1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/harfbuzz/src/hb-ot-shape-complex-arabic-fallback.hh Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,260 @@
1.4 +/*
1.5 + * Copyright © 2012 Google, Inc.
1.6 + *
1.7 + * This is part of HarfBuzz, a text shaping library.
1.8 + *
1.9 + * Permission is hereby granted, without written agreement and without
1.10 + * license or royalty fees, to use, copy, modify, and distribute this
1.11 + * software and its documentation for any purpose, provided that the
1.12 + * above copyright notice and the following two paragraphs appear in
1.13 + * all copies of this software.
1.14 + *
1.15 + * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
1.16 + * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
1.17 + * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
1.18 + * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
1.19 + * DAMAGE.
1.20 + *
1.21 + * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
1.22 + * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
1.23 + * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
1.24 + * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
1.25 + * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
1.26 + *
1.27 + * Google Author(s): Behdad Esfahbod
1.28 + */
1.29 +
1.30 +#ifndef HB_OT_SHAPE_COMPLEX_ARABIC_FALLBACK_HH
1.31 +#define HB_OT_SHAPE_COMPLEX_ARABIC_FALLBACK_HH
1.32 +
1.33 +#include "hb-private.hh"
1.34 +
1.35 +#include "hb-ot-shape-private.hh"
1.36 +#include "hb-ot-layout-gsub-table.hh"
1.37 +
1.38 +
1.39 +static const hb_tag_t arabic_fallback_features[] =
1.40 +{
1.41 + HB_TAG('i','n','i','t'),
1.42 + HB_TAG('m','e','d','i'),
1.43 + HB_TAG('f','i','n','a'),
1.44 + HB_TAG('i','s','o','l'),
1.45 + HB_TAG('r','l','i','g'),
1.46 +};
1.47 +
1.48 +/* Same order as the fallback feature array */
1.49 +enum {
1.50 + FALLBACK_INIT,
1.51 + FALLBACK_MEDI,
1.52 + FALLBACK_FINA,
1.53 + FALLBACK_ISOL,
1.54 + FALLBACK_RLIG,
1.55 + ARABIC_NUM_FALLBACK_FEATURES
1.56 +};
1.57 +
1.58 +static OT::SubstLookup *
1.59 +arabic_fallback_synthesize_lookup_single (const hb_ot_shape_plan_t *plan HB_UNUSED,
1.60 + hb_font_t *font,
1.61 + unsigned int feature_index)
1.62 +{
1.63 + OT::GlyphID glyphs[SHAPING_TABLE_LAST - SHAPING_TABLE_FIRST + 1];
1.64 + OT::GlyphID substitutes[SHAPING_TABLE_LAST - SHAPING_TABLE_FIRST + 1];
1.65 + unsigned int num_glyphs = 0;
1.66 +
1.67 + /* Populate arrays */
1.68 + for (hb_codepoint_t u = SHAPING_TABLE_FIRST; u < SHAPING_TABLE_LAST + 1; u++)
1.69 + {
1.70 + hb_codepoint_t s = shaping_table[u - SHAPING_TABLE_FIRST][feature_index];
1.71 + hb_codepoint_t u_glyph, s_glyph;
1.72 +
1.73 + if (!s ||
1.74 + !hb_font_get_glyph (font, u, 0, &u_glyph) ||
1.75 + !hb_font_get_glyph (font, s, 0, &s_glyph) ||
1.76 + u_glyph == s_glyph ||
1.77 + u_glyph > 0xFFFF || s_glyph > 0xFFFF)
1.78 + continue;
1.79 +
1.80 + glyphs[num_glyphs].set (u_glyph);
1.81 + substitutes[num_glyphs].set (s_glyph);
1.82 +
1.83 + num_glyphs++;
1.84 + }
1.85 +
1.86 + /* Bubble-sort!
1.87 + * May not be good-enough for presidential candidate interviews, but good-enough for us... */
1.88 + hb_bubble_sort (&glyphs[0], num_glyphs, OT::GlyphID::cmp, &substitutes[0]);
1.89 +
1.90 + OT::Supplier<OT::GlyphID> glyphs_supplier (glyphs, num_glyphs);
1.91 + OT::Supplier<OT::GlyphID> substitutes_supplier (substitutes, num_glyphs);
1.92 +
1.93 + /* Each glyph takes four bytes max, and there's some overhead. */
1.94 + char buf[(SHAPING_TABLE_LAST - SHAPING_TABLE_FIRST + 1) * 4 + 128];
1.95 + OT::hb_serialize_context_t c (buf, sizeof (buf));
1.96 + OT::SubstLookup *lookup = c.start_serialize<OT::SubstLookup> ();
1.97 + bool ret = lookup->serialize_single (&c,
1.98 + OT::LookupFlag::IgnoreMarks,
1.99 + glyphs_supplier,
1.100 + substitutes_supplier,
1.101 + num_glyphs);
1.102 + c.end_serialize ();
1.103 + /* TODO sanitize the results? */
1.104 +
1.105 + return ret ? c.copy<OT::SubstLookup> () : NULL;
1.106 +}
1.107 +
1.108 +static OT::SubstLookup *
1.109 +arabic_fallback_synthesize_lookup_ligature (const hb_ot_shape_plan_t *plan HB_UNUSED,
1.110 + hb_font_t *font)
1.111 +{
1.112 + OT::GlyphID first_glyphs[ARRAY_LENGTH_CONST (ligature_table)];
1.113 + unsigned int first_glyphs_indirection[ARRAY_LENGTH_CONST (ligature_table)];
1.114 + unsigned int ligature_per_first_glyph_count_list[ARRAY_LENGTH_CONST (first_glyphs)];
1.115 + unsigned int num_first_glyphs = 0;
1.116 +
1.117 + /* We know that all our ligatures are 2-component */
1.118 + OT::GlyphID ligature_list[ARRAY_LENGTH_CONST (first_glyphs) * ARRAY_LENGTH_CONST(ligature_table[0].ligatures)];
1.119 + unsigned int component_count_list[ARRAY_LENGTH_CONST (ligature_list)];
1.120 + OT::GlyphID component_list[ARRAY_LENGTH_CONST (ligature_list) * 1/* One extra component per ligature */];
1.121 + unsigned int num_ligatures = 0;
1.122 +
1.123 + /* Populate arrays */
1.124 +
1.125 + /* Sort out the first-glyphs */
1.126 + for (unsigned int first_glyph_idx = 0; first_glyph_idx < ARRAY_LENGTH (first_glyphs); first_glyph_idx++)
1.127 + {
1.128 + hb_codepoint_t first_u = ligature_table[first_glyph_idx].first;
1.129 + hb_codepoint_t first_glyph;
1.130 + if (!hb_font_get_glyph (font, first_u, 0, &first_glyph))
1.131 + continue;
1.132 + first_glyphs[num_first_glyphs].set (first_glyph);
1.133 + ligature_per_first_glyph_count_list[num_first_glyphs] = 0;
1.134 + first_glyphs_indirection[num_first_glyphs] = first_glyph_idx;
1.135 + num_first_glyphs++;
1.136 + }
1.137 + hb_bubble_sort (&first_glyphs[0], num_first_glyphs, OT::GlyphID::cmp, &first_glyphs_indirection[0]);
1.138 +
1.139 + /* Now that the first-glyphs are sorted, walk again, populate ligatures. */
1.140 + for (unsigned int i = 0; i < num_first_glyphs; i++)
1.141 + {
1.142 + unsigned int first_glyph_idx = first_glyphs_indirection[i];
1.143 +
1.144 + for (unsigned int second_glyph_idx = 0; second_glyph_idx < ARRAY_LENGTH (ligature_table[0].ligatures); second_glyph_idx++)
1.145 + {
1.146 + hb_codepoint_t second_u = ligature_table[first_glyph_idx].ligatures[second_glyph_idx].second;
1.147 + hb_codepoint_t ligature_u = ligature_table[first_glyph_idx].ligatures[second_glyph_idx].ligature;
1.148 + hb_codepoint_t second_glyph, ligature_glyph;
1.149 + if (!second_u ||
1.150 + !hb_font_get_glyph (font, second_u, 0, &second_glyph) ||
1.151 + !hb_font_get_glyph (font, ligature_u, 0, &ligature_glyph))
1.152 + continue;
1.153 +
1.154 + ligature_per_first_glyph_count_list[i]++;
1.155 +
1.156 + ligature_list[num_ligatures].set (ligature_glyph);
1.157 + component_count_list[num_ligatures] = 2;
1.158 + component_list[num_ligatures].set (second_glyph);
1.159 + num_ligatures++;
1.160 + }
1.161 + }
1.162 +
1.163 + OT::Supplier<OT::GlyphID> first_glyphs_supplier (first_glyphs, num_first_glyphs);
1.164 + OT::Supplier<unsigned int > ligature_per_first_glyph_count_supplier (ligature_per_first_glyph_count_list, num_first_glyphs);
1.165 + OT::Supplier<OT::GlyphID> ligatures_supplier (ligature_list, num_ligatures);
1.166 + OT::Supplier<unsigned int > component_count_supplier (component_count_list, num_ligatures);
1.167 + OT::Supplier<OT::GlyphID> component_supplier (component_list, num_ligatures);
1.168 +
1.169 + /* 16 bytes per ligature ought to be enough... */
1.170 + char buf[ARRAY_LENGTH_CONST (ligature_list) * 16 + 128];
1.171 + OT::hb_serialize_context_t c (buf, sizeof (buf));
1.172 + OT::SubstLookup *lookup = c.start_serialize<OT::SubstLookup> ();
1.173 + bool ret = lookup->serialize_ligature (&c,
1.174 + OT::LookupFlag::IgnoreMarks,
1.175 + first_glyphs_supplier,
1.176 + ligature_per_first_glyph_count_supplier,
1.177 + num_first_glyphs,
1.178 + ligatures_supplier,
1.179 + component_count_supplier,
1.180 + component_supplier);
1.181 +
1.182 + c.end_serialize ();
1.183 + /* TODO sanitize the results? */
1.184 +
1.185 + return ret ? c.copy<OT::SubstLookup> () : NULL;
1.186 +}
1.187 +
1.188 +static OT::SubstLookup *
1.189 +arabic_fallback_synthesize_lookup (const hb_ot_shape_plan_t *plan,
1.190 + hb_font_t *font,
1.191 + unsigned int feature_index)
1.192 +{
1.193 + if (feature_index < 4)
1.194 + return arabic_fallback_synthesize_lookup_single (plan, font, feature_index);
1.195 + else
1.196 + return arabic_fallback_synthesize_lookup_ligature (plan, font);
1.197 +}
1.198 +
1.199 +struct arabic_fallback_plan_t
1.200 +{
1.201 + ASSERT_POD ();
1.202 +
1.203 + hb_mask_t mask_array[ARABIC_NUM_FALLBACK_FEATURES];
1.204 + OT::SubstLookup *lookup_array[ARABIC_NUM_FALLBACK_FEATURES];
1.205 + hb_ot_layout_lookup_accelerator_t accel_array[ARABIC_NUM_FALLBACK_FEATURES];
1.206 +};
1.207 +
1.208 +static const arabic_fallback_plan_t arabic_fallback_plan_nil = {};
1.209 +
1.210 +static arabic_fallback_plan_t *
1.211 +arabic_fallback_plan_create (const hb_ot_shape_plan_t *plan,
1.212 + hb_font_t *font)
1.213 +{
1.214 + arabic_fallback_plan_t *fallback_plan = (arabic_fallback_plan_t *) calloc (1, sizeof (arabic_fallback_plan_t));
1.215 + if (unlikely (!fallback_plan))
1.216 + return const_cast<arabic_fallback_plan_t *> (&arabic_fallback_plan_nil);
1.217 +
1.218 + for (unsigned int i = 0; i < ARABIC_NUM_FALLBACK_FEATURES; i++)
1.219 + {
1.220 + fallback_plan->mask_array[i] = plan->map.get_1_mask (arabic_fallback_features[i]);
1.221 + if (fallback_plan->mask_array[i]) {
1.222 + fallback_plan->lookup_array[i] = arabic_fallback_synthesize_lookup (plan, font, i);
1.223 + if (fallback_plan->lookup_array[i])
1.224 + fallback_plan->accel_array[i].init (*fallback_plan->lookup_array[i]);
1.225 + }
1.226 + }
1.227 +
1.228 + return fallback_plan;
1.229 +}
1.230 +
1.231 +static void
1.232 +arabic_fallback_plan_destroy (arabic_fallback_plan_t *fallback_plan)
1.233 +{
1.234 + if (!fallback_plan || fallback_plan == &arabic_fallback_plan_nil)
1.235 + return;
1.236 +
1.237 + for (unsigned int i = 0; i < ARABIC_NUM_FALLBACK_FEATURES; i++)
1.238 + if (fallback_plan->lookup_array[i])
1.239 + {
1.240 + fallback_plan->accel_array[i].fini (fallback_plan->lookup_array[i]);
1.241 + free (fallback_plan->lookup_array[i]);
1.242 + }
1.243 +
1.244 + free (fallback_plan);
1.245 +}
1.246 +
1.247 +static void
1.248 +arabic_fallback_plan_shape (arabic_fallback_plan_t *fallback_plan,
1.249 + hb_font_t *font,
1.250 + hb_buffer_t *buffer)
1.251 +{
1.252 + OT::hb_apply_context_t c (0, font, buffer);
1.253 + for (unsigned int i = 0; i < ARABIC_NUM_FALLBACK_FEATURES; i++)
1.254 + if (fallback_plan->lookup_array[i]) {
1.255 + c.set_lookup_mask (fallback_plan->mask_array[i]);
1.256 + hb_ot_layout_substitute_lookup (&c,
1.257 + *fallback_plan->lookup_array[i],
1.258 + fallback_plan->accel_array[i]);
1.259 + }
1.260 +}
1.261 +
1.262 +
1.263 +#endif /* HB_OT_SHAPE_COMPLEX_ARABIC_FALLBACK_HH */
