harfbuzz: check in harfbuzz-ng, add gyp define to use it

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

+/*
+ * Copyright (C) 2009,2010  Red Hat, Inc.
+ * Copyright (C) 2010  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.
+ *
+ * Red Hat Author(s): Behdad Esfahbod
+ * Google Author(s): Behdad Esfahbod
+ */
+
+#include "hb-ot-shape-private.hh"
+#include "hb-ot-shape-complex-private.hh"
+
+HB_BEGIN_DECLS
+
+
+/* XXX vertical */
+hb_tag_t default_features[] = {
+  HB_TAG('c','a','l','t'),
+  HB_TAG('c','c','m','p'),
+  HB_TAG('c','l','i','g'),
+  HB_TAG('c','s','w','h'),
+  HB_TAG('c','u','r','s'),
+  HB_TAG('k','e','r','n'),
+  HB_TAG('l','i','g','a'),
+  HB_TAG('l','o','c','l'),
+  HB_TAG('m','a','r','k'),
+  HB_TAG('m','k','m','k'),
+  HB_TAG('r','l','i','g')
+};
+
+static void
+hb_ot_shape_collect_features (hb_ot_shape_plan_t       *plan,
+                              const hb_segment_properties_t  *props,
+                              const hb_feature_t       *user_features,
+                              unsigned int              num_user_features)
+{
+  switch (props->direction) {
+    case HB_DIRECTION_LTR:
+      plan->map.add_bool_feature (HB_TAG ('l','t','r','a'));
+      plan->map.add_bool_feature (HB_TAG ('l','t','r','m'));
+      break;
+    case HB_DIRECTION_RTL:
+      plan->map.add_bool_feature (HB_TAG ('r','t','l','a'));
+      plan->map.add_bool_feature (HB_TAG ('r','t','l','m'), false);
+      break;
+    case HB_DIRECTION_TTB:
+    case HB_DIRECTION_BTT:
+    default:
+      break;
+  }
+
+  for (unsigned int i = 0; i < ARRAY_LENGTH (default_features); i++)
+    plan->map.add_bool_feature (default_features[i]);
+
+  hb_ot_shape_complex_collect_features (plan, props);
+
+  for (unsigned int i = 0; i < num_user_features; i++) {
+    const hb_feature_t *feature = &user_features[i];
+    plan->map.add_feature (feature->tag, feature->value, (feature->start == 0 && feature->end == (unsigned int) -1));
+  }
+}
+
+
+static void
+hb_ot_shape_setup_masks (hb_ot_shape_context_t *c)
+{
+  hb_mask_t global_mask = c->plan->map.get_global_mask ();
+  c->buffer->reset_masks (global_mask);
+
+  hb_ot_shape_complex_setup_masks (c); /* BUFFER: Clobbers var2 */
+
+  for (unsigned int i = 0; i < c->num_user_features; i++)
+  {
+    const hb_feature_t *feature = &c->user_features[i];
+    if (!(feature->start == 0 && feature->end == (unsigned int)-1)) {
+      unsigned int shift;
+      hb_mask_t mask = c->plan->map.get_mask (feature->tag, &shift);
+      c->buffer->set_masks (feature->value << shift, mask, feature->start, feature->end);
+    }
+  }
+}
+
+
+static void
+hb_ot_substitute_complex (hb_ot_shape_context_t *c)
+{
+  if (!hb_ot_layout_has_substitution (c->face))
+    return;
+
+  c->plan->map.substitute (c->face, c->buffer);
+
+  c->applied_substitute_complex = TRUE;
+  return;
+}
+
+static void
+hb_ot_position_complex (hb_ot_shape_context_t *c)
+{
+
+  if (!hb_ot_layout_has_positioning (c->face))
+    return;
+
+  c->plan->map.position (c->font, c->face, c->buffer);
+
+  hb_ot_layout_position_finish (c->buffer);
+
+  c->applied_position_complex = TRUE;
+  return;
+}
+
+
+/* Main shaper */
+
+/* Prepare */
+
+static inline hb_bool_t
+is_variation_selector (hb_codepoint_t unicode)
+{
+  return unlikely ((unicode >=  0x180B && unicode <=  0x180D) || /* MONGOLIAN FREE VARIATION SELECTOR ONE..THREE */
+                   (unicode >=  0xFE00 && unicode <=  0xFE0F) || /* VARIATION SELECTOR-1..16 */
+                   (unicode >= 0xE0100 && unicode <= 0xE01EF));  /* VARIATION SELECTOR-17..256 */
+}
+
+static void
+hb_set_unicode_props (hb_ot_shape_context_t *c)
+{
+  hb_unicode_get_general_category_func_t get_general_category = c->buffer->unicode->v.get_general_category;
+  hb_unicode_get_combining_class_func_t get_combining_class = c->buffer->unicode->v.get_combining_class;
+  hb_glyph_info_t *info = c->buffer->info;
+
+  unsigned int count = c->buffer->len;
+  for (unsigned int i = 1; i < count; i++) {
+    info[i].general_category() = get_general_category (info[i].codepoint);
+    info[i].combining_class() = get_combining_class (info[i].codepoint);
+  }
+}
+
+static void
+hb_form_clusters (hb_ot_shape_context_t *c)
+{
+  unsigned int count = c->buffer->len;
+  for (unsigned int i = 1; i < count; i++)
+    if (c->buffer->info[i].general_category() == HB_CATEGORY_NON_SPACING_MARK)
+      c->buffer->info[i].cluster = c->buffer->info[i - 1].cluster;
+}
+
+static void
+hb_ensure_native_direction (hb_ot_shape_context_t *c)
+{
+  hb_direction_t direction = c->buffer->props.direction;
+
+  /* TODO vertical */
+  if (HB_DIRECTION_IS_HORIZONTAL (direction) &&
+      direction != _hb_script_get_horizontal_direction (c->buffer->props.script))
+  {
+    hb_buffer_reverse_clusters (c->buffer);
+    c->buffer->props.direction = HB_DIRECTION_REVERSE (c->buffer->props.direction);
+  }
+}
+
+static void
+hb_reset_glyph_infos (hb_ot_shape_context_t *c)
+{
+  unsigned int count = c->buffer->len;
+  for (unsigned int i = 0; i < count; i++)
+    c->buffer->info[i].var1.u32 = c->buffer->info[i].var2.u32 = 0;
+}
+
+
+/* Substitute */
+
+static void
+hb_mirror_chars (hb_ot_shape_context_t *c)
+{
+  hb_unicode_get_mirroring_func_t get_mirroring = c->buffer->unicode->v.get_mirroring;
+
+  if (HB_DIRECTION_IS_FORWARD (c->target_direction))
+    return;
+
+  hb_mask_t rtlm_mask = c->plan->map.get_1_mask (HB_TAG ('r','t','l','m'));
+
+  unsigned int count = c->buffer->len;
+  for (unsigned int i = 0; i < count; i++) {
+    hb_codepoint_t codepoint = get_mirroring (c->buffer->info[i].codepoint);
+    if (likely (codepoint == c->buffer->info[i].codepoint))
+      c->buffer->info[i].mask |= rtlm_mask; /* XXX this should be moved to before setting user-feature masks */
+    else
+      c->buffer->info[i].codepoint = codepoint;
+  }
+}
+
+static void
+hb_map_glyphs (hb_font_t    *font,
+               hb_face_t    *face,
+               hb_buffer_t  *buffer)
+{
+  if (unlikely (!buffer->len))
+    return;
+
+  buffer->clear_output ();
+  unsigned int count = buffer->len - 1;
+  for (buffer->i = 0; buffer->i < count;) {
+    if (unlikely (is_variation_selector (buffer->info[buffer->i + 1].codepoint))) {
+      buffer->replace_glyph (hb_font_get_glyph (font, face, buffer->info[buffer->i].codepoint, buffer->info[buffer->i + 1].codepoint));
+      buffer->i++;
+    } else {
+      buffer->replace_glyph (hb_font_get_glyph (font, face, buffer->info[buffer->i].codepoint, 0));
+    }
+  }
+  if (likely (buffer->i < buffer->len))
+    buffer->replace_glyph (hb_font_get_glyph (font, face, buffer->info[buffer->i].codepoint, 0));
+  buffer->swap ();
+}
+
+static void
+hb_substitute_default (hb_ot_shape_context_t *c)
+{
+  hb_map_glyphs (c->font, c->face, c->buffer);
+}
+
+static void
+hb_substitute_complex_fallback (hb_ot_shape_context_t *c HB_UNUSED)
+{
+  /* TODO Arabic */
+}
+
+
+/* Position */
+
+static void
+hb_position_default (hb_ot_shape_context_t *c)
+{
+  hb_buffer_clear_positions (c->buffer);
+
+  unsigned int count = c->buffer->len;
+  for (unsigned int i = 0; i < count; i++) {
+    hb_font_get_glyph_advance (c->font, c->face, c->buffer->info[i].codepoint,
+                               &c->buffer->pos[i].x_advance,
+                               &c->buffer->pos[i].y_advance);
+  }
+}
+
+static void
+hb_position_complex_fallback (hb_ot_shape_context_t *c HB_UNUSED)
+{
+  /* TODO Mark pos */
+}
+
+static void
+hb_truetype_kern (hb_ot_shape_context_t *c)
+{
+  /* TODO Check for kern=0 */
+  unsigned int count = c->buffer->len;
+  for (unsigned int i = 1; i < count; i++) {
+    hb_position_t kern, kern1, kern2;
+    kern = hb_font_get_kerning (c->font, c->face, c->buffer->info[i - 1].codepoint, c->buffer->info[i].codepoint);
+    kern1 = kern >> 1;
+    kern2 = kern - kern1;
+    c->buffer->pos[i - 1].x_advance += kern1;
+    c->buffer->pos[i].x_advance += kern2;
+    c->buffer->pos[i].x_offset += kern2;
+  }
+}
+
+static void
+hb_position_complex_fallback_visual (hb_ot_shape_context_t *c)
+{
+  hb_truetype_kern (c);
+}
+
+
+/* Do it! */
+
+static void
+hb_ot_shape_execute_internal (hb_ot_shape_context_t *c)
+{
+  /* Save the original direction, we use it later. */
+  c->target_direction = c->buffer->props.direction;
+
+  hb_reset_glyph_infos (c); /* BUFFER: Clear buffer var1 and var2 */
+
+  hb_set_unicode_props (c); /* BUFFER: Set general_category and combining_class in var1 */
+
+  hb_ensure_native_direction (c);
+
+  hb_form_clusters (c);
+
+  hb_ot_shape_setup_masks (c); /* BUFFER: Clobbers var2 */
+
+  /* SUBSTITUTE */
+  {
+    /* Mirroring needs to see the original direction */
+    hb_mirror_chars (c);
+
+    hb_substitute_default (c);
+
+    hb_ot_substitute_complex (c);
+
+    if (!c->applied_substitute_complex)
+      hb_substitute_complex_fallback (c);
+  }
+
+  /* POSITION */
+  {
+    hb_position_default (c);
+
+    hb_ot_position_complex (c);
+
+    hb_bool_t position_fallback = !c->applied_position_complex;
+    if (position_fallback)
+      hb_position_complex_fallback (c);
+
+    if (HB_DIRECTION_IS_BACKWARD (c->buffer->props.direction))
+      hb_buffer_reverse (c->buffer);
+
+    if (position_fallback)
+      hb_position_complex_fallback_visual (c);
+  }
+
+  c->buffer->props.direction = c->target_direction;
+}
+
+void
+hb_ot_shape_plan_internal (hb_ot_shape_plan_t       *plan,
+                           hb_face_t                *face,
+                           const hb_segment_properties_t  *props,
+                           const hb_feature_t       *user_features,
+                           unsigned int              num_user_features)
+{
+  plan->shaper = hb_ot_shape_complex_categorize (props);
+
+  hb_ot_shape_collect_features (plan, props, user_features, num_user_features);
+
+  plan->map.compile (face, props);
+}
+
+void
+hb_ot_shape_execute (hb_ot_shape_plan_t *plan,
+                     hb_font_t          *font,
+                     hb_face_t          *face,
+                     hb_buffer_t        *buffer,
+                     const hb_feature_t *user_features,
+                     unsigned int        num_user_features)
+{
+  hb_ot_shape_context_t c = {plan, font, face, buffer, user_features, num_user_features};
+  hb_ot_shape_execute_internal (&c);
+}
+
+void
+hb_ot_shape (hb_font_t    *font,
+             hb_face_t    *face,
+             hb_buffer_t  *buffer,
+             const hb_feature_t *user_features,
+             unsigned int        num_user_features)
+{
+  hb_ot_shape_plan_t plan;
+
+  hb_ot_shape_plan_internal (&plan, face, &buffer->props, user_features, num_user_features);
+  hb_ot_shape_execute (&plan, font, face, buffer, user_features, num_user_features);
+}
+
+
+HB_END_DECLS