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Diffstat (limited to 'gfx/harfbuzz/src/hb-ot-metrics.cc')
| -rw-r--r-- | gfx/harfbuzz/src/hb-ot-metrics.cc | 436 |
1 files changed, 436 insertions, 0 deletions
diff --git a/gfx/harfbuzz/src/hb-ot-metrics.cc b/gfx/harfbuzz/src/hb-ot-metrics.cc new file mode 100644 index 0000000000..e314d946b6 --- /dev/null +++ b/gfx/harfbuzz/src/hb-ot-metrics.cc @@ -0,0 +1,436 @@ +/* + * Copyright © 2018-2019 Ebrahim Byagowi + * + * This is part of HarfBuzz, a text shaping library. + * + * Permission is hereby granted, without written agreement and without + * license or royalty fees, to use, copy, modify, and distribute this + * software and its documentation for any purpose, provided that the + * above copyright notice and the following two paragraphs appear in + * all copies of this software. + * + * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR + * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES + * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN + * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH + * DAMAGE. + * + * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, + * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND + * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS + * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO + * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. + */ + +#include "hb.hh" + +#include "hb-ot-var-mvar-table.hh" +#include "hb-ot-gasp-table.hh" // Just so we compile it; unused otherwise. +#include "hb-ot-os2-table.hh" +#include "hb-ot-post-table.hh" +#include "hb-ot-hhea-table.hh" +#include "hb-ot-metrics.hh" +#include "hb-ot-face.hh" + + +/** + * SECTION:hb-ot-metrics + * @title: hb-ot-metrics + * @short_description: OpenType Metrics + * @include: hb-ot.h + * + * Functions for fetching metrics from fonts. + **/ + +static float +_fix_ascender_descender (float value, hb_ot_metrics_tag_t metrics_tag) +{ + if (metrics_tag == HB_OT_METRICS_TAG_HORIZONTAL_ASCENDER || + metrics_tag == HB_OT_METRICS_TAG_VERTICAL_ASCENDER) + return fabs ((double) value); + if (metrics_tag == HB_OT_METRICS_TAG_HORIZONTAL_DESCENDER || + metrics_tag == HB_OT_METRICS_TAG_VERTICAL_DESCENDER) + return -fabs ((double) value); + return value; +} + +/* The common part of _get_position logic needed on hb-ot-font and here + to be able to have slim builds without the not always needed parts */ +bool +_hb_ot_metrics_get_position_common (hb_font_t *font, + hb_ot_metrics_tag_t metrics_tag, + hb_position_t *position /* OUT. May be NULL. */) +{ + hb_face_t *face = font->face; + switch ((unsigned) metrics_tag) + { +#ifndef HB_NO_VAR +#define GET_VAR face->table.MVAR->get_var (metrics_tag, font->coords, font->num_coords) +#else +#define GET_VAR .0f +#endif +#define GET_METRIC_X(TABLE, ATTR) \ + (face->table.TABLE->has_data () && \ + ((void) (position && (*position = font->em_scalef_x (_fix_ascender_descender ( \ + face->table.TABLE->ATTR + GET_VAR, metrics_tag)))), true)) +#define GET_METRIC_Y(TABLE, ATTR) \ + (face->table.TABLE->has_data () && \ + ((void) (position && (*position = font->em_scalef_y (_fix_ascender_descender ( \ + face->table.TABLE->ATTR + GET_VAR, metrics_tag)))), true)) + + case HB_OT_METRICS_TAG_HORIZONTAL_ASCENDER: + return (face->table.OS2->use_typo_metrics () && GET_METRIC_Y (OS2, sTypoAscender)) || + GET_METRIC_Y (hhea, ascender); + case HB_OT_METRICS_TAG_HORIZONTAL_DESCENDER: + return (face->table.OS2->use_typo_metrics () && GET_METRIC_Y (OS2, sTypoDescender)) || + GET_METRIC_Y (hhea, descender); + case HB_OT_METRICS_TAG_HORIZONTAL_LINE_GAP: + return (face->table.OS2->use_typo_metrics () && GET_METRIC_Y (OS2, sTypoLineGap)) || + GET_METRIC_Y (hhea, lineGap); + +#ifndef HB_NO_VERTICAL + case HB_OT_METRICS_TAG_VERTICAL_ASCENDER: return GET_METRIC_X (vhea, ascender); + case HB_OT_METRICS_TAG_VERTICAL_DESCENDER: return GET_METRIC_X (vhea, descender); + case HB_OT_METRICS_TAG_VERTICAL_LINE_GAP: return GET_METRIC_X (vhea, lineGap); +#endif + +#undef GET_METRIC_Y +#undef GET_METRIC_X +#undef GET_VAR + default: assert (0); return false; + } +} + +#ifndef HB_NO_METRICS + +#if 0 +static bool +_get_gasp (hb_face_t *face, float *result, hb_ot_metrics_tag_t metrics_tag) +{ + const OT::GaspRange& range = face->table.gasp->get_gasp_range (metrics_tag - HB_TAG ('g','s','p','0')); + if (&range == &Null (OT::GaspRange)) return false; + if (result) *result = range.rangeMaxPPEM + font->face->table.MVAR->get_var (metrics_tag, font->coords, font->num_coords); + return true; +} +#endif + +/* Private tags for https://github.com/harfbuzz/harfbuzz/issues/1866 */ +#define _HB_OT_METRICS_TAG_HORIZONTAL_ASCENDER_OS2 HB_TAG ('O','a','s','c') +#define _HB_OT_METRICS_TAG_HORIZONTAL_ASCENDER_HHEA HB_TAG ('H','a','s','c') +#define _HB_OT_METRICS_TAG_HORIZONTAL_DESCENDER_OS2 HB_TAG ('O','d','s','c') +#define _HB_OT_METRICS_TAG_HORIZONTAL_DESCENDER_HHEA HB_TAG ('H','d','s','c') +#define _HB_OT_METRICS_TAG_HORIZONTAL_LINE_GAP_OS2 HB_TAG ('O','l','g','p') +#define _HB_OT_METRICS_TAG_HORIZONTAL_LINE_GAP_HHEA HB_TAG ('H','l','g','p') + +/** + * hb_ot_metrics_get_position: + * @font: an #hb_font_t object. + * @metrics_tag: tag of metrics value you like to fetch. + * @position: (out) (optional): result of metrics value from the font. + * + * Fetches metrics value corresponding to @metrics_tag from @font. + * + * Returns: Whether found the requested metrics in the font. + * Since: 2.6.0 + **/ +hb_bool_t +hb_ot_metrics_get_position (hb_font_t *font, + hb_ot_metrics_tag_t metrics_tag, + hb_position_t *position /* OUT. May be NULL. */) +{ + hb_face_t *face = font->face; + switch ((unsigned) metrics_tag) + { + case HB_OT_METRICS_TAG_HORIZONTAL_ASCENDER: + case HB_OT_METRICS_TAG_HORIZONTAL_DESCENDER: + case HB_OT_METRICS_TAG_HORIZONTAL_LINE_GAP: + case HB_OT_METRICS_TAG_VERTICAL_ASCENDER: + case HB_OT_METRICS_TAG_VERTICAL_DESCENDER: + case HB_OT_METRICS_TAG_VERTICAL_LINE_GAP: return _hb_ot_metrics_get_position_common (font, metrics_tag, position); +#ifndef HB_NO_VAR +#define GET_VAR hb_ot_metrics_get_variation (font, metrics_tag) +#else +#define GET_VAR 0 +#endif +#define GET_METRIC_X(TABLE, ATTR) \ + (face->table.TABLE->has_data () && \ + ((void) (position && (*position = font->em_scalef_x (face->table.TABLE->ATTR + GET_VAR))), true)) +#define GET_METRIC_Y(TABLE, ATTR) \ + (face->table.TABLE->has_data () && \ + ((void) (position && (*position = font->em_scalef_y (face->table.TABLE->ATTR + GET_VAR))), true)) + case HB_OT_METRICS_TAG_HORIZONTAL_CLIPPING_ASCENT: return GET_METRIC_Y (OS2, usWinAscent); + case HB_OT_METRICS_TAG_HORIZONTAL_CLIPPING_DESCENT: return GET_METRIC_Y (OS2, usWinDescent); + + case HB_OT_METRICS_TAG_HORIZONTAL_CARET_RISE: + case HB_OT_METRICS_TAG_HORIZONTAL_CARET_RUN: + { + unsigned mult = 1u; + + if (font->slant) + { + unsigned rise = face->table.hhea->caretSlopeRise; + unsigned upem = face->get_upem (); + mult = (rise && rise < upem) ? hb_min (upem / rise, 256u) : 1u; + } + + if (metrics_tag == HB_OT_METRICS_TAG_HORIZONTAL_CARET_RISE) + { + bool ret = GET_METRIC_Y (hhea, caretSlopeRise); + + if (position) + *position *= mult; + + return ret; + } + else + { + hb_position_t rise = 0; + + if (font->slant && position && GET_METRIC_Y (hhea, caretSlopeRise)) + rise = *position; + + bool ret = GET_METRIC_X (hhea, caretSlopeRun); + + if (position) + { + *position *= mult; + + if (font->slant) + *position += roundf (mult * font->slant_xy * rise); + } + + return ret; + } + } + case HB_OT_METRICS_TAG_HORIZONTAL_CARET_OFFSET: return GET_METRIC_X (hhea, caretOffset); + +#ifndef HB_NO_VERTICAL + case HB_OT_METRICS_TAG_VERTICAL_CARET_RISE: return GET_METRIC_X (vhea, caretSlopeRise); + case HB_OT_METRICS_TAG_VERTICAL_CARET_RUN: return GET_METRIC_Y (vhea, caretSlopeRun); + case HB_OT_METRICS_TAG_VERTICAL_CARET_OFFSET: return GET_METRIC_Y (vhea, caretOffset); +#endif + case HB_OT_METRICS_TAG_X_HEIGHT: return GET_METRIC_Y (OS2->v2 (), sxHeight); + case HB_OT_METRICS_TAG_CAP_HEIGHT: return GET_METRIC_Y (OS2->v2 (), sCapHeight); + case HB_OT_METRICS_TAG_SUBSCRIPT_EM_X_SIZE: return GET_METRIC_X (OS2, ySubscriptXSize); + case HB_OT_METRICS_TAG_SUBSCRIPT_EM_Y_SIZE: return GET_METRIC_Y (OS2, ySubscriptYSize); + case HB_OT_METRICS_TAG_SUBSCRIPT_EM_X_OFFSET: return GET_METRIC_X (OS2, ySubscriptXOffset); + case HB_OT_METRICS_TAG_SUBSCRIPT_EM_Y_OFFSET: return GET_METRIC_Y (OS2, ySubscriptYOffset); + case HB_OT_METRICS_TAG_SUPERSCRIPT_EM_X_SIZE: return GET_METRIC_X (OS2, ySuperscriptXSize); + case HB_OT_METRICS_TAG_SUPERSCRIPT_EM_Y_SIZE: return GET_METRIC_Y (OS2, ySuperscriptYSize); + case HB_OT_METRICS_TAG_SUPERSCRIPT_EM_X_OFFSET: return GET_METRIC_X (OS2, ySuperscriptXOffset); + case HB_OT_METRICS_TAG_SUPERSCRIPT_EM_Y_OFFSET: return GET_METRIC_Y (OS2, ySuperscriptYOffset); + case HB_OT_METRICS_TAG_STRIKEOUT_SIZE: return GET_METRIC_Y (OS2, yStrikeoutSize); + case HB_OT_METRICS_TAG_STRIKEOUT_OFFSET: return GET_METRIC_Y (OS2, yStrikeoutPosition); + case HB_OT_METRICS_TAG_UNDERLINE_SIZE: return GET_METRIC_Y (post->table, underlineThickness); + case HB_OT_METRICS_TAG_UNDERLINE_OFFSET: return GET_METRIC_Y (post->table, underlinePosition); + + /* Private tags */ + case _HB_OT_METRICS_TAG_HORIZONTAL_ASCENDER_OS2: return GET_METRIC_Y (OS2, sTypoAscender); + case _HB_OT_METRICS_TAG_HORIZONTAL_ASCENDER_HHEA: return GET_METRIC_Y (hhea, ascender); + case _HB_OT_METRICS_TAG_HORIZONTAL_DESCENDER_OS2: return GET_METRIC_Y (OS2, sTypoDescender); + case _HB_OT_METRICS_TAG_HORIZONTAL_DESCENDER_HHEA: return GET_METRIC_Y (hhea, descender); + case _HB_OT_METRICS_TAG_HORIZONTAL_LINE_GAP_OS2: return GET_METRIC_Y (OS2, sTypoLineGap); + case _HB_OT_METRICS_TAG_HORIZONTAL_LINE_GAP_HHEA: return GET_METRIC_Y (hhea, lineGap); +#undef GET_METRIC_Y +#undef GET_METRIC_X +#undef GET_VAR + default: return false; + } +} + +/** + * hb_ot_metrics_get_position_with_fallback: + * @font: an #hb_font_t object. + * @metrics_tag: tag of metrics value you like to fetch. + * @position: (out) (optional): result of metrics value from the font. + * + * Fetches metrics value corresponding to @metrics_tag from @font, + * and synthesizes a value if it the value is missing in the font. + * + * Since: 4.0.0 + **/ +void +hb_ot_metrics_get_position_with_fallback (hb_font_t *font, + hb_ot_metrics_tag_t metrics_tag, + hb_position_t *position /* OUT */) +{ + hb_font_extents_t font_extents; + hb_codepoint_t glyph; + hb_glyph_extents_t extents; + + if (hb_ot_metrics_get_position (font, metrics_tag, position)) + { + if ((metrics_tag != HB_OT_METRICS_TAG_STRIKEOUT_SIZE && + metrics_tag != HB_OT_METRICS_TAG_UNDERLINE_SIZE) || + *position != 0) + return; + } + + switch (metrics_tag) + { + case HB_OT_METRICS_TAG_HORIZONTAL_ASCENDER: + case HB_OT_METRICS_TAG_HORIZONTAL_CLIPPING_ASCENT: + hb_font_get_extents_for_direction (font, HB_DIRECTION_LTR, &font_extents); + *position = font_extents.ascender; + break; + + case HB_OT_METRICS_TAG_VERTICAL_ASCENDER: + hb_font_get_extents_for_direction (font, HB_DIRECTION_TTB, &font_extents); + *position = font_extents.ascender; + break; + + case HB_OT_METRICS_TAG_HORIZONTAL_DESCENDER: + case HB_OT_METRICS_TAG_HORIZONTAL_CLIPPING_DESCENT: + hb_font_get_extents_for_direction (font, HB_DIRECTION_LTR, &font_extents); + *position = font_extents.descender; + break; + + case HB_OT_METRICS_TAG_VERTICAL_DESCENDER: + hb_font_get_extents_for_direction (font, HB_DIRECTION_TTB, &font_extents); + *position = font_extents.ascender; + break; + + case HB_OT_METRICS_TAG_HORIZONTAL_LINE_GAP: + hb_font_get_extents_for_direction (font, HB_DIRECTION_LTR, &font_extents); + *position = font_extents.line_gap; + break; + + case HB_OT_METRICS_TAG_VERTICAL_LINE_GAP: + hb_font_get_extents_for_direction (font, HB_DIRECTION_TTB, &font_extents); + *position = font_extents.line_gap; + break; + + case HB_OT_METRICS_TAG_HORIZONTAL_CARET_RISE: + case HB_OT_METRICS_TAG_VERTICAL_CARET_RISE: + *position = 1; + break; + + case HB_OT_METRICS_TAG_HORIZONTAL_CARET_RUN: + case HB_OT_METRICS_TAG_VERTICAL_CARET_RUN: + *position = 0; + break; + + case HB_OT_METRICS_TAG_HORIZONTAL_CARET_OFFSET: + case HB_OT_METRICS_TAG_VERTICAL_CARET_OFFSET: + *position = 0; + break; + + case HB_OT_METRICS_TAG_X_HEIGHT: + if (hb_font_get_nominal_glyph (font, 'x', &glyph) && + hb_font_get_glyph_extents (font, glyph, &extents)) + *position = extents.y_bearing; + else + *position = font->y_scale / 2; + break; + + case HB_OT_METRICS_TAG_CAP_HEIGHT: + if (hb_font_get_nominal_glyph (font, 'O', &glyph) && + hb_font_get_glyph_extents (font, glyph, &extents)) + *position = extents.height + 2 * extents.y_bearing; + else + *position = font->y_scale * 2 / 3; + break; + + case HB_OT_METRICS_TAG_STRIKEOUT_SIZE: + case HB_OT_METRICS_TAG_UNDERLINE_SIZE: + *position = font->y_scale / 18; + break; + + case HB_OT_METRICS_TAG_STRIKEOUT_OFFSET: + { + hb_position_t ascender; + hb_ot_metrics_get_position_with_fallback (font, + HB_OT_METRICS_TAG_HORIZONTAL_ASCENDER, + &ascender); + *position = ascender / 2; + } + break; + + case HB_OT_METRICS_TAG_UNDERLINE_OFFSET: + *position = - font->y_scale / 18; + break; + + case HB_OT_METRICS_TAG_SUBSCRIPT_EM_X_SIZE: + case HB_OT_METRICS_TAG_SUPERSCRIPT_EM_X_SIZE: + *position = font->x_scale * 10 / 12; + break; + + case HB_OT_METRICS_TAG_SUBSCRIPT_EM_Y_SIZE: + case HB_OT_METRICS_TAG_SUPERSCRIPT_EM_Y_SIZE: + *position = font->y_scale * 10 / 12; + break; + + case HB_OT_METRICS_TAG_SUBSCRIPT_EM_X_OFFSET: + case HB_OT_METRICS_TAG_SUPERSCRIPT_EM_X_OFFSET: + *position = 0; + break; + + case HB_OT_METRICS_TAG_SUBSCRIPT_EM_Y_OFFSET: + case HB_OT_METRICS_TAG_SUPERSCRIPT_EM_Y_OFFSET: + *position = font->y_scale / 5; + break; + + case _HB_OT_METRICS_TAG_MAX_VALUE: + default: + *position = 0; + break; + } +} + +#ifndef HB_NO_VAR +/** + * hb_ot_metrics_get_variation: + * @font: an #hb_font_t object. + * @metrics_tag: tag of metrics value you like to fetch. + * + * Fetches metrics value corresponding to @metrics_tag from @font with the + * current font variation settings applied. + * + * Returns: The requested metric value. + * + * Since: 2.6.0 + **/ +float +hb_ot_metrics_get_variation (hb_font_t *font, hb_ot_metrics_tag_t metrics_tag) +{ + return font->face->table.MVAR->get_var (metrics_tag, font->coords, font->num_coords); +} + +/** + * hb_ot_metrics_get_x_variation: + * @font: an #hb_font_t object. + * @metrics_tag: tag of metrics value you like to fetch. + * + * Fetches horizontal metrics value corresponding to @metrics_tag from @font + * with the current font variation settings applied. + * + * Returns: The requested metric value. + * + * Since: 2.6.0 + **/ +hb_position_t +hb_ot_metrics_get_x_variation (hb_font_t *font, hb_ot_metrics_tag_t metrics_tag) +{ + return font->em_scalef_x (hb_ot_metrics_get_variation (font, metrics_tag)); +} + +/** + * hb_ot_metrics_get_y_variation: + * @font: an #hb_font_t object. + * @metrics_tag: tag of metrics value you like to fetch. + * + * Fetches vertical metrics value corresponding to @metrics_tag from @font with + * the current font variation settings applied. + * + * Returns: The requested metric value. + * + * Since: 2.6.0 + **/ +hb_position_t +hb_ot_metrics_get_y_variation (hb_font_t *font, hb_ot_metrics_tag_t metrics_tag) +{ + return font->em_scalef_y (hb_ot_metrics_get_variation (font, metrics_tag)); +} +#endif + +#endif |