| /* |
| * Copyright © 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. |
| * |
| * Google Author(s): Behdad Esfahbod |
| */ |
| |
| #ifndef HB_OT_SHAPER_ARABIC_FALLBACK_HH |
| #define HB_OT_SHAPER_ARABIC_FALLBACK_HH |
| |
| #include "hb.hh" |
| |
| #include "hb-ot-shape.hh" |
| #include "hb-ot-layout-gsub-table.hh" |
| |
| |
| /* Features ordered the same as the entries in shaping_table rows, |
| * followed by rlig. Don't change. |
| * |
| * We currently support one subtable per lookup, and one lookup |
| * per feature. But we allow duplicate features, so we use that! |
| */ |
| static const hb_tag_t arabic_fallback_features[] = |
| { |
| HB_TAG('i','n','i','t'), |
| HB_TAG('m','e','d','i'), |
| HB_TAG('f','i','n','a'), |
| HB_TAG('i','s','o','l'), |
| HB_TAG('r','l','i','g'), |
| HB_TAG('r','l','i','g'), |
| HB_TAG('r','l','i','g'), |
| }; |
| |
| static OT::SubstLookup * |
| arabic_fallback_synthesize_lookup_single (const hb_ot_shape_plan_t *plan HB_UNUSED, |
| hb_font_t *font, |
| unsigned int feature_index) |
| { |
| OT::HBGlyphID16 glyphs[SHAPING_TABLE_LAST - SHAPING_TABLE_FIRST + 1]; |
| OT::HBGlyphID16 substitutes[SHAPING_TABLE_LAST - SHAPING_TABLE_FIRST + 1]; |
| unsigned int num_glyphs = 0; |
| |
| /* Populate arrays */ |
| for (hb_codepoint_t u = SHAPING_TABLE_FIRST; u < SHAPING_TABLE_LAST + 1; u++) |
| { |
| hb_codepoint_t s = shaping_table[u - SHAPING_TABLE_FIRST][feature_index]; |
| hb_codepoint_t u_glyph, s_glyph; |
| |
| if (!s || |
| !hb_font_get_glyph (font, u, 0, &u_glyph) || |
| !hb_font_get_glyph (font, s, 0, &s_glyph) || |
| u_glyph == s_glyph || |
| u_glyph > 0xFFFFu || s_glyph > 0xFFFFu) |
| continue; |
| |
| glyphs[num_glyphs] = u_glyph; |
| substitutes[num_glyphs] = s_glyph; |
| |
| num_glyphs++; |
| } |
| |
| if (!num_glyphs) |
| return nullptr; |
| |
| /* Bubble-sort or something equally good! |
| * May not be good-enough for presidential candidate interviews, but good-enough for us... */ |
| hb_stable_sort (&glyphs[0], num_glyphs, |
| (int(*)(const OT::HBUINT16*, const OT::HBUINT16 *)) OT::HBGlyphID16::cmp, |
| &substitutes[0]); |
| |
| |
| /* Each glyph takes four bytes max, and there's some overhead. */ |
| char buf[(SHAPING_TABLE_LAST - SHAPING_TABLE_FIRST + 1) * 4 + 128]; |
| hb_serialize_context_t c (buf, sizeof (buf)); |
| OT::SubstLookup *lookup = c.start_serialize<OT::SubstLookup> (); |
| bool ret = lookup->serialize_single (&c, |
| OT::LookupFlag::IgnoreMarks, |
| hb_sorted_array (glyphs, num_glyphs), |
| hb_array (substitutes, num_glyphs)); |
| c.end_serialize (); |
| |
| return ret && !c.in_error () ? c.copy<OT::SubstLookup> () : nullptr; |
| } |
| |
| template <typename T> |
| static OT::SubstLookup * |
| arabic_fallback_synthesize_lookup_ligature (const hb_ot_shape_plan_t *plan HB_UNUSED, |
| hb_font_t *font, |
| const T &ligature_table, |
| unsigned lookup_flags) |
| { |
| OT::HBGlyphID16 first_glyphs[ARRAY_LENGTH_CONST (ligature_table)]; |
| unsigned int first_glyphs_indirection[ARRAY_LENGTH_CONST (ligature_table)]; |
| unsigned int ligature_per_first_glyph_count_list[ARRAY_LENGTH_CONST (first_glyphs)]; |
| unsigned int num_first_glyphs = 0; |
| |
| /* We know that all our ligatures have the same number of components. */ |
| OT::HBGlyphID16 ligature_list[ARRAY_LENGTH_CONST (first_glyphs) * ARRAY_LENGTH_CONST(ligature_table[0].ligatures)]; |
| unsigned int component_count_list[ARRAY_LENGTH_CONST (ligature_list)]; |
| OT::HBGlyphID16 component_list[ARRAY_LENGTH_CONST (ligature_list) * |
| ARRAY_LENGTH_CONST (ligature_table[0].ligatures[0].components)]; |
| unsigned int num_ligatures = 0; |
| unsigned int num_components = 0; |
| |
| /* Populate arrays */ |
| |
| /* Sort out the first-glyphs */ |
| for (unsigned int first_glyph_idx = 0; first_glyph_idx < ARRAY_LENGTH (first_glyphs); first_glyph_idx++) |
| { |
| hb_codepoint_t first_u = ligature_table[first_glyph_idx].first; |
| hb_codepoint_t first_glyph; |
| if (!hb_font_get_glyph (font, first_u, 0, &first_glyph)) |
| continue; |
| first_glyphs[num_first_glyphs] = first_glyph; |
| ligature_per_first_glyph_count_list[num_first_glyphs] = 0; |
| first_glyphs_indirection[num_first_glyphs] = first_glyph_idx; |
| num_first_glyphs++; |
| } |
| hb_stable_sort (&first_glyphs[0], num_first_glyphs, |
| (int(*)(const OT::HBUINT16*, const OT::HBUINT16 *)) OT::HBGlyphID16::cmp, |
| &first_glyphs_indirection[0]); |
| |
| /* Now that the first-glyphs are sorted, walk again, populate ligatures. */ |
| for (unsigned int i = 0; i < num_first_glyphs; i++) |
| { |
| unsigned int first_glyph_idx = first_glyphs_indirection[i]; |
| |
| for (unsigned int ligature_idx = 0; ligature_idx < ARRAY_LENGTH (ligature_table[0].ligatures); ligature_idx++) |
| { |
| hb_codepoint_t ligature_u = ligature_table[first_glyph_idx].ligatures[ligature_idx].ligature; |
| hb_codepoint_t ligature_glyph; |
| if (!hb_font_get_glyph (font, ligature_u, 0, &ligature_glyph)) |
| continue; |
| |
| const auto &components = ligature_table[first_glyph_idx].ligatures[ligature_idx].components; |
| unsigned component_count = ARRAY_LENGTH_CONST (components); |
| |
| bool matched = true; |
| for (unsigned j = 0; j < component_count; j++) |
| { |
| hb_codepoint_t component_u = ligature_table[first_glyph_idx].ligatures[ligature_idx].components[j]; |
| hb_codepoint_t component_glyph; |
| if (!component_u || |
| !hb_font_get_nominal_glyph (font, component_u, &component_glyph)) |
| { |
| matched = false; |
| break; |
| } |
| |
| component_list[num_components++] = component_glyph; |
| } |
| if (!matched) |
| continue; |
| |
| component_count_list[num_ligatures] = 1 + component_count; |
| ligature_list[num_ligatures] = ligature_glyph; |
| |
| ligature_per_first_glyph_count_list[i]++; |
| |
| num_ligatures++; |
| } |
| } |
| |
| if (!num_ligatures) |
| return nullptr; |
| |
| |
| /* 16 bytes per ligature ought to be enough... */ |
| char buf[ARRAY_LENGTH_CONST (ligature_list) * 16 + 128]; |
| hb_serialize_context_t c (buf, sizeof (buf)); |
| OT::SubstLookup *lookup = c.start_serialize<OT::SubstLookup> (); |
| bool ret = lookup->serialize_ligature (&c, |
| lookup_flags, |
| hb_sorted_array (first_glyphs, num_first_glyphs), |
| hb_array (ligature_per_first_glyph_count_list, num_first_glyphs), |
| hb_array (ligature_list, num_ligatures), |
| hb_array (component_count_list, num_ligatures), |
| hb_array (component_list, num_components)); |
| c.end_serialize (); |
| |
| return ret && !c.in_error () ? c.copy<OT::SubstLookup> () : nullptr; |
| } |
| |
| static OT::SubstLookup * |
| arabic_fallback_synthesize_lookup (const hb_ot_shape_plan_t *plan, |
| hb_font_t *font, |
| unsigned int feature_index) |
| { |
| if (feature_index < 4) |
| return arabic_fallback_synthesize_lookup_single (plan, font, feature_index); |
| else |
| { |
| switch (feature_index) { |
| case 4: return arabic_fallback_synthesize_lookup_ligature (plan, font, ligature_3_table, OT::LookupFlag::IgnoreMarks); |
| case 5: return arabic_fallback_synthesize_lookup_ligature (plan, font, ligature_table, OT::LookupFlag::IgnoreMarks); |
| case 6: return arabic_fallback_synthesize_lookup_ligature (plan, font, ligature_mark_table, 0); |
| } |
| } |
| assert (false); |
| return nullptr; |
| } |
| |
| #define ARABIC_FALLBACK_MAX_LOOKUPS ARRAY_LENGTH_CONST (arabic_fallback_features) |
| |
| struct arabic_fallback_plan_t |
| { |
| unsigned int num_lookups; |
| bool free_lookups; |
| |
| hb_mask_t mask_array[ARABIC_FALLBACK_MAX_LOOKUPS]; |
| OT::SubstLookup *lookup_array[ARABIC_FALLBACK_MAX_LOOKUPS]; |
| OT::hb_ot_layout_lookup_accelerator_t *accel_array[ARABIC_FALLBACK_MAX_LOOKUPS]; |
| }; |
| |
| #if defined(_WIN32) && !defined(HB_NO_WIN1256) |
| #define HB_WITH_WIN1256 |
| #endif |
| |
| #ifdef HB_WITH_WIN1256 |
| #include "hb-ot-shaper-arabic-win1256.hh" |
| #endif |
| |
| struct ManifestLookup |
| { |
| public: |
| OT::Tag tag; |
| OT::Offset16To<OT::SubstLookup> lookupOffset; |
| public: |
| DEFINE_SIZE_STATIC (6); |
| }; |
| typedef OT::Array16Of<ManifestLookup> Manifest; |
| |
| static bool |
| arabic_fallback_plan_init_win1256 (arabic_fallback_plan_t *fallback_plan HB_UNUSED, |
| const hb_ot_shape_plan_t *plan HB_UNUSED, |
| hb_font_t *font HB_UNUSED) |
| { |
| #ifdef HB_WITH_WIN1256 |
| /* Does this font look like it's Windows-1256-encoded? */ |
| hb_codepoint_t g; |
| if (!(hb_font_get_glyph (font, 0x0627u, 0, &g) && g == 199 /* ALEF */ && |
| hb_font_get_glyph (font, 0x0644u, 0, &g) && g == 225 /* LAM */ && |
| hb_font_get_glyph (font, 0x0649u, 0, &g) && g == 236 /* ALEF MAKSURA */ && |
| hb_font_get_glyph (font, 0x064Au, 0, &g) && g == 237 /* YEH */ && |
| hb_font_get_glyph (font, 0x0652u, 0, &g) && g == 250 /* SUKUN */)) |
| return false; |
| |
| const Manifest &manifest = reinterpret_cast<const Manifest&> (arabic_win1256_gsub_lookups.manifest); |
| static_assert (sizeof (arabic_win1256_gsub_lookups.manifestData) <= |
| ARABIC_FALLBACK_MAX_LOOKUPS * sizeof (ManifestLookup), ""); |
| |
| unsigned j = 0; |
| unsigned int count = manifest.len; |
| for (unsigned int i = 0; i < count; i++) |
| { |
| fallback_plan->mask_array[j] = plan->map.get_1_mask (manifest[i].tag); |
| if (fallback_plan->mask_array[j]) |
| { |
| fallback_plan->lookup_array[j] = const_cast<OT::SubstLookup*> (&(&manifest+manifest[i].lookupOffset)); |
| if (fallback_plan->lookup_array[j]) |
| { |
| fallback_plan->accel_array[j] = OT::hb_ot_layout_lookup_accelerator_t::create (*fallback_plan->lookup_array[j]); |
| j++; |
| } |
| } |
| } |
| |
| fallback_plan->num_lookups = j; |
| fallback_plan->free_lookups = false; |
| |
| return j > 0; |
| #else |
| return false; |
| #endif |
| } |
| |
| static bool |
| arabic_fallback_plan_init_unicode (arabic_fallback_plan_t *fallback_plan, |
| const hb_ot_shape_plan_t *plan, |
| hb_font_t *font) |
| { |
| static_assert ((ARRAY_LENGTH_CONST (arabic_fallback_features) <= ARABIC_FALLBACK_MAX_LOOKUPS), ""); |
| unsigned int j = 0; |
| for (unsigned int i = 0; i < ARRAY_LENGTH(arabic_fallback_features) ; i++) |
| { |
| fallback_plan->mask_array[j] = plan->map.get_1_mask (arabic_fallback_features[i]); |
| if (fallback_plan->mask_array[j]) |
| { |
| fallback_plan->lookup_array[j] = arabic_fallback_synthesize_lookup (plan, font, i); |
| if (fallback_plan->lookup_array[j]) |
| { |
| fallback_plan->accel_array[j] = OT::hb_ot_layout_lookup_accelerator_t::create (*fallback_plan->lookup_array[j]); |
| j++; |
| } |
| } |
| } |
| |
| fallback_plan->num_lookups = j; |
| fallback_plan->free_lookups = true; |
| |
| return j > 0; |
| } |
| |
| static arabic_fallback_plan_t * |
| arabic_fallback_plan_create (const hb_ot_shape_plan_t *plan, |
| hb_font_t *font) |
| { |
| arabic_fallback_plan_t *fallback_plan = (arabic_fallback_plan_t *) hb_calloc (1, sizeof (arabic_fallback_plan_t)); |
| if (unlikely (!fallback_plan)) |
| return const_cast<arabic_fallback_plan_t *> (&Null (arabic_fallback_plan_t)); |
| |
| fallback_plan->num_lookups = 0; |
| fallback_plan->free_lookups = false; |
| |
| /* Try synthesizing GSUB table using Unicode Arabic Presentation Forms, |
| * in case the font has cmap entries for the presentation-forms characters. */ |
| if (arabic_fallback_plan_init_unicode (fallback_plan, plan, font)) |
| return fallback_plan; |
| |
| /* See if this looks like a Windows-1256-encoded font. If it does, use a |
| * hand-coded GSUB table. */ |
| if (arabic_fallback_plan_init_win1256 (fallback_plan, plan, font)) |
| return fallback_plan; |
| |
| assert (fallback_plan->num_lookups == 0); |
| hb_free (fallback_plan); |
| return const_cast<arabic_fallback_plan_t *> (&Null (arabic_fallback_plan_t)); |
| } |
| |
| static void |
| arabic_fallback_plan_destroy (arabic_fallback_plan_t *fallback_plan) |
| { |
| if (!fallback_plan || fallback_plan->num_lookups == 0) |
| return; |
| |
| for (unsigned int i = 0; i < fallback_plan->num_lookups; i++) |
| if (fallback_plan->lookup_array[i]) |
| { |
| hb_free (fallback_plan->accel_array[i]); |
| if (fallback_plan->free_lookups) |
| hb_free (fallback_plan->lookup_array[i]); |
| } |
| |
| hb_free (fallback_plan); |
| } |
| |
| static void |
| arabic_fallback_plan_shape (arabic_fallback_plan_t *fallback_plan, |
| hb_font_t *font, |
| hb_buffer_t *buffer) |
| { |
| OT::hb_ot_apply_context_t c (0, font, buffer, hb_blob_get_empty ()); |
| for (unsigned int i = 0; i < fallback_plan->num_lookups; i++) |
| if (fallback_plan->lookup_array[i]) { |
| c.set_lookup_mask (fallback_plan->mask_array[i]); |
| if (fallback_plan->accel_array[i]) |
| hb_ot_layout_substitute_lookup (&c, |
| *fallback_plan->lookup_array[i], |
| *fallback_plan->accel_array[i]); |
| } |
| } |
| |
| |
| #endif /* HB_OT_SHAPER_ARABIC_FALLBACK_HH */ |