/work/workdir/UnpackedTarball/harfbuzz/src/hb-ot-metrics.cc

Source
/*
 * 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
// Unused:
//#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))
#define GET_HEA_METRIC_X(TABLE, ATTR) \
  (face->table.TABLE->has_data () && \
    ((void) (position && (*position = font->em_scalef_x (_fix_ascender_descender ( \
      HB_DUAL_GET (*face->table.TABLE, table->ATTR) + GET_VAR, metrics_tag)))), true))
#define GET_HEA_METRIC_Y(TABLE, ATTR) \
  (face->table.TABLE->has_data () && \
    ((void) (position && (*position = font->em_scalef_y (_fix_ascender_descender ( \
      HB_DUAL_GET (*face->table.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_HEA_METRIC_Y (hhea, ascender);
  case HB_OT_METRICS_TAG_HORIZONTAL_DESCENDER:
    return (face->table.OS2->use_typo_metrics () && GET_METRIC_Y (OS2, sTypoDescender)) ||
     GET_HEA_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_HEA_METRIC_Y (hhea, lineGap);

#ifndef HB_NO_VERTICAL
  case HB_OT_METRICS_TAG_VERTICAL_ASCENDER:  return GET_HEA_METRIC_X (vhea, ascender);
  case HB_OT_METRICS_TAG_VERTICAL_DESCENDER: return GET_HEA_METRIC_X (vhea, descender);
  case HB_OT_METRICS_TAG_VERTICAL_LINE_GAP:  return GET_HEA_METRIC_X (vhea, lineGap);
#endif

#undef GET_HEA_METRIC_Y
#undef GET_HEA_METRIC_X
#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))
#define GET_HEA_METRIC_X(TABLE, ATTR) \
  (face->table.TABLE->has_data () && \
    ((void) (position && (*position = font->em_scalef_x (HB_DUAL_GET (*face->table.TABLE, table->ATTR) + GET_VAR))), true))
#define GET_HEA_METRIC_Y(TABLE, ATTR) \
  (face->table.TABLE->has_data () && \
    ((void) (position && (*position = font->em_scalef_y (HB_DUAL_GET (*face->table.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 = HB_DUAL_GET (*face->table.hhea, table->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_HEA_METRIC_Y (hhea, caretSlopeRise);

      if (position)
  *position = hb_clamp_to<hb_position_t> ((int64_t) *position * mult);

      return ret;
    }
    else
    {
      hb_position_t rise = 0;

      if (font->slant && position && GET_HEA_METRIC_Y (hhea, caretSlopeRise))
  rise = *position;

      bool ret = GET_HEA_METRIC_X (hhea, caretSlopeRun);

      if (position)
      {
  *position = hb_clamp_to<hb_position_t> ((int64_t) *position * mult);

  if (font->slant)
    *position = hb_saturate_add (*position,
               hb_clamp_to<hb_position_t> (roundf (mult * font->slant_xy * rise)));
      }

      return ret;
    }
  }
  case HB_OT_METRICS_TAG_HORIZONTAL_CARET_OFFSET:     return GET_HEA_METRIC_X (hhea, caretOffset);

#ifndef HB_NO_VERTICAL
  case HB_OT_METRICS_TAG_VERTICAL_CARET_RISE:         return GET_HEA_METRIC_X (vhea, caretSlopeRise);
  case HB_OT_METRICS_TAG_VERTICAL_CARET_RUN:          return GET_HEA_METRIC_Y (vhea, caretSlopeRun);
  case HB_OT_METRICS_TAG_VERTICAL_CARET_OFFSET:       return GET_HEA_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_HEA_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_HEA_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_HEA_METRIC_Y (hhea, lineGap);
#undef GET_HEA_METRIC_Y
#undef GET_HEA_METRIC_X
#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 = hb_clamp_to<hb_position_t> ((int64_t) extents.height +
                2 * (int64_t) extents.y_bearing);
    else
      *position = hb_clamp_to<hb_position_t> ((int64_t) 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 = hb_saturate_neg (font->y_scale) / 18;
    break;

  case HB_OT_METRICS_TAG_SUBSCRIPT_EM_X_SIZE:
  case HB_OT_METRICS_TAG_SUPERSCRIPT_EM_X_SIZE:
    *position = hb_clamp_to<hb_position_t> ((int64_t) 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 = hb_clamp_to<hb_position_t> ((int64_t) 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

Coverage Report

Created: 2026-10-14 09:33

Line	Count	Source
1		/*
2		* Copyright © 2018-2019 Ebrahim Byagowi
3		*
4		* This is part of HarfBuzz, a text shaping library.
5		*
6		* Permission is hereby granted, without written agreement and without
7		* license or royalty fees, to use, copy, modify, and distribute this
8		* software and its documentation for any purpose, provided that the
9		* above copyright notice and the following two paragraphs appear in
10		* all copies of this software.
11		*
12		* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
13		* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
14		* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
15		* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
16		* DAMAGE.
17		*
18		* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
19		* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20		* FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
21		* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
22		* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
23		*/
24
25		#include "hb.hh"
26
27		#include "hb-ot-var-mvar-table.hh"
28		#include "hb-ot-gasp-table.hh" // Just so we compile it; unused otherwise.
29		#include "hb-ot-os2-table.hh"
30		#include "hb-ot-post-table.hh"
31		#include "hb-ot-hhea-table.hh"
32		#include "hb-ot-metrics.hh"
33		#include "hb-ot-face.hh"
34
35
36		/**
37		* SECTION:hb-ot-metrics
38		* @title: hb-ot-metrics
39		* @short_description: OpenType Metrics
40		* @include: hb-ot.h
41		*
42		* Functions for fetching metrics from fonts.
43		**/
44
45		static float
46		_fix_ascender_descender (float value, hb_ot_metrics_tag_t metrics_tag)
47	1.66M	{
48	1.66M	if (metrics_tag == HB_OT_METRICS_TAG_HORIZONTAL_ASCENDER \|\|
49	1.11M	metrics_tag == HB_OT_METRICS_TAG_VERTICAL_ASCENDER)
50	555k	return fabs ((double) value);
51	1.11M	if (metrics_tag == HB_OT_METRICS_TAG_HORIZONTAL_DESCENDER \|\|
52	555k	metrics_tag == HB_OT_METRICS_TAG_VERTICAL_DESCENDER)
53	555k	return -fabs ((double) value);
54	555k	return value;
55	1.11M	}
56
57		/* The common part of _get_position logic needed on hb-ot-font and here
58		to be able to have slim builds without the not always needed parts */
59		bool
60		_hb_ot_metrics_get_position_common (hb_font_t *font,
61		hb_ot_metrics_tag_t metrics_tag,
62		hb_position_t position / OUT. May be NULL. */)
63	1.66M	{
64	1.66M	hb_face_t *face = font->face;
65	1.66M	switch ((unsigned) metrics_tag)
66	1.66M	{
67	0	#ifndef HB_NO_VAR
68	1.66M	#define GET_VAR face->table.MVAR->get_var (metrics_tag, font->coords, font->num_coords)
69		#else
70		#define GET_VAR .0f
71		#endif
72		// Unused:
73		//#define GET_METRIC_X(TABLE, ATTR) \
74		// (face->table.TABLE->has_data () && \
75		// ((void) (position && (*position = font->em_scalef_x (_fix_ascender_descender ( \
76		// face->table.TABLE->ATTR + GET_VAR, metrics_tag)))), true))
77	0	#define GET_METRIC_Y(TABLE, ATTR) \
78	0	(face->table.TABLE->has_data () && \
79	0	((void) (position && (*position = font->em_scalef_y (_fix_ascender_descender ( \
80	0	face->table.TABLE->ATTR + GET_VAR, metrics_tag)))), true))
81	0	#define GET_HEA_METRIC_X(TABLE, ATTR) \
82	0	(face->table.TABLE->has_data () && \
83	0	((void) (position && (*position = font->em_scalef_x (_fix_ascender_descender ( \
84	0	HB_DUAL_GET (*face->table.TABLE, table->ATTR) + GET_VAR, metrics_tag)))), true))
85	0	#define GET_HEA_METRIC_Y(TABLE, ATTR) \
86	1.66M	(face->table.TABLE->has_data () && \
87	1.66M	((void) (position && (*position = font->em_scalef_y (_fix_ascender_descender ( \
88	1.66M	HB_DUAL_GET (*face->table.TABLE, table->ATTR) + GET_VAR, metrics_tag)))), true))
89
90	555k	case HB_OT_METRICS_TAG_HORIZONTAL_ASCENDER:
91	555k	return (face->table.OS2->use_typo_metrics () && GET_METRIC_Y (OS2, sTypoAscender)) \|\|
92	555k	GET_HEA_METRIC_Y (hhea, ascender);
93	555k	case HB_OT_METRICS_TAG_HORIZONTAL_DESCENDER:
94	555k	return (face->table.OS2->use_typo_metrics () && GET_METRIC_Y (OS2, sTypoDescender)) \|\|
95	555k	GET_HEA_METRIC_Y (hhea, descender);
96	555k	case HB_OT_METRICS_TAG_HORIZONTAL_LINE_GAP:
97	555k	return (face->table.OS2->use_typo_metrics () && GET_METRIC_Y (OS2, sTypoLineGap)) \|\|
98	555k	GET_HEA_METRIC_Y (hhea, lineGap);
99
100	0	#ifndef HB_NO_VERTICAL
101	0	case HB_OT_METRICS_TAG_VERTICAL_ASCENDER: return GET_HEA_METRIC_X (vhea, ascender);
102	0	case HB_OT_METRICS_TAG_VERTICAL_DESCENDER: return GET_HEA_METRIC_X (vhea, descender);
103	0	case HB_OT_METRICS_TAG_VERTICAL_LINE_GAP: return GET_HEA_METRIC_X (vhea, lineGap);
104	0	#endif
105
106	0	#undef GET_HEA_METRIC_Y
107	0	#undef GET_HEA_METRIC_X
108	0	#undef GET_METRIC_Y
109	0	#undef GET_METRIC_X
110	0	#undef GET_VAR
111	0	default: assert (0); return false;
112	1.66M	}
113	1.66M	}
114
115		#ifndef HB_NO_METRICS
116
117		#if 0
118		static bool
119		_get_gasp (hb_face_t face, float result, hb_ot_metrics_tag_t metrics_tag)
120		{
121		const OT::GaspRange& range = face->table.gasp->get_gasp_range (metrics_tag - HB_TAG ('g','s','p','0'));
122		if (&range == &Null (OT::GaspRange)) return false;
123		if (result) *result = range.rangeMaxPPEM + font->face->table.MVAR->get_var (metrics_tag, font->coords, font->num_coords);
124		return true;
125		}
126		#endif
127
128		/* Private tags for https://github.com/harfbuzz/harfbuzz/issues/1866 */
129	161k	#define _HB_OT_METRICS_TAG_HORIZONTAL_ASCENDER_OS2 HB_TAG ('O','a','s','c')
130	178k	#define _HB_OT_METRICS_TAG_HORIZONTAL_ASCENDER_HHEA HB_TAG ('H','a','s','c')
131	161k	#define _HB_OT_METRICS_TAG_HORIZONTAL_DESCENDER_OS2 HB_TAG ('O','d','s','c')
132	178k	#define _HB_OT_METRICS_TAG_HORIZONTAL_DESCENDER_HHEA HB_TAG ('H','d','s','c')
133	161k	#define _HB_OT_METRICS_TAG_HORIZONTAL_LINE_GAP_OS2 HB_TAG ('O','l','g','p')
134	161k	#define _HB_OT_METRICS_TAG_HORIZONTAL_LINE_GAP_HHEA HB_TAG ('H','l','g','p')
135
136		/**
137		* hb_ot_metrics_get_position:
138		* @font: an #hb_font_t object.
139		* @metrics_tag: tag of metrics value you like to fetch.
140		* @position: (out) (optional): result of metrics value from the font.
141		*
142		* Fetches metrics value corresponding to @metrics_tag from @font.
143		*
144		* Returns: Whether found the requested metrics in the font.
145		* Since: 2.6.0
146		**/
147		hb_bool_t
148		hb_ot_metrics_get_position (hb_font_t *font,
149		hb_ot_metrics_tag_t metrics_tag,
150		hb_position_t position / OUT. May be NULL. */)
151	2.63M	{
152	2.63M	hb_face_t *face = font->face;
153	2.63M	switch ((unsigned) metrics_tag)
154	2.63M	{
155	0	case HB_OT_METRICS_TAG_HORIZONTAL_ASCENDER:
156	0	case HB_OT_METRICS_TAG_HORIZONTAL_DESCENDER:
157	0	case HB_OT_METRICS_TAG_HORIZONTAL_LINE_GAP:
158	0	case HB_OT_METRICS_TAG_VERTICAL_ASCENDER:
159	0	case HB_OT_METRICS_TAG_VERTICAL_DESCENDER:
160	0	case HB_OT_METRICS_TAG_VERTICAL_LINE_GAP: return _hb_ot_metrics_get_position_common (font, metrics_tag, position);
161	0	#ifndef HB_NO_VAR
162	2.63M	#define GET_VAR hb_ot_metrics_get_variation (font, metrics_tag)
163		#else
164		#define GET_VAR 0
165		#endif
166	0	#define GET_METRIC_X(TABLE, ATTR) \
167	0	(face->table.TABLE->has_data () && \
168	0	((void) (position && (*position = font->em_scalef_x (face->table.TABLE->ATTR + GET_VAR))), true))
169	0	#define GET_METRIC_Y(TABLE, ATTR) \
170	2.12M	(face->table.TABLE->has_data () && \
171	2.12M	((void) (position && (*position = font->em_scalef_y (face->table.TABLE->ATTR + GET_VAR))), true))
172	0	#define GET_HEA_METRIC_X(TABLE, ATTR) \
173	0	(face->table.TABLE->has_data () && \
174	0	((void) (position && (position = font->em_scalef_x (HB_DUAL_GET (face->table.TABLE, table->ATTR) + GET_VAR))), true))
175	0	#define GET_HEA_METRIC_Y(TABLE, ATTR) \
176	518k	(face->table.TABLE->has_data () && \
177	518k	((void) (position && (position = font->em_scalef_y (HB_DUAL_GET (face->table.TABLE, table->ATTR) + GET_VAR))), true))
178	161k	case HB_OT_METRICS_TAG_HORIZONTAL_CLIPPING_ASCENT: return GET_METRIC_Y (OS2, usWinAscent);
179	161k	case HB_OT_METRICS_TAG_HORIZONTAL_CLIPPING_DESCENT: return GET_METRIC_Y (OS2, usWinDescent);
180
181	0	case HB_OT_METRICS_TAG_HORIZONTAL_CARET_RISE:
182	0	case HB_OT_METRICS_TAG_HORIZONTAL_CARET_RUN:
183	0	{
184	0	unsigned mult = 1u;
185
186	0	if (font->slant)
187	0	{
188	0	unsigned rise = HB_DUAL_GET (*face->table.hhea, table->caretSlopeRise);
189	0	unsigned upem = face->get_upem ();
190	0	mult = (rise && rise < upem) ? hb_min (upem / rise, 256u) : 1u;
191	0	}
192
193	0	if (metrics_tag == HB_OT_METRICS_TAG_HORIZONTAL_CARET_RISE)
194	0	{
195	0	bool ret = GET_HEA_METRIC_Y (hhea, caretSlopeRise);
196
197	0	if (position)
198	0	position = hb_clamp_to<hb_position_t> ((int64_t) position * mult);
199
200	0	return ret;
201	0	}
202	0	else
203	0	{
204	0	hb_position_t rise = 0;
205
206	0	if (font->slant && position && GET_HEA_METRIC_Y (hhea, caretSlopeRise))
207	0	rise = *position;
208
209	0	bool ret = GET_HEA_METRIC_X (hhea, caretSlopeRun);
210
211	0	if (position)
212	0	{
213	0	position = hb_clamp_to<hb_position_t> ((int64_t) position * mult);
214
215	0	if (font->slant)
216	0	position = hb_saturate_add (position,
217	0	hb_clamp_to<hb_position_t> (roundf (mult * font->slant_xy * rise)));
218	0	}
219
220	0	return ret;
221	0	}
222	0	}
223	0	case HB_OT_METRICS_TAG_HORIZONTAL_CARET_OFFSET: return GET_HEA_METRIC_X (hhea, caretOffset);
224
225	0	#ifndef HB_NO_VERTICAL
226	0	case HB_OT_METRICS_TAG_VERTICAL_CARET_RISE: return GET_HEA_METRIC_X (vhea, caretSlopeRise);
227	0	case HB_OT_METRICS_TAG_VERTICAL_CARET_RUN: return GET_HEA_METRIC_Y (vhea, caretSlopeRun);
228	0	case HB_OT_METRICS_TAG_VERTICAL_CARET_OFFSET: return GET_HEA_METRIC_Y (vhea, caretOffset);
229	0	#endif
230	0	case HB_OT_METRICS_TAG_X_HEIGHT: return GET_METRIC_Y (OS2->v2 (), sxHeight);
231	16.3k	case HB_OT_METRICS_TAG_CAP_HEIGHT: return GET_METRIC_Y (OS2->v2 (), sCapHeight);
232	0	case HB_OT_METRICS_TAG_SUBSCRIPT_EM_X_SIZE: return GET_METRIC_X (OS2, ySubscriptXSize);
233	0	case HB_OT_METRICS_TAG_SUBSCRIPT_EM_Y_SIZE: return GET_METRIC_Y (OS2, ySubscriptYSize);
234	0	case HB_OT_METRICS_TAG_SUBSCRIPT_EM_X_OFFSET: return GET_METRIC_X (OS2, ySubscriptXOffset);
235	0	case HB_OT_METRICS_TAG_SUBSCRIPT_EM_Y_OFFSET: return GET_METRIC_Y (OS2, ySubscriptYOffset);
236	0	case HB_OT_METRICS_TAG_SUPERSCRIPT_EM_X_SIZE: return GET_METRIC_X (OS2, ySuperscriptXSize);
237	0	case HB_OT_METRICS_TAG_SUPERSCRIPT_EM_Y_SIZE: return GET_METRIC_Y (OS2, ySuperscriptYSize);
238	0	case HB_OT_METRICS_TAG_SUPERSCRIPT_EM_X_OFFSET: return GET_METRIC_X (OS2, ySuperscriptXOffset);
239	0	case HB_OT_METRICS_TAG_SUPERSCRIPT_EM_Y_OFFSET: return GET_METRIC_Y (OS2, ySuperscriptYOffset);
240	323k	case HB_OT_METRICS_TAG_STRIKEOUT_SIZE: return GET_METRIC_Y (OS2, yStrikeoutSize);
241	323k	case HB_OT_METRICS_TAG_STRIKEOUT_OFFSET: return GET_METRIC_Y (OS2, yStrikeoutPosition);
242	323k	case HB_OT_METRICS_TAG_UNDERLINE_SIZE: return GET_METRIC_Y (post->table, underlineThickness);
243	323k	case HB_OT_METRICS_TAG_UNDERLINE_OFFSET: return GET_METRIC_Y (post->table, underlinePosition);
244
245		/* Private tags */
246	161k	case _HB_OT_METRICS_TAG_HORIZONTAL_ASCENDER_OS2: return GET_METRIC_Y (OS2, sTypoAscender);
247	178k	case _HB_OT_METRICS_TAG_HORIZONTAL_ASCENDER_HHEA: return GET_HEA_METRIC_Y (hhea, ascender);
248	161k	case _HB_OT_METRICS_TAG_HORIZONTAL_DESCENDER_OS2: return GET_METRIC_Y (OS2, sTypoDescender);
249	178k	case _HB_OT_METRICS_TAG_HORIZONTAL_DESCENDER_HHEA: return GET_HEA_METRIC_Y (hhea, descender);
250	161k	case _HB_OT_METRICS_TAG_HORIZONTAL_LINE_GAP_OS2: return GET_METRIC_Y (OS2, sTypoLineGap);
251	161k	case _HB_OT_METRICS_TAG_HORIZONTAL_LINE_GAP_HHEA: return GET_HEA_METRIC_Y (hhea, lineGap);
252	0	#undef GET_HEA_METRIC_Y
253	0	#undef GET_HEA_METRIC_X
254	0	#undef GET_METRIC_Y
255	0	#undef GET_METRIC_X
256	0	#undef GET_VAR
257	0	default: return false;
258	2.63M	}
259	2.63M	}
260
261		/**
262		* hb_ot_metrics_get_position_with_fallback:
263		* @font: an #hb_font_t object.
264		* @metrics_tag: tag of metrics value you like to fetch.
265		* @position: (out) (optional): result of metrics value from the font.
266		*
267		* Fetches metrics value corresponding to @metrics_tag from @font,
268		* and synthesizes a value if it the value is missing in the font.
269		*
270		* Since: 4.0.0
271		**/
272		void
273		hb_ot_metrics_get_position_with_fallback (hb_font_t *font,
274		hb_ot_metrics_tag_t metrics_tag,
275		hb_position_t position / OUT */)
276	0	{
277	0	hb_font_extents_t font_extents;
278	0	hb_codepoint_t glyph;
279	0	hb_glyph_extents_t extents;
280
281	0	if (hb_ot_metrics_get_position (font, metrics_tag, position))
282	0	{
283	0	if ((metrics_tag != HB_OT_METRICS_TAG_STRIKEOUT_SIZE &&
284	0	metrics_tag != HB_OT_METRICS_TAG_UNDERLINE_SIZE) \|\|
285	0	*position != 0)
286	0	return;
287	0	}
288
289	0	switch (metrics_tag)
290	0	{
291	0	case HB_OT_METRICS_TAG_HORIZONTAL_ASCENDER:
292	0	case HB_OT_METRICS_TAG_HORIZONTAL_CLIPPING_ASCENT:
293	0	hb_font_get_extents_for_direction (font, HB_DIRECTION_LTR, &font_extents);
294	0	*position = font_extents.ascender;
295	0	break;
296
297	0	case HB_OT_METRICS_TAG_VERTICAL_ASCENDER:
298	0	hb_font_get_extents_for_direction (font, HB_DIRECTION_TTB, &font_extents);
299	0	*position = font_extents.ascender;
300	0	break;
301
302	0	case HB_OT_METRICS_TAG_HORIZONTAL_DESCENDER:
303	0	case HB_OT_METRICS_TAG_HORIZONTAL_CLIPPING_DESCENT:
304	0	hb_font_get_extents_for_direction (font, HB_DIRECTION_LTR, &font_extents);
305	0	*position = font_extents.descender;
306	0	break;
307
308	0	case HB_OT_METRICS_TAG_VERTICAL_DESCENDER:
309	0	hb_font_get_extents_for_direction (font, HB_DIRECTION_TTB, &font_extents);
310	0	*position = font_extents.ascender;
311	0	break;
312
313	0	case HB_OT_METRICS_TAG_HORIZONTAL_LINE_GAP:
314	0	hb_font_get_extents_for_direction (font, HB_DIRECTION_LTR, &font_extents);
315	0	*position = font_extents.line_gap;
316	0	break;
317
318	0	case HB_OT_METRICS_TAG_VERTICAL_LINE_GAP:
319	0	hb_font_get_extents_for_direction (font, HB_DIRECTION_TTB, &font_extents);
320	0	*position = font_extents.line_gap;
321	0	break;
322
323	0	case HB_OT_METRICS_TAG_HORIZONTAL_CARET_RISE:
324	0	case HB_OT_METRICS_TAG_VERTICAL_CARET_RISE:
325	0	*position = 1;
326	0	break;
327
328	0	case HB_OT_METRICS_TAG_HORIZONTAL_CARET_RUN:
329	0	case HB_OT_METRICS_TAG_VERTICAL_CARET_RUN:
330	0	*position = 0;
331	0	break;
332
333	0	case HB_OT_METRICS_TAG_HORIZONTAL_CARET_OFFSET:
334	0	case HB_OT_METRICS_TAG_VERTICAL_CARET_OFFSET:
335	0	*position = 0;
336	0	break;
337
338	0	case HB_OT_METRICS_TAG_X_HEIGHT:
339	0	if (hb_font_get_nominal_glyph (font, 'x', &glyph) &&
340	0	hb_font_get_glyph_extents (font, glyph, &extents))
341	0	*position = extents.y_bearing;
342	0	else
343	0	*position = font->y_scale / 2;
344	0	break;
345
346	0	case HB_OT_METRICS_TAG_CAP_HEIGHT:
347	0	if (hb_font_get_nominal_glyph (font, 'O', &glyph) &&
348	0	hb_font_get_glyph_extents (font, glyph, &extents))
349	0	*position = hb_clamp_to<hb_position_t> ((int64_t) extents.height +
350	0	2 * (int64_t) extents.y_bearing);
351	0	else
352	0	position = hb_clamp_to<hb_position_t> ((int64_t) font->y_scale 2 / 3);
353	0	break;
354
355	0	case HB_OT_METRICS_TAG_STRIKEOUT_SIZE:
356	0	case HB_OT_METRICS_TAG_UNDERLINE_SIZE:
357	0	*position = font->y_scale / 18;
358	0	break;
359
360	0	case HB_OT_METRICS_TAG_STRIKEOUT_OFFSET:
361	0	{
362	0	hb_position_t ascender;
363	0	hb_ot_metrics_get_position_with_fallback (font,
364	0	HB_OT_METRICS_TAG_HORIZONTAL_ASCENDER,
365	0	&ascender);
366	0	*position = ascender / 2;
367	0	}
368	0	break;
369
370	0	case HB_OT_METRICS_TAG_UNDERLINE_OFFSET:
371	0	*position = hb_saturate_neg (font->y_scale) / 18;
372	0	break;
373
374	0	case HB_OT_METRICS_TAG_SUBSCRIPT_EM_X_SIZE:
375	0	case HB_OT_METRICS_TAG_SUPERSCRIPT_EM_X_SIZE:
376	0	position = hb_clamp_to<hb_position_t> ((int64_t) font->x_scale 10 / 12);
377	0	break;
378
379	0	case HB_OT_METRICS_TAG_SUBSCRIPT_EM_Y_SIZE:
380	0	case HB_OT_METRICS_TAG_SUPERSCRIPT_EM_Y_SIZE:
381	0	position = hb_clamp_to<hb_position_t> ((int64_t) font->y_scale 10 / 12);
382	0	break;
383
384	0	case HB_OT_METRICS_TAG_SUBSCRIPT_EM_X_OFFSET:
385	0	case HB_OT_METRICS_TAG_SUPERSCRIPT_EM_X_OFFSET:
386	0	*position = 0;
387	0	break;
388
389	0	case HB_OT_METRICS_TAG_SUBSCRIPT_EM_Y_OFFSET:
390	0	case HB_OT_METRICS_TAG_SUPERSCRIPT_EM_Y_OFFSET:
391	0	*position = font->y_scale / 5;
392	0	break;
393
394	0	case _HB_OT_METRICS_TAG_MAX_VALUE:
395	0	default:
396	0	*position = 0;
397	0	break;
398	0	}
399	0	}
400
401		#ifndef HB_NO_VAR
402		/**
403		* hb_ot_metrics_get_variation:
404		* @font: an #hb_font_t object.
405		* @metrics_tag: tag of metrics value you like to fetch.
406		*
407		* Fetches metrics value corresponding to @metrics_tag from @font with the
408		* current font variation settings applied.
409		*
410		* Returns: The requested metric value.
411		*
412		* Since: 2.6.0
413		**/
414		float
415		hb_ot_metrics_get_variation (hb_font_t *font, hb_ot_metrics_tag_t metrics_tag)
416	2.63M	{
417	2.63M	return font->face->table.MVAR->get_var (metrics_tag, font->coords, font->num_coords);
418	2.63M	}
419
420		/**
421		* hb_ot_metrics_get_x_variation:
422		* @font: an #hb_font_t object.
423		* @metrics_tag: tag of metrics value you like to fetch.
424		*
425		* Fetches horizontal metrics value corresponding to @metrics_tag from @font
426		* with the current font variation settings applied.
427		*
428		* Returns: The requested metric value.
429		*
430		* Since: 2.6.0
431		**/
432		hb_position_t
433		hb_ot_metrics_get_x_variation (hb_font_t *font, hb_ot_metrics_tag_t metrics_tag)
434	0	{
435	0	return font->em_scalef_x (hb_ot_metrics_get_variation (font, metrics_tag));
436	0	}
437
438		/**
439		* hb_ot_metrics_get_y_variation:
440		* @font: an #hb_font_t object.
441		* @metrics_tag: tag of metrics value you like to fetch.
442		*
443		* Fetches vertical metrics value corresponding to @metrics_tag from @font with
444		* the current font variation settings applied.
445		*
446		* Returns: The requested metric value.
447		*
448		* Since: 2.6.0
449		**/
450		hb_position_t
451		hb_ot_metrics_get_y_variation (hb_font_t *font, hb_ot_metrics_tag_t metrics_tag)
452	0	{
453	0	return font->em_scalef_y (hb_ot_metrics_get_variation (font, metrics_tag));
454	0	}
455		#endif
456
457		#endif