Roll HarfBuzz to 0.9.32

third_party/harfbuzz-ng/src/hb-ot-font.cc

+/*
+ * Copyright © 2011,2014  Google, Inc.
+ *
+ *  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.
+ *
+ * Google Author(s): Behdad Esfahbod, Roozbeh Pournader
+ */
+
+
+#include "hb-font-private.hh"
+
+#include "hb-ot-cmap-table.hh"
+#include "hb-ot-hhea-table.hh"
+#include "hb-ot-hmtx-table.hh"
+
+#include "hb-ot.h"
+
+#include "hb-private.hh"
+
+
+struct hb_ot_font_t
+{
+  unsigned int num_glyphs;
+  unsigned int num_hmetrics;
+  const OT::hmtx *hmtx;
+  hb_blob_t *hmtx_blob;
+
+  const OT::CmapSubtable *cmap;
+  const OT::CmapSubtable *cmap_uvs;
+  hb_blob_t *cmap_blob;
+};
+
+
+static hb_ot_font_t *
+_hb_ot_font_create (hb_font_t *font)
+{
+  hb_ot_font_t *ot_font = (hb_ot_font_t *) calloc (1, sizeof (hb_ot_font_t));
+
+  if (unlikely (!ot_font))
+    return NULL;
+
+  ot_font->num_glyphs = font->face->get_num_glyphs ();
+
+  {
+    hb_blob_t *hhea_blob = OT::Sanitizer<OT::hhea>::sanitize (font->face->reference_table (HB_OT_TAG_hhea));
+    const OT::hhea *hhea = OT::Sanitizer<OT::hhea>::lock_instance (hhea_blob);
+    ot_font->num_hmetrics = hhea->numberOfHMetrics;
+    hb_blob_destroy (hhea_blob);
+  }
+  ot_font->hmtx_blob = OT::Sanitizer<OT::hmtx>::sanitize (font->face->reference_table (HB_OT_TAG_hmtx));
+  if (unlikely (!ot_font->num_hmetrics ||
+                2 * (ot_font->num_hmetrics + ot_font->num_glyphs) < hb_blob_get_length (ot_font->hmtx_blob)))
+  {
+    hb_blob_destroy (ot_font->hmtx_blob);
+    free (ot_font);
+    return NULL;
+  }
+  ot_font->hmtx = OT::Sanitizer<OT::hmtx>::lock_instance (ot_font->hmtx_blob);
+
+  ot_font->cmap_blob = OT::Sanitizer<OT::cmap>::sanitize (font->face->reference_table (HB_OT_TAG_cmap));
+  const OT::cmap *cmap = OT::Sanitizer<OT::cmap>::lock_instance (ot_font->cmap_blob);
+  const OT::CmapSubtable *subtable = NULL;
+  const OT::CmapSubtable *subtable_uvs = NULL;
+
+  /* 32-bit subtables. */
+  if (!subtable) subtable = cmap->find_subtable (0, 6);
+  if (!subtable) subtable = cmap->find_subtable (0, 4);
+  if (!subtable) subtable = cmap->find_subtable (3, 10);
+  /* 16-bit subtables. */
+  if (!subtable) subtable = cmap->find_subtable (0, 3);
+  if (!subtable) subtable = cmap->find_subtable (3, 1);
+  /* Meh. */
+  if (!subtable) subtable = &OT::Null(OT::CmapSubtable);
+
+  /* UVS subtable. */
+  if (!subtable_uvs) subtable_uvs = cmap->find_subtable (0, 5);
+  /* Meh. */
+  if (!subtable_uvs) subtable_uvs = &OT::Null(OT::CmapSubtable);
+
+  ot_font->cmap = subtable;
+  ot_font->cmap_uvs = subtable_uvs;
+
+  return ot_font;
+}
+
+static void
+_hb_ot_font_destroy (hb_ot_font_t *ot_font)
+{
+  hb_blob_destroy (ot_font->cmap_blob);
+  hb_blob_destroy (ot_font->hmtx_blob);
+
+  free (ot_font);
+}
+
+
+static hb_bool_t
+hb_ot_get_glyph (hb_font_t *font HB_UNUSED,
+                 void *font_data,
+                 hb_codepoint_t unicode,
+                 hb_codepoint_t variation_selector,
+                 hb_codepoint_t *glyph,
+                 void *user_data HB_UNUSED)
+
+{
+  const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
+
+  if (unlikely (variation_selector))
+  {
+    switch (ot_font->cmap_uvs->get_glyph_variant (unicode,
+                                                  variation_selector,
+                                                  glyph))
+    {
+      case OT::GLYPH_VARIANT_NOT_FOUND:         return false;
+      case OT::GLYPH_VARIANT_FOUND:             return true;
+      case OT::GLYPH_VARIANT_USE_DEFAULT:       break;
+    }
+  }
+
+  return ot_font->cmap->get_glyph (unicode, glyph);
+}
+
+static hb_position_t
+hb_ot_get_glyph_h_advance (hb_font_t *font HB_UNUSED,
+                           void *font_data,
+                           hb_codepoint_t glyph,
+                           void *user_data HB_UNUSED)
+{
+  const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
+
+  if (unlikely (glyph >= ot_font->num_glyphs))
+    return 0; /* Maybe better to return notdef's advance instead? */
+
+  if (glyph >= ot_font->num_hmetrics)
+    glyph = ot_font->num_hmetrics - 1;
+
+  return font->em_scale_x (ot_font->hmtx->longHorMetric[glyph].advanceWidth);
+}
+
+static hb_position_t
+hb_ot_get_glyph_v_advance (hb_font_t *font HB_UNUSED,
+                           void *font_data,
+                           hb_codepoint_t glyph,
+                           void *user_data HB_UNUSED)
+{
+  /* TODO */
+  return 0;
+}
+
+static hb_bool_t
+hb_ot_get_glyph_h_origin (hb_font_t *font HB_UNUSED,
+                          void *font_data HB_UNUSED,
+                          hb_codepoint_t glyph HB_UNUSED,
+                          hb_position_t *x HB_UNUSED,
+                          hb_position_t *y HB_UNUSED,
+                          void *user_data HB_UNUSED)
+{
+  /* We always work in the horizontal coordinates. */
+  return true;
+}
+
+static hb_bool_t
+hb_ot_get_glyph_v_origin (hb_font_t *font HB_UNUSED,
+                          void *font_data,
+                          hb_codepoint_t glyph,
+                          hb_position_t *x,
+                          hb_position_t *y,
+                          void *user_data HB_UNUSED)
+{
+  /* TODO */
+  return false;
+}
+
+static hb_position_t
+hb_ot_get_glyph_h_kerning (hb_font_t *font,
+                           void *font_data,
+                           hb_codepoint_t left_glyph,
+                           hb_codepoint_t right_glyph,
+                           void *user_data HB_UNUSED)
+{
+  /* TODO */
+  return 0;
+}
+
+static hb_position_t
+hb_ot_get_glyph_v_kerning (hb_font_t *font HB_UNUSED,
+                           void *font_data HB_UNUSED,
+                           hb_codepoint_t top_glyph HB_UNUSED,
+                           hb_codepoint_t bottom_glyph HB_UNUSED,
+                           void *user_data HB_UNUSED)
+{
+  return 0;
+}
+
+static hb_bool_t
+hb_ot_get_glyph_extents (hb_font_t *font HB_UNUSED,
+                         void *font_data,
+                         hb_codepoint_t glyph,
+                         hb_glyph_extents_t *extents,
+                         void *user_data HB_UNUSED)
+{
+  /* TODO */
+  return false;
+}
+
+static hb_bool_t
+hb_ot_get_glyph_contour_point (hb_font_t *font HB_UNUSED,
+                               void *font_data,
+                               hb_codepoint_t glyph,
+                               unsigned int point_index,
+                               hb_position_t *x,
+                               hb_position_t *y,
+                               void *user_data HB_UNUSED)
+{
+  /* TODO */
+  return false;
+}
+
+static hb_bool_t
+hb_ot_get_glyph_name (hb_font_t *font HB_UNUSED,
+                      void *font_data,
+                      hb_codepoint_t glyph,
+                      char *name, unsigned int size,
+                      void *user_data HB_UNUSED)
+{
+  /* TODO */
+  return false;
+}
+
+static hb_bool_t
+hb_ot_get_glyph_from_name (hb_font_t *font HB_UNUSED,
+                           void *font_data,
+                           const char *name, int len, /* -1 means nul-terminated */
+                           hb_codepoint_t *glyph,
+                           void *user_data HB_UNUSED)
+{
+  /* TODO */
+  return false;
+}
+
+
+static hb_font_funcs_t *
+_hb_ot_get_font_funcs (void)
+{
+  static const hb_font_funcs_t ot_ffuncs = {
+    HB_OBJECT_HEADER_STATIC,
+
+    true, /* immutable */
+
+    {
+#define HB_FONT_FUNC_IMPLEMENT(name) hb_ot_get_##name,
+      HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
+#undef HB_FONT_FUNC_IMPLEMENT
+    }
+  };
+
+  return const_cast<hb_font_funcs_t *> (&ot_ffuncs);
+}
+
+
+void
+hb_ot_font_set_funcs (hb_font_t *font)
+{
+  hb_ot_font_t *ot_font = _hb_ot_font_create (font);
+  if (unlikely (!ot_font))
+    return;
+
+  hb_font_set_funcs (font,
+                     _hb_ot_get_font_funcs (),
+                     ot_font,
+                     (hb_destroy_func_t) _hb_ot_font_destroy);
+}