/* * Copyright © 2009,2010 Red Hat, Inc. * Copyright © 2010,2011 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-normalize-private.hh" #include "hb-ot-layout-private.hh" #include "hb-set-private.hh" 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'), }; 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'), }; /* 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. */ 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'), }; struct hb_ot_shape_planner_t { hb_ot_map_builder_t map; const hb_ot_complex_shaper_t *shaper; hb_ot_shape_planner_t (void) : map () {} ~hb_ot_shape_planner_t (void) { map.finish (); } inline void compile (hb_face_t *face, const hb_segment_properties_t *props, hb_ot_shape_plan_t &plan) { plan.shaper = shaper; map.compile (face, props, plan.map); } private: NO_COPY (hb_ot_shape_planner_t); }; 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) { switch (props->direction) { case HB_DIRECTION_LTR: planner->map.add_bool_feature (HB_TAG ('l','t','r','a')); planner->map.add_bool_feature (HB_TAG ('l','t','r','m')); break; case HB_DIRECTION_RTL: planner->map.add_bool_feature (HB_TAG ('r','t','l','a')); planner->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++) \ planner->map.add_bool_feature (array[i]); \ } HB_STMT_END if (planner->shaper->collect_features) planner->shaper->collect_features (planner->shaper, &planner->map, props); 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->shaper, &planner->map, props); #undef ADD_FEATURES for (unsigned int i = 0; i < num_user_features; i++) { const hb_feature_t *feature = &user_features[i]; planner->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 *data = (hb_ot_shape_plan_t *) calloc (1, sizeof (hb_ot_shape_plan_t)); if (unlikely (!data)) return NULL; hb_ot_shape_planner_t planner; assert (HB_DIRECTION_IS_VALID (shape_plan->props.direction)); 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 (shape_plan->face, &shape_plan->props, *data); return data; } void _hb_ot_shaper_shape_plan_data_destroy (hb_ot_shaper_shape_plan_data_t *data) { data->map.finish (); free (data); } /* * shaper */ struct hb_ot_shape_context_t { /* Input to hb_ot_shape_internal() */ 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; hb_bool_t applied_position_complex; }; 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); if (c->plan->shaper->setup_masks) c->plan->shaper->setup_masks (c->plan->shaper, &c->plan->map, 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 = c->plan->map.get_mask (feature->tag, &shift); c->buffer->set_masks (feature->value << shift, mask, feature->start, feature->end); } } } /* 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 void hb_mirror_chars (hb_ot_shape_context_t *c) { hb_unicode_funcs_t *unicode = c->buffer->unicode; 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 = unicode->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_buffer_t *buffer) { hb_codepoint_t glyph; if (unlikely (!buffer->len)) return; buffer->clear_output (); unsigned int count = buffer->len - 1; for (buffer->idx = 0; buffer->idx < count;) { if (unlikely (buffer->unicode->is_variation_selector (buffer->cur(+1).codepoint))) { hb_font_get_glyph (font, buffer->cur().codepoint, buffer->cur(+1).codepoint, &glyph); buffer->replace_glyphs (2, 1, &glyph); } else { hb_font_get_glyph (font, buffer->cur().codepoint, 0, &glyph); buffer->replace_glyph (glyph); } } if (likely (buffer->idx < buffer->len)) { hb_font_get_glyph (font, buffer->cur().codepoint, 0, &glyph); buffer->replace_glyph (glyph); } buffer->swap_buffers (); } static void hb_substitute_default (hb_ot_shape_context_t *c) { hb_mirror_chars (c); hb_map_glyphs (c->font, c->buffer); } static 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() = FLAG (_hb_glyph_info_get_general_category (&c->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)) ? HB_OT_LAYOUT_GLYPH_CLASS_MARK : HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH; } static void hb_ot_substitute_complex (hb_ot_shape_context_t *c) { hb_ot_layout_substitute_start (c->face, 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->map.substitute (c->face, c->buffer); hb_ot_layout_substitute_finish (c->face, c->buffer); return; } /* Position */ static void hb_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++) { hb_font_get_glyph_advance_for_direction (c->font, c->buffer->info[i].codepoint, c->buffer->props.direction, &c->buffer->pos[i].x_advance, &c->buffer->pos[i].y_advance); hb_font_subtract_glyph_origin_for_direction (c->font, c->buffer->info[i].codepoint, c->buffer->props.direction, &c->buffer->pos[i].x_offset, &c->buffer->pos[i].y_offset); } } static void hb_zero_mark_advances (hb_ot_shape_context_t *c) { unsigned int count = c->buffer->len; for (unsigned int i = 0; i < count; i++) if (c->buffer->info[i].glyph_props() & HB_OT_LAYOUT_GLYPH_CLASS_MARK) { c->buffer->pos[i].x_advance = 0; c->buffer->pos[i].y_advance = 0; } } static void hb_ot_position_complex (hb_ot_shape_context_t *c) { 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++) { hb_font_add_glyph_origin_for_direction (c->font, c->buffer->info[i].codepoint, HB_DIRECTION_LTR, &c->buffer->pos[i].x_offset, &c->buffer->pos[i].y_offset); } c->plan->map.position (c->font, c->buffer); for (unsigned int i = 0; i < count; i++) { hb_font_subtract_glyph_origin_for_direction (c->font, c->buffer->info[i].codepoint, HB_DIRECTION_LTR, &c->buffer->pos[i].x_offset, &c->buffer->pos[i].y_offset); } c->applied_position_complex = true; } else hb_zero_mark_advances (c); hb_ot_layout_position_finish (c->font, c->buffer, c->plan->shaper->zero_width_attached_marks); return; } 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 x_kern, y_kern, kern1, kern2; hb_font_get_glyph_kerning_for_direction (c->font, 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 void hb_position_complex_fallback_visual (hb_ot_shape_context_t *c) { hb_truetype_kern (c); } static void hb_hide_zerowidth (hb_ot_shape_context_t *c) { hb_codepoint_t space; if (!hb_font_get_glyph (c->font, ' ', 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; } } /* Do it! */ 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_shape_normalize (c->font, c->buffer, c->plan->shaper->normalization_preference ? c->plan->shaper->normalization_preference (c->plan->shaper, &c->buffer->props) : HB_OT_SHAPE_NORMALIZATION_MODE_DEFAULT); hb_ot_shape_setup_masks (c); /* SUBSTITUTE */ { hb_substitute_default (c); hb_ot_substitute_complex (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); } hb_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; } 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_map_glyphs (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++) hb_set_add (glyphs, buffer->info[i].codepoint); /* And find transitive closure. */ hb_set_t copy; copy.init (); do { copy.set (glyphs); HB_SHAPER_DATA_GET (shape_plan)->map.substitute_closure (font->face, glyphs); } while (!copy.equal (glyphs)); hb_shape_plan_destroy (shape_plan); }