HarfBuzz text shaping engine
http://harfbuzz.github.io/
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
354 lines
12 KiB
354 lines
12 KiB
/* |
|
* 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_SHAPE_COMPLEX_ARABIC_FALLBACK_HH |
|
#define HB_OT_SHAPE_COMPLEX_ARABIC_FALLBACK_HH |
|
|
|
#include "hb-private.hh" |
|
|
|
#include "hb-ot-shape-private.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. */ |
|
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'), |
|
}; |
|
|
|
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::GlyphID glyphs[SHAPING_TABLE_LAST - SHAPING_TABLE_FIRST + 1]; |
|
OT::GlyphID 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].set (u_glyph); |
|
substitutes[num_glyphs].set (s_glyph); |
|
|
|
num_glyphs++; |
|
} |
|
|
|
if (!num_glyphs) |
|
return NULL; |
|
|
|
/* 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, OT::GlyphID::cmp, &substitutes[0]); |
|
|
|
OT::Supplier<OT::GlyphID> glyphs_supplier (glyphs, num_glyphs); |
|
OT::Supplier<OT::GlyphID> substitutes_supplier (substitutes, num_glyphs); |
|
|
|
/* Each glyph takes four bytes max, and there's some overhead. */ |
|
char buf[(SHAPING_TABLE_LAST - SHAPING_TABLE_FIRST + 1) * 4 + 128]; |
|
OT::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, |
|
glyphs_supplier, |
|
substitutes_supplier, |
|
num_glyphs); |
|
c.end_serialize (); |
|
/* TODO sanitize the results? */ |
|
|
|
return ret ? c.copy<OT::SubstLookup> () : NULL; |
|
} |
|
|
|
static OT::SubstLookup * |
|
arabic_fallback_synthesize_lookup_ligature (const hb_ot_shape_plan_t *plan HB_UNUSED, |
|
hb_font_t *font) |
|
{ |
|
OT::GlyphID 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 are 2-component */ |
|
OT::GlyphID 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::GlyphID component_list[ARRAY_LENGTH_CONST (ligature_list) * 1/* One extra component per ligature */]; |
|
unsigned int num_ligatures = 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].set (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, OT::GlyphID::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 second_glyph_idx = 0; second_glyph_idx < ARRAY_LENGTH (ligature_table[0].ligatures); second_glyph_idx++) |
|
{ |
|
hb_codepoint_t second_u = ligature_table[first_glyph_idx].ligatures[second_glyph_idx].second; |
|
hb_codepoint_t ligature_u = ligature_table[first_glyph_idx].ligatures[second_glyph_idx].ligature; |
|
hb_codepoint_t second_glyph, ligature_glyph; |
|
if (!second_u || |
|
!hb_font_get_glyph (font, second_u, 0, &second_glyph) || |
|
!hb_font_get_glyph (font, ligature_u, 0, &ligature_glyph)) |
|
continue; |
|
|
|
ligature_per_first_glyph_count_list[i]++; |
|
|
|
ligature_list[num_ligatures].set (ligature_glyph); |
|
component_count_list[num_ligatures] = 2; |
|
component_list[num_ligatures].set (second_glyph); |
|
num_ligatures++; |
|
} |
|
} |
|
|
|
if (!num_ligatures) |
|
return NULL; |
|
|
|
OT::Supplier<OT::GlyphID> first_glyphs_supplier (first_glyphs, num_first_glyphs); |
|
OT::Supplier<unsigned int > ligature_per_first_glyph_count_supplier (ligature_per_first_glyph_count_list, num_first_glyphs); |
|
OT::Supplier<OT::GlyphID> ligatures_supplier (ligature_list, num_ligatures); |
|
OT::Supplier<unsigned int > component_count_supplier (component_count_list, num_ligatures); |
|
OT::Supplier<OT::GlyphID> component_supplier (component_list, num_ligatures); |
|
|
|
/* 16 bytes per ligature ought to be enough... */ |
|
char buf[ARRAY_LENGTH_CONST (ligature_list) * 16 + 128]; |
|
OT::hb_serialize_context_t c (buf, sizeof (buf)); |
|
OT::SubstLookup *lookup = c.start_serialize<OT::SubstLookup> (); |
|
bool ret = lookup->serialize_ligature (&c, |
|
OT::LookupFlag::IgnoreMarks, |
|
first_glyphs_supplier, |
|
ligature_per_first_glyph_count_supplier, |
|
num_first_glyphs, |
|
ligatures_supplier, |
|
component_count_supplier, |
|
component_supplier); |
|
|
|
c.end_serialize (); |
|
/* TODO sanitize the results? */ |
|
|
|
return ret ? c.copy<OT::SubstLookup> () : NULL; |
|
} |
|
|
|
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 |
|
return arabic_fallback_synthesize_lookup_ligature (plan, font); |
|
} |
|
|
|
#define ARABIC_FALLBACK_MAX_LOOKUPS 5 |
|
|
|
struct arabic_fallback_plan_t |
|
{ |
|
ASSERT_POD (); |
|
|
|
unsigned int num_lookups; |
|
bool free_lookups; |
|
|
|
hb_mask_t mask_array[ARABIC_FALLBACK_MAX_LOOKUPS]; |
|
OT::SubstLookup *lookup_array[ARABIC_FALLBACK_MAX_LOOKUPS]; |
|
hb_ot_layout_lookup_accelerator_t accel_array[ARABIC_FALLBACK_MAX_LOOKUPS]; |
|
}; |
|
|
|
static const arabic_fallback_plan_t arabic_fallback_plan_nil = {}; |
|
|
|
#if (defined(_WIN32) || defined(__CYGWIN__)) && !defined(HB_NO_WIN1256) |
|
#define HB_WITH_WIN1256 |
|
#endif |
|
|
|
#ifdef HB_WITH_WIN1256 |
|
#include "hb-ot-shape-complex-arabic-win1256.hh" |
|
#endif |
|
|
|
struct ManifestLookup { |
|
OT::Tag tag; |
|
OT::OffsetTo<OT::SubstLookup> lookupOffset; |
|
}; |
|
typedef OT::ArrayOf<ManifestLookup> Manifest; |
|
|
|
static bool |
|
arabic_fallback_plan_init_win1256 (arabic_fallback_plan_t *fallback_plan, |
|
const hb_ot_shape_plan_t *plan, |
|
hb_font_t *font) |
|
{ |
|
#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); |
|
ASSERT_STATIC (sizeof (arabic_win1256_gsub_lookups.manifestData) / sizeof (ManifestLookup) |
|
<= ARABIC_FALLBACK_MAX_LOOKUPS); |
|
/* TODO sanitize the table? */ |
|
|
|
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].init (*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) |
|
{ |
|
ASSERT_STATIC (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].init (*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 *) calloc (1, sizeof (arabic_fallback_plan_t)); |
|
if (unlikely (!fallback_plan)) |
|
return const_cast<arabic_fallback_plan_t *> (&arabic_fallback_plan_nil); |
|
|
|
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; |
|
|
|
free (fallback_plan); |
|
return const_cast<arabic_fallback_plan_t *> (&arabic_fallback_plan_nil); |
|
} |
|
|
|
static void |
|
arabic_fallback_plan_destroy (arabic_fallback_plan_t *fallback_plan) |
|
{ |
|
if (!fallback_plan || fallback_plan == &arabic_fallback_plan_nil) |
|
return; |
|
|
|
for (unsigned int i = 0; i < fallback_plan->num_lookups; i++) |
|
if (fallback_plan->lookup_array[i]) |
|
{ |
|
fallback_plan->accel_array[i].fini (); |
|
if (fallback_plan->free_lookups) |
|
free (fallback_plan->lookup_array[i]); |
|
} |
|
|
|
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_apply_context_t c (0, font, buffer); |
|
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]); |
|
hb_ot_layout_substitute_lookup (&c, |
|
*fallback_plan->lookup_array[i], |
|
fallback_plan->accel_array[i]); |
|
} |
|
} |
|
|
|
|
|
#endif /* HB_OT_SHAPE_COMPLEX_ARABIC_FALLBACK_HH */
|
|
|