIZONTAL (direction) ? font->y_scale : font->x_scale; + else + { + hb_font_extents_t font_extents; + hb_font_get_extents_for_direction (font, direction, &font_extents); + *coord = font_extents.descender; + } + break; + + case HB_OT_LAYOUT_BASELINE_TAG_HANGING: + if (HB_DIRECTION_IS_HORIZONTAL (direction)) + { + hb_codepoint_t ch; + hb_codepoint_t glyph; + hb_glyph_extents_t extents; + + /* Keep in sync with hb_ot_layout_get_horizontal_baseline_for_script */ + switch ((int) script_tag) + { + /* Unicode-1.1 additions */ + case HB_SCRIPT_BENGALI: ch = 0x0995u; break; + case HB_SCRIPT_DEVANAGARI: ch = 0x0915u; break; + case HB_SCRIPT_GUJARATI: ch = 0x0a95u; break; + case HB_SCRIPT_GURMUKHI: ch = 0x0a15u; break; + /* Unicode-2.0 additions */ + case HB_SCRIPT_TIBETAN: ch = 0x0f40u; break; + /* Unicode-4.0 additions */ + case HB_SCRIPT_LIMBU: ch = 0x1901u; break; + /* Unicode-4.1 additions */ + case HB_SCRIPT_SYLOTI_NAGRI: ch = 0xa807u; break; + /* Unicode-5.0 additions */ + case HB_SCRIPT_PHAGS_PA: ch = 0xa840u; break; + /* Unicode-5.2 additions */ + case HB_SCRIPT_MEETEI_MAYEK: ch = 0xabc0u; break; + /* Unicode-6.1 additions */ + case HB_SCRIPT_SHARADA: ch = 0x11191u; break; + case HB_SCRIPT_TAKRI: ch = 0x1168cu; break; + /* Unicode-7.0 additions */ + case HB_SCRIPT_MODI: ch = 0x1160eu;break; + case HB_SCRIPT_SIDDHAM: ch = 0x11590u; break; + case HB_SCRIPT_TIRHUTA: ch = 0x1148fu; break; + /* Unicode-9.0 additions */ + case HB_SCRIPT_MARCHEN: ch = 0x11c72u; break; + case HB_SCRIPT_NEWA: ch = 0x1140eu; break; + /* Unicode-10.0 additions */ + case HB_SCRIPT_SOYOMBO: ch = 0x11a5cu; break; + case HB_SCRIPT_ZANABAZAR_SQUARE: ch = 0x11a0bu; break; + /* Unicode-11.0 additions */ + case HB_SCRIPT_DOGRA: ch = 0x1180au; break; + case HB_SCRIPT_GUNJALA_GONDI: ch = 0x11d6cu; break; + /* Unicode-12.0 additions */ + case HB_SCRIPT_NANDINAGARI: ch = 0x119b0u; break; + default: ch = 0; break; + } + + if (ch && + hb_font_get_nominal_glyph (font, ch, &glyph) && + hb_font_get_glyph_extents (font, glyph, &extents)) + *coord = extents.y_bearing; + else + *coord = font->y_scale * 6 / 10; // FIXME makes assumptions about origin + } + else + *coord = font->x_scale * 6 / 10; // FIXME makes assumptions about origin + break; + + case HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_CENTRAL: + { + hb_position_t top, bottom; + hb_ot_layout_get_baseline_with_fallback (font, + HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_TOP_OR_RIGHT, + direction, + script_tag, + language_tag, + &top); + hb_ot_layout_get_baseline_with_fallback (font, + HB_OT_LAYOUT_BASELINE_TAG_IDEO_EMBOX_BOTTOM_OR_LEFT, + direction, + script_tag, + language_tag, + &bottom); + *coord = (top + bottom) / 2; + + } + break; + + case HB_OT_LAYOUT_BASELINE_TAG_IDEO_FACE_CENTRAL: + { + hb_position_t top, bottom; + hb_ot_layout_get_baseline_with_fallback (font, + HB_OT_LAYOUT_BASELINE_TAG_IDEO_FACE_TOP_OR_RIGHT, + direction, + script_tag, + language_tag, + &top); + hb_ot_layout_get_baseline_with_fallback (font, + HB_OT_LAYOUT_BASELINE_TAG_IDEO_FACE_BOTTOM_OR_LEFT, + direction, + script_tag, + language_tag, + &bottom); + *coord = (top + bottom) / 2; + + } + break; + + case _HB_OT_LAYOUT_BASELINE_TAG_MAX_VALUE: + default: + *coord = 0; + break; + } +} + #endif |