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-rw-r--r--src/hb-ot-shape.cc596
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diff --git a/src/hb-ot-shape.cc b/src/hb-ot-shape.cc
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+/*
+ * Copyright © 2009,2010 Red Hat, Inc.
+ * Copyright © 2010,2011,2012 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
+ */
+
+#define HB_SHAPER ot
+#define hb_ot_shaper_face_data_t hb_ot_layout_t
+#define hb_ot_shaper_shape_plan_data_t hb_ot_shape_plan_t
+#include "hb-shaper-impl-private.hh"
+
+#include "hb-ot-shape-private.hh"
+#include "hb-ot-shape-complex-private.hh"
+#include "hb-ot-shape-fallback-private.hh"
+#include "hb-ot-shape-normalize-private.hh"
+
+#include "hb-ot-layout-private.hh"
+#include "hb-set-private.hh"
+
+
+static hb_tag_t common_features[] = {
+ HB_TAG('c','c','m','p'),
+ 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 hb_tag_t horizontal_features[] = {
+ HB_TAG('c','a','l','t'),
+ HB_TAG('c','l','i','g'),
+ HB_TAG('c','u','r','s'),
+ HB_TAG('k','e','r','n'),
+ HB_TAG('r','c','l','t'),
+};
+
+/* Note:
+ * Technically speaking, vrt2 and vert are mutually exclusive.
+ * According to the spec, valt and vpal are also mutually exclusive.
+ * But we apply them all for now.
+ */
+static hb_tag_t vertical_features[] = {
+ HB_TAG('v','a','l','t'),
+ HB_TAG('v','e','r','t'),
+ HB_TAG('v','k','r','n'),
+ HB_TAG('v','p','a','l'),
+ HB_TAG('v','r','t','2'),
+};
+
+
+
+static void
+hb_ot_shape_collect_features (hb_ot_shape_planner_t *planner,
+ const hb_segment_properties_t *props,
+ const hb_feature_t *user_features,
+ unsigned int num_user_features)
+{
+ hb_ot_map_builder_t *map = &planner->map;
+
+ switch (props->direction) {
+ case HB_DIRECTION_LTR:
+ map->add_bool_feature (HB_TAG ('l','t','r','a'));
+ map->add_bool_feature (HB_TAG ('l','t','r','m'));
+ break;
+ case HB_DIRECTION_RTL:
+ map->add_bool_feature (HB_TAG ('r','t','l','a'));
+ map->add_bool_feature (HB_TAG ('r','t','l','m'), false);
+ break;
+ case HB_DIRECTION_TTB:
+ case HB_DIRECTION_BTT:
+ case HB_DIRECTION_INVALID:
+ default:
+ break;
+ }
+
+#define ADD_FEATURES(array) \
+ HB_STMT_START { \
+ for (unsigned int i = 0; i < ARRAY_LENGTH (array); i++) \
+ map->add_bool_feature (array[i]); \
+ } HB_STMT_END
+
+ if (planner->shaper->collect_features)
+ planner->shaper->collect_features (planner);
+
+ ADD_FEATURES (common_features);
+
+ if (HB_DIRECTION_IS_HORIZONTAL (props->direction))
+ ADD_FEATURES (horizontal_features);
+ else
+ ADD_FEATURES (vertical_features);
+
+ if (planner->shaper->override_features)
+ planner->shaper->override_features (planner);
+
+#undef ADD_FEATURES
+
+ for (unsigned int i = 0; i < num_user_features; i++) {
+ const hb_feature_t *feature = &user_features[i];
+ map->add_feature (feature->tag, feature->value, (feature->start == 0 && feature->end == (unsigned int) -1));
+ }
+}
+
+
+/*
+ * shaper face data
+ */
+
+hb_ot_shaper_face_data_t *
+_hb_ot_shaper_face_data_create (hb_face_t *face)
+{
+ return _hb_ot_layout_create (face);
+}
+
+void
+_hb_ot_shaper_face_data_destroy (hb_ot_shaper_face_data_t *data)
+{
+ _hb_ot_layout_destroy (data);
+}
+
+
+/*
+ * shaper font data
+ */
+
+struct hb_ot_shaper_font_data_t {};
+
+hb_ot_shaper_font_data_t *
+_hb_ot_shaper_font_data_create (hb_font_t *font)
+{
+ return (hb_ot_shaper_font_data_t *) HB_SHAPER_DATA_SUCCEEDED;
+}
+
+void
+_hb_ot_shaper_font_data_destroy (hb_ot_shaper_font_data_t *data)
+{
+}
+
+
+/*
+ * shaper shape_plan data
+ */
+
+hb_ot_shaper_shape_plan_data_t *
+_hb_ot_shaper_shape_plan_data_create (hb_shape_plan_t *shape_plan,
+ const hb_feature_t *user_features,
+ unsigned int num_user_features)
+{
+ hb_ot_shape_plan_t *plan = (hb_ot_shape_plan_t *) calloc (1, sizeof (hb_ot_shape_plan_t));
+ if (unlikely (!plan))
+ return NULL;
+
+ hb_ot_shape_planner_t planner (shape_plan);
+
+ planner.shaper = hb_ot_shape_complex_categorize (&shape_plan->props);
+
+ hb_ot_shape_collect_features (&planner, &shape_plan->props, user_features, num_user_features);
+
+ planner.compile (*plan);
+
+ if (plan->shaper->data_create) {
+ plan->data = plan->shaper->data_create (plan);
+ if (unlikely (!plan->data))
+ return NULL;
+ }
+
+ return plan;
+}
+
+void
+_hb_ot_shaper_shape_plan_data_destroy (hb_ot_shaper_shape_plan_data_t *plan)
+{
+ if (plan->shaper->data_destroy)
+ plan->shaper->data_destroy (const_cast<void *> (plan->data));
+
+ plan->finish ();
+
+ free (plan);
+}
+
+
+/*
+ * shaper
+ */
+
+struct hb_ot_shape_context_t
+{
+ 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;
+
+ /* Transient stuff */
+ hb_direction_t target_direction;
+};
+
+
+
+/* Main shaper */
+
+
+/* Prepare */
+
+static void
+hb_set_unicode_props (hb_buffer_t *buffer)
+{
+ unsigned int count = buffer->len;
+ for (unsigned int i = 0; i < count; i++)
+ _hb_glyph_info_set_unicode_props (&buffer->info[i], buffer->unicode);
+}
+
+static void
+hb_form_clusters (hb_buffer_t *buffer)
+{
+ unsigned int count = buffer->len;
+ for (unsigned int i = 1; i < count; i++)
+ if (FLAG (_hb_glyph_info_get_general_category (&buffer->info[i])) &
+ (FLAG (HB_UNICODE_GENERAL_CATEGORY_SPACING_MARK) |
+ FLAG (HB_UNICODE_GENERAL_CATEGORY_ENCLOSING_MARK) |
+ FLAG (HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)))
+ buffer->merge_clusters (i - 1, i + 1);
+}
+
+static void
+hb_ensure_native_direction (hb_buffer_t *buffer)
+{
+ hb_direction_t direction = buffer->props.direction;
+
+ /* TODO vertical:
+ * The only BTT vertical script is Ogham, but it's not clear to me whether OpenType
+ * Ogham fonts are supposed to be implemented BTT or not. Need to research that
+ * first. */
+ if ((HB_DIRECTION_IS_HORIZONTAL (direction) && direction != hb_script_get_horizontal_direction (buffer->props.script)) ||
+ (HB_DIRECTION_IS_VERTICAL (direction) && direction != HB_DIRECTION_TTB))
+ {
+ hb_buffer_reverse_clusters (buffer);
+ buffer->props.direction = HB_DIRECTION_REVERSE (buffer->props.direction);
+ }
+}
+
+
+/* Substitute */
+
+static inline void
+hb_ot_mirror_chars (hb_ot_shape_context_t *c)
+{
+ if (HB_DIRECTION_IS_FORWARD (c->target_direction))
+ return;
+
+ hb_unicode_funcs_t *unicode = c->buffer->unicode;
+ 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 = unicode->mirroring (c->buffer->info[i].codepoint);
+ if (likely (codepoint == c->buffer->info[i].codepoint))
+ c->buffer->info[i].mask |= rtlm_mask;
+ else
+ c->buffer->info[i].codepoint = codepoint;
+ }
+}
+
+static inline void
+hb_ot_shape_setup_masks (hb_ot_shape_context_t *c)
+{
+ hb_ot_map_t *map = &c->plan->map;
+
+ hb_mask_t global_mask = map->get_global_mask ();
+ c->buffer->reset_masks (global_mask);
+
+ if (c->plan->shaper->setup_masks)
+ c->plan->shaper->setup_masks (c->plan, c->buffer, c->font);
+
+ 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 = map->get_mask (feature->tag, &shift);
+ c->buffer->set_masks (feature->value << shift, mask, feature->start, feature->end);
+ }
+ }
+}
+
+static inline void
+hb_ot_map_glyphs_fast (hb_buffer_t *buffer)
+{
+ /* Normalization process sets up glyph_index(), we just copy it. */
+ unsigned int count = buffer->len;
+ for (unsigned int i = 0; i < count; i++)
+ buffer->info[i].codepoint = buffer->info[i].glyph_index();
+}
+
+static inline void
+hb_ot_substitute_default (hb_ot_shape_context_t *c)
+{
+ if (c->plan->shaper->preprocess_text)
+ c->plan->shaper->preprocess_text (c->plan, c->buffer, c->font);
+
+ hb_ot_mirror_chars (c);
+
+ HB_BUFFER_ALLOCATE_VAR (c->buffer, glyph_index);
+
+ _hb_ot_shape_normalize (c->font, c->buffer,
+ c->plan->shaper->normalization_preference ?
+ c->plan->shaper->normalization_preference (c->plan) :
+ HB_OT_SHAPE_NORMALIZATION_MODE_DEFAULT);
+
+ hb_ot_shape_setup_masks (c);
+
+ hb_ot_map_glyphs_fast (c->buffer);
+
+ HB_BUFFER_DEALLOCATE_VAR (c->buffer, glyph_index);
+}
+
+static inline void
+hb_synthesize_glyph_classes (hb_ot_shape_context_t *c)
+{
+ unsigned int count = c->buffer->len;
+ for (unsigned int i = 0; i < count; i++)
+ c->buffer->info[i].glyph_props() = _hb_glyph_info_get_general_category (&c->buffer->info[i]) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK ?
+ HB_OT_LAYOUT_GLYPH_CLASS_MARK :
+ HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH;
+}
+
+
+static inline void
+hb_ot_substitute_complex (hb_ot_shape_context_t *c)
+{
+ hb_ot_layout_substitute_start (c->font, c->buffer);
+
+ if (!hb_ot_layout_has_glyph_classes (c->face))
+ hb_synthesize_glyph_classes (c);
+
+ if (hb_ot_layout_has_substitution (c->face))
+ c->plan->substitute (c->font, c->buffer);
+
+ hb_ot_layout_substitute_finish (c->font, c->buffer);
+
+ return;
+}
+
+static inline void
+hb_ot_substitute (hb_ot_shape_context_t *c)
+{
+ hb_ot_substitute_default (c);
+ hb_ot_substitute_complex (c);
+}
+
+/* Position */
+
+static inline void
+hb_ot_position_default (hb_ot_shape_context_t *c)
+{
+ hb_ot_layout_position_start (c->font, c->buffer);
+
+ unsigned int count = c->buffer->len;
+ for (unsigned int i = 0; i < count; i++) {
+ c->font->get_glyph_advance_for_direction (c->buffer->info[i].codepoint,
+ c->buffer->props.direction,
+ &c->buffer->pos[i].x_advance,
+ &c->buffer->pos[i].y_advance);
+ c->font->subtract_glyph_origin_for_direction (c->buffer->info[i].codepoint,
+ c->buffer->props.direction,
+ &c->buffer->pos[i].x_offset,
+ &c->buffer->pos[i].y_offset);
+ }
+}
+
+static inline bool
+hb_ot_position_complex (hb_ot_shape_context_t *c)
+{
+ bool ret = false;
+
+ if (hb_ot_layout_has_positioning (c->face))
+ {
+ /* Change glyph origin to what GPOS expects, apply GPOS, change it back. */
+
+ unsigned int count = c->buffer->len;
+ for (unsigned int i = 0; i < count; i++) {
+ c->font->add_glyph_origin_for_direction (c->buffer->info[i].codepoint,
+ HB_DIRECTION_LTR,
+ &c->buffer->pos[i].x_offset,
+ &c->buffer->pos[i].y_offset);
+ }
+
+ c->plan->position (c->font, c->buffer);
+
+ for (unsigned int i = 0; i < count; i++) {
+ c->font->subtract_glyph_origin_for_direction (c->buffer->info[i].codepoint,
+ HB_DIRECTION_LTR,
+ &c->buffer->pos[i].x_offset,
+ &c->buffer->pos[i].y_offset);
+ }
+
+ ret = true;
+ }
+
+ hb_ot_layout_position_finish (c->font, c->buffer, c->plan->shaper->zero_width_attached_marks);
+
+ return ret;
+}
+
+static inline void
+hb_ot_position_complex_fallback (hb_ot_shape_context_t *c)
+{
+ _hb_ot_shape_fallback_position (c->plan, c->font, c->buffer);
+}
+
+static inline void
+hb_ot_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 x_kern, y_kern, kern1, kern2;
+ c->font->get_glyph_kerning_for_direction (c->buffer->info[i - 1].codepoint, c->buffer->info[i].codepoint,
+ c->buffer->props.direction,
+ &x_kern, &y_kern);
+
+ kern1 = x_kern >> 1;
+ kern2 = x_kern - kern1;
+ c->buffer->pos[i - 1].x_advance += kern1;
+ c->buffer->pos[i].x_advance += kern2;
+ c->buffer->pos[i].x_offset += kern2;
+
+ kern1 = y_kern >> 1;
+ kern2 = y_kern - kern1;
+ c->buffer->pos[i - 1].y_advance += kern1;
+ c->buffer->pos[i].y_advance += kern2;
+ c->buffer->pos[i].y_offset += kern2;
+ }
+}
+
+static inline void
+hb_position_complex_fallback_visual (hb_ot_shape_context_t *c)
+{
+ hb_ot_truetype_kern (c);
+}
+
+static inline void
+hb_ot_position (hb_ot_shape_context_t *c)
+{
+ hb_ot_position_default (c);
+
+ hb_bool_t fallback = !hb_ot_position_complex (c);
+
+ if (fallback)
+ hb_ot_position_complex_fallback (c);
+
+ if (HB_DIRECTION_IS_BACKWARD (c->buffer->props.direction))
+ hb_buffer_reverse (c->buffer);
+
+ if (fallback)
+ hb_position_complex_fallback_visual (c);
+}
+
+
+/* Post-process */
+
+static void
+hb_ot_hide_zerowidth (hb_ot_shape_context_t *c)
+{
+ hb_codepoint_t space;
+ if (!c->font->get_glyph (' ', 0, &space))
+ return; /* No point! */
+
+ unsigned int count = c->buffer->len;
+ for (unsigned int i = 0; i < count; i++)
+ if (unlikely (!is_a_ligature (c->buffer->info[i]) &&
+ _hb_glyph_info_is_zero_width (&c->buffer->info[i]))) {
+ c->buffer->info[i].codepoint = space;
+ c->buffer->pos[i].x_advance = 0;
+ c->buffer->pos[i].y_advance = 0;
+ }
+}
+
+
+/* Pull it all together! */
+
+static void
+hb_ot_shape_internal (hb_ot_shape_context_t *c)
+{
+ c->buffer->deallocate_var_all ();
+
+ /* Save the original direction, we use it later. */
+ c->target_direction = c->buffer->props.direction;
+
+ HB_BUFFER_ALLOCATE_VAR (c->buffer, unicode_props0);
+ HB_BUFFER_ALLOCATE_VAR (c->buffer, unicode_props1);
+
+ c->buffer->clear_output ();
+
+ hb_set_unicode_props (c->buffer);
+ hb_form_clusters (c->buffer);
+
+ hb_ensure_native_direction (c->buffer);
+
+ hb_ot_substitute (c);
+ hb_ot_position (c);
+
+ hb_ot_hide_zerowidth (c);
+
+ HB_BUFFER_DEALLOCATE_VAR (c->buffer, unicode_props1);
+ HB_BUFFER_DEALLOCATE_VAR (c->buffer, unicode_props0);
+
+ c->buffer->props.direction = c->target_direction;
+
+ c->buffer->deallocate_var_all ();
+}
+
+
+hb_bool_t
+_hb_ot_shape (hb_shape_plan_t *shape_plan,
+ hb_font_t *font,
+ hb_buffer_t *buffer,
+ const hb_feature_t *features,
+ unsigned int num_features)
+{
+ hb_ot_shape_context_t c = {HB_SHAPER_DATA_GET (shape_plan), font, font->face, buffer, features, num_features};
+ hb_ot_shape_internal (&c);
+
+ return true;
+}
+
+
+
+static inline void
+hb_ot_map_glyphs_dumb (hb_font_t *font,
+ hb_buffer_t *buffer)
+{
+ unsigned int count = buffer->len;
+ for (unsigned int i = 0; i < count; i++)
+ font->get_glyph (buffer->cur().codepoint, 0, &buffer->cur().codepoint);
+}
+
+void
+hb_ot_shape_glyphs_closure (hb_font_t *font,
+ hb_buffer_t *buffer,
+ const hb_feature_t *features,
+ unsigned int num_features,
+ hb_set_t *glyphs)
+{
+ hb_ot_shape_plan_t plan;
+
+ buffer->guess_properties ();
+
+ /* TODO cache / ensure correct backend, etc. */
+ hb_shape_plan_t *shape_plan = hb_shape_plan_create (font->face, &buffer->props, features, num_features, NULL);
+
+ /* TODO: normalization? have shapers do closure()? */
+ /* TODO: Deal with mirrored chars? */
+ hb_ot_map_glyphs_dumb (font, buffer);
+
+ /* Seed it. It's user's responsibility to have cleard glyphs
+ * if that's what they desire. */
+ unsigned int count = buffer->len;
+ for (unsigned int i = 0; i < count; i++)
+ glyphs->add (buffer->info[i].codepoint);
+
+ /* And find transitive closure. */
+ hb_set_t copy;
+ copy.init ();
+
+ do {
+ copy.set (glyphs);
+ HB_SHAPER_DATA_GET (shape_plan)->substitute_closure (font->face, glyphs);
+ } while (!copy.equal (glyphs));
+
+ hb_shape_plan_destroy (shape_plan);
+}
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