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+/*
+ * 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