The Tor Browser: comparison gfx/harfbuzz/src/hb-ot-shape-complex-indic.cc

--1:000000000000
+:fd49cfdc1190
+/*
+* Copyright © 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.
+*
+* Google Author(s): Behdad Esfahbod
+*/
+#include "hb-ot-shape-complex-indic-private.hh"
+#include "hb-ot-layout-private.hh"
+/* buffer var allocations */
+#define indic_category() complex_var_u8_0() /* indic_category_t */
+#define indic_position() complex_var_u8_1() /* indic_position_t */
+/*
+* Indic shaper.
+*/
+#define IN_HALF_BLOCK(u, Base) (((u) & ~0x7F) == (Base))
+#define IS_DEVA(u) (IN_HALF_BLOCK (u, 0x0900))
+#define IS_BENG(u) (IN_HALF_BLOCK (u, 0x0980))
+#define IS_GURU(u) (IN_HALF_BLOCK (u, 0x0A00))
+#define IS_GUJR(u) (IN_HALF_BLOCK (u, 0x0A80))
+#define IS_ORYA(u) (IN_HALF_BLOCK (u, 0x0B00))
+#define IS_TAML(u) (IN_HALF_BLOCK (u, 0x0B80))
+#define IS_TELU(u) (IN_HALF_BLOCK (u, 0x0C00))
+#define IS_KNDA(u) (IN_HALF_BLOCK (u, 0x0C80))
+#define IS_MLYM(u) (IN_HALF_BLOCK (u, 0x0D00))
+#define IS_SINH(u) (IN_HALF_BLOCK (u, 0x0D80))
+#define IS_KHMR(u) (IN_HALF_BLOCK (u, 0x1780))
+#define MATRA_POS_LEFT(u)	POS_PRE_M
+#define MATRA_POS_RIGHT(u)	( \
+				  IS_DEVA(u) ? POS_AFTER_SUB  : \
+				  IS_BENG(u) ? POS_AFTER_POST : \
+				  IS_GURU(u) ? POS_AFTER_POST : \
+				  IS_GUJR(u) ? POS_AFTER_POST : \
+				  IS_ORYA(u) ? POS_AFTER_POST : \
+				  IS_TAML(u) ? POS_AFTER_POST : \
+				  IS_TELU(u) ? (u <= 0x0C42 ? POS_BEFORE_SUB : POS_AFTER_SUB) : \
+				  IS_KNDA(u) ? (u < 0x0CC3 || u > 0xCD6 ? POS_BEFORE_SUB : POS_AFTER_SUB) : \
+				  IS_MLYM(u) ? POS_AFTER_POST : \
+				  IS_SINH(u) ? POS_AFTER_SUB  : \
+				  IS_KHMR(u) ? POS_AFTER_POST : \
+				  /*default*/  POS_AFTER_SUB    \
+				)
+#define MATRA_POS_TOP(u)	( /* BENG and MLYM don't have top matras. */ \
+				  IS_DEVA(u) ? POS_AFTER_SUB  : \
+				  IS_GURU(u) ? POS_AFTER_POST : /* Deviate from spec */ \
+				  IS_GUJR(u) ? POS_AFTER_SUB  : \
+				  IS_ORYA(u) ? POS_AFTER_MAIN : \
+				  IS_TAML(u) ? POS_AFTER_SUB  : \
+				  IS_TELU(u) ? POS_BEFORE_SUB : \
+				  IS_KNDA(u) ? POS_BEFORE_SUB : \
+				  IS_SINH(u) ? POS_AFTER_SUB  : \
+				  IS_KHMR(u) ? POS_AFTER_POST : \
+				  /*default*/  POS_AFTER_SUB    \
+				)
+#define MATRA_POS_BOTTOM(u)	( \
+				  IS_DEVA(u) ? POS_AFTER_SUB  : \
+				  IS_BENG(u) ? POS_AFTER_SUB  : \
+				  IS_GURU(u) ? POS_AFTER_POST : \
+				  IS_GUJR(u) ? POS_AFTER_POST : \
+				  IS_ORYA(u) ? POS_AFTER_SUB  : \
+				  IS_TAML(u) ? POS_AFTER_POST : \
+				  IS_TELU(u) ? POS_BEFORE_SUB : \
+				  IS_KNDA(u) ? POS_BEFORE_SUB : \
+				  IS_MLYM(u) ? POS_AFTER_POST : \
+				  IS_SINH(u) ? POS_AFTER_SUB  : \
+				  IS_KHMR(u) ? POS_AFTER_POST : \
+				  /*default*/  POS_AFTER_SUB    \
+				)
+static inline indic_position_t
+matra_position (hb_codepoint_t u, indic_position_t side)
+{
+switch ((int) side)
+{
+case POS_PRE_C:	return MATRA_POS_LEFT (u);
+case POS_POST_C:	return MATRA_POS_RIGHT (u);
+case POS_ABOVE_C:	return MATRA_POS_TOP (u);
+case POS_BELOW_C:	return MATRA_POS_BOTTOM (u);
+};
+return side;
+}
+/* XXX
+* This is a hack for now.  We should move this data into the main Indic table.
+* Or completely remove it and just check in the tables.
+*/
+static const hb_codepoint_t ra_chars[] = {
+0x0930, /* Devanagari */
+0x09B0, /* Bengali */
+0x09F0, /* Bengali */
+0x0A30, /* Gurmukhi */	/* No Reph */
+0x0AB0, /* Gujarati */
+0x0B30, /* Oriya */
+0x0BB0, /* Tamil */		/* No Reph */
+0x0C30, /* Telugu */		/* Reph formed only with ZWJ */
+0x0CB0, /* Kannada */
+0x0D30, /* Malayalam */	/* No Reph, Logical Repha */
+0x0DBB, /* Sinhala */		/* Reph formed only with ZWJ */
+0x179A, /* Khmer */		/* No Reph, Visual Repha */
+};
+static inline bool
+is_ra (hb_codepoint_t u)
+{
+for (unsigned int i = 0; i < ARRAY_LENGTH (ra_chars); i++)
+if (u == ra_chars[i])
+return true;
+return false;
+}
+static inline bool
+is_one_of (const hb_glyph_info_t &info, unsigned int flags)
+{
+/* If it ligated, all bets are off. */
+if (_hb_glyph_info_ligated (&info)) return false;
+return !!(FLAG (info.indic_category()) & flags);
+}
+#define JOINER_FLAGS (FLAG (OT_ZWJ) | FLAG (OT_ZWNJ))
+static inline bool
+is_joiner (const hb_glyph_info_t &info)
+{
+return is_one_of (info, JOINER_FLAGS);
+}
+#define MEDIAL_FLAGS (FLAG (OT_CM) | FLAG (OT_CM2))
+/* Note:
+*
+* We treat Vowels and placeholders as if they were consonants.  This is safe because Vowels
+* cannot happen in a consonant syllable.  The plus side however is, we can call the
+* consonant syllable logic from the vowel syllable function and get it all right! */
+#define CONSONANT_FLAGS (FLAG (OT_C) | FLAG (OT_Ra) | MEDIAL_FLAGS | FLAG (OT_V) | FLAG (OT_NBSP) | FLAG (OT_DOTTEDCIRCLE))
+static inline bool
+is_consonant (const hb_glyph_info_t &info)
+{
+return is_one_of (info, CONSONANT_FLAGS);
+}
+#define HALANT_OR_COENG_FLAGS (FLAG (OT_H) | FLAG (OT_Coeng))
+static inline bool
+is_halant_or_coeng (const hb_glyph_info_t &info)
+{
+return is_one_of (info, HALANT_OR_COENG_FLAGS);
+}
+static inline void
+set_indic_properties (hb_glyph_info_t &info)
+{
+hb_codepoint_t u = info.codepoint;
+unsigned int type = hb_indic_get_categories (u);
+indic_category_t cat = (indic_category_t) (type & 0x7F);
+indic_position_t pos = (indic_position_t) (type >> 8);
+/*
+* Re-assign category
+*/
+/* The spec says U+0952 is OT_A.  However, testing shows that Uniscribe
+* treats U+0951..U+0954 all behave similarly.
+* TESTS:
+* U+092E,U+0947,U+0952
+* U+092E,U+0952,U+0947
+* U+092E,U+0947,U+0951
+* U+092E,U+0951,U+0947
+*/
+if (unlikely (hb_in_range<hb_codepoint_t> (u, 0x0951, 0x0954)))
+cat = OT_A;
+if (unlikely (u == 0x17D1))
+cat = OT_X;
+if (cat == OT_X &&
+unlikely (hb_in_range<hb_codepoint_t> (u, 0x17CB, 0x17D3))) /* Khmer Various signs */
+{
+/* These are like Top Matras. */
+cat = OT_M;
+pos = POS_ABOVE_C;
+}
+if (u == 0x17C6) /* Khmer Bindu doesn't like to be repositioned. */
+cat = OT_N;
+if (unlikely (u == 0x17D2)) cat = OT_Coeng; /* Khmer coeng */
+else if (unlikely (u == 0x200C)) cat = OT_ZWNJ;
+else if (unlikely (u == 0x200D)) cat = OT_ZWJ;
+else if (unlikely (u == 0x25CC)) cat = OT_DOTTEDCIRCLE;
+else if (unlikely (u == 0x0A71)) cat = OT_SM; /* GURMUKHI ADDAK.  Move it to the end. */
+else if (unlikely (u == 0xA982)) cat = OT_SM; /* Javanese repha. */
+else if (unlikely (u == 0xA9BE)) cat = OT_CM2; /* Javanese medial ya. */
+else if (unlikely (u == 0xA9BD)) { cat = OT_M; pos = POS_POST_C; } /* Javanese vocalic r. */
+if (cat == OT_Repha) {
+/* There are two kinds of characters marked as Repha:
+* - The ones that are GenCat=Mn are already positioned visually, ie. after base. (eg. Khmer)
+* - The ones that are GenCat=Lo is encoded logically, ie. beginning of syllable. (eg. Malayalam)
+*
+* We recategorize the first kind to look like a Nukta and attached to the base directly.
+*/
+if (_hb_glyph_info_get_general_category (&info) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)
+cat = OT_N;
+}
+/*
+* Re-assign position.
+*/
+if ((FLAG (cat) & CONSONANT_FLAGS))
+{
+pos = POS_BASE_C;
+if (is_ra (u))
+cat = OT_Ra;
+}
+else if (cat == OT_M)
+{
+pos = matra_position (u, pos);
+}
+else if ((FLAG (cat) & (FLAG (OT_SM) | FLAG (OT_VD) | FLAG (OT_A) | FLAG (OT_Avag))))
+{
+pos = POS_SMVD;
+}
+if (unlikely (u == 0x0B01)) pos = POS_BEFORE_SUB; /* Oriya Bindu is BeforeSub in the spec. */
+info.indic_category() = cat;
+info.indic_position() = pos;
+}
+/*
+* Things above this line should ideally be moved to the Indic table itself.
+*/
+/*
+* Indic configurations.  Note that we do not want to keep every single script-specific
+* behavior in these tables necessarily.  This should mainly be used for per-script
+* properties that are cheaper keeping here, than in the code.  Ie. if, say, one and
+* only one script has an exception, that one script can be if'ed directly in the code,
+* instead of adding a new flag in these structs.
+*/
+enum base_position_t {
+BASE_POS_FIRST,
+BASE_POS_LAST_SINHALA,
+BASE_POS_LAST
+};
+enum reph_position_t {
+REPH_POS_AFTER_MAIN  = POS_AFTER_MAIN,
+REPH_POS_BEFORE_SUB  = POS_BEFORE_SUB,
+REPH_POS_AFTER_SUB   = POS_AFTER_SUB,
+REPH_POS_BEFORE_POST = POS_BEFORE_POST,
+REPH_POS_AFTER_POST  = POS_AFTER_POST,
+REPH_POS_DONT_CARE   = POS_RA_TO_BECOME_REPH
+};
+enum reph_mode_t {
+REPH_MODE_IMPLICIT,  /* Reph formed out of initial Ra,H sequence. */
+REPH_MODE_EXPLICIT,  /* Reph formed out of initial Ra,H,ZWJ sequence. */
+REPH_MODE_VIS_REPHA, /* Encoded Repha character, no reordering needed. */
+REPH_MODE_LOG_REPHA  /* Encoded Repha character, needs reordering. */
+};
+enum blwf_mode_t {
+BLWF_MODE_PRE_AND_POST, /* Below-forms feature applied to pre-base and post-base. */
+BLWF_MODE_POST_ONLY     /* Below-forms feature applied to post-base only. */
+};
+enum pref_len_t {
+PREF_LEN_1 = 1,
+PREF_LEN_2 = 2,
+PREF_LEN_DONT_CARE = PREF_LEN_2
+};
+struct indic_config_t
+{
+hb_script_t     script;
+bool            has_old_spec;
+hb_codepoint_t  virama;
+base_position_t base_pos;
+reph_position_t reph_pos;
+reph_mode_t     reph_mode;
+blwf_mode_t     blwf_mode;
+pref_len_t      pref_len;
+};
+static const indic_config_t indic_configs[] =
+{
+/* Default.  Should be first. */
+{HB_SCRIPT_INVALID,	false,     0,BASE_POS_LAST, REPH_POS_BEFORE_POST,REPH_MODE_IMPLICIT, BLWF_MODE_PRE_AND_POST, PREF_LEN_1},
+{HB_SCRIPT_DEVANAGARI,true, 0x094D,BASE_POS_LAST, REPH_POS_BEFORE_POST,REPH_MODE_IMPLICIT, BLWF_MODE_PRE_AND_POST, PREF_LEN_DONT_CARE},
+{HB_SCRIPT_BENGALI,	true, 0x09CD,BASE_POS_LAST, REPH_POS_AFTER_SUB,  REPH_MODE_IMPLICIT, BLWF_MODE_PRE_AND_POST, PREF_LEN_DONT_CARE},
+{HB_SCRIPT_GURMUKHI,	true, 0x0A4D,BASE_POS_LAST, REPH_POS_BEFORE_SUB, REPH_MODE_IMPLICIT, BLWF_MODE_PRE_AND_POST, PREF_LEN_DONT_CARE},
+{HB_SCRIPT_GUJARATI,	true, 0x0ACD,BASE_POS_LAST, REPH_POS_BEFORE_POST,REPH_MODE_IMPLICIT, BLWF_MODE_PRE_AND_POST, PREF_LEN_DONT_CARE},
+{HB_SCRIPT_ORIYA,	true, 0x0B4D,BASE_POS_LAST, REPH_POS_AFTER_MAIN, REPH_MODE_IMPLICIT, BLWF_MODE_PRE_AND_POST, PREF_LEN_DONT_CARE},
+{HB_SCRIPT_TAMIL,	true, 0x0BCD,BASE_POS_LAST, REPH_POS_AFTER_POST, REPH_MODE_IMPLICIT, BLWF_MODE_PRE_AND_POST, PREF_LEN_2},
+{HB_SCRIPT_TELUGU,	true, 0x0C4D,BASE_POS_LAST, REPH_POS_AFTER_POST, REPH_MODE_EXPLICIT, BLWF_MODE_POST_ONLY,    PREF_LEN_2},
+{HB_SCRIPT_KANNADA,	true, 0x0CCD,BASE_POS_LAST, REPH_POS_AFTER_POST, REPH_MODE_IMPLICIT, BLWF_MODE_POST_ONLY,    PREF_LEN_2},
+{HB_SCRIPT_MALAYALAM,	true, 0x0D4D,BASE_POS_LAST, REPH_POS_AFTER_MAIN, REPH_MODE_LOG_REPHA,BLWF_MODE_PRE_AND_POST, PREF_LEN_2},
+{HB_SCRIPT_SINHALA,	false,0x0DCA,BASE_POS_LAST_SINHALA,
+						    REPH_POS_AFTER_MAIN, REPH_MODE_EXPLICIT, BLWF_MODE_PRE_AND_POST, PREF_LEN_DONT_CARE},
+{HB_SCRIPT_KHMER,	false,0x17D2,BASE_POS_FIRST,REPH_POS_DONT_CARE,  REPH_MODE_VIS_REPHA,BLWF_MODE_PRE_AND_POST, PREF_LEN_2},
+{HB_SCRIPT_JAVANESE,	false,0xA9C0,BASE_POS_FIRST,REPH_POS_DONT_CARE,  REPH_MODE_VIS_REPHA,BLWF_MODE_PRE_AND_POST, PREF_LEN_1},
+};
+/*
+* Indic shaper.
+*/
+struct feature_list_t {
+hb_tag_t tag;
+hb_ot_map_feature_flags_t flags;
+};
+static const feature_list_t
+indic_features[] =
+{
+/*
+* Basic features.
+* These features are applied in order, one at a time, after initial_reordering.
+*/
+{HB_TAG('n','u','k','t'), F_GLOBAL},
+{HB_TAG('a','k','h','n'), F_GLOBAL},
+{HB_TAG('r','p','h','f'), F_NONE},
+{HB_TAG('r','k','r','f'), F_GLOBAL},
+{HB_TAG('p','r','e','f'), F_NONE},
+{HB_TAG('b','l','w','f'), F_NONE},
+{HB_TAG('a','b','v','f'), F_NONE},
+{HB_TAG('h','a','l','f'), F_NONE},
+{HB_TAG('p','s','t','f'), F_NONE},
+{HB_TAG('v','a','t','u'), F_GLOBAL},
+{HB_TAG('c','j','c','t'), F_GLOBAL},
+{HB_TAG('c','f','a','r'), F_NONE},
+/*
+* Other features.
+* These features are applied all at once, after final_reordering.
+* Default Bengali font in Windows for example has intermixed
+* lookups for init,pres,abvs,blws features.
+*/
+{HB_TAG('i','n','i','t'), F_NONE},
+{HB_TAG('p','r','e','s'), F_GLOBAL},
+{HB_TAG('a','b','v','s'), F_GLOBAL},
+{HB_TAG('b','l','w','s'), F_GLOBAL},
+{HB_TAG('p','s','t','s'), F_GLOBAL},
+{HB_TAG('h','a','l','n'), F_GLOBAL},
+/* Positioning features, though we don't care about the types. */
+{HB_TAG('d','i','s','t'), F_GLOBAL},
+{HB_TAG('a','b','v','m'), F_GLOBAL},
+{HB_TAG('b','l','w','m'), F_GLOBAL},
+};
+/*
+* Must be in the same order as the indic_features array.
+*/
+enum {
+_NUKT,
+_AKHN,
+RPHF,
+_RKRF,
+PREF,
+BLWF,
+ABVF,
+HALF,
+PSTF,
+_VATU,
+_CJCT,
+CFAR,
+INIT,
+_PRES,
+_ABVS,
+_BLWS,
+_PSTS,
+_HALN,
+_DIST,
+_ABVM,
+_BLWM,
+INDIC_NUM_FEATURES,
+INDIC_BASIC_FEATURES = INIT /* Don't forget to update this! */
+};
+static void
+setup_syllables (const hb_ot_shape_plan_t *plan,
+		 hb_font_t *font,
+		 hb_buffer_t *buffer);
+static void
+initial_reordering (const hb_ot_shape_plan_t *plan,
+		    hb_font_t *font,
+		    hb_buffer_t *buffer);
+static void
+final_reordering (const hb_ot_shape_plan_t *plan,
+		  hb_font_t *font,
+		  hb_buffer_t *buffer);
+static void
+clear_syllables (const hb_ot_shape_plan_t *plan,
+		 hb_font_t *font,
+		 hb_buffer_t *buffer);
+static void
+collect_features_indic (hb_ot_shape_planner_t *plan)
+{
+hb_ot_map_builder_t *map = &plan->map;
+/* Do this before any lookups have been applied. */
+map->add_gsub_pause (setup_syllables);
+map->add_global_bool_feature (HB_TAG('l','o','c','l'));
+/* The Indic specs do not require ccmp, but we apply it here since if
+* there is a use of it, it's typically at the beginning. */
+map->add_global_bool_feature (HB_TAG('c','c','m','p'));
+unsigned int i = 0;
+map->add_gsub_pause (initial_reordering);
+for (; i < INDIC_BASIC_FEATURES; i++) {
+map->add_feature (indic_features[i].tag, 1, indic_features[i].flags | F_MANUAL_ZWJ);
+map->add_gsub_pause (NULL);
+}
+map->add_gsub_pause (final_reordering);
+for (; i < INDIC_NUM_FEATURES; i++) {
+map->add_feature (indic_features[i].tag, 1, indic_features[i].flags | F_MANUAL_ZWJ);
+}
+map->add_global_bool_feature (HB_TAG('c','a','l','t'));
+map->add_global_bool_feature (HB_TAG('c','l','i','g'));
+map->add_gsub_pause (clear_syllables);
+}
+static void
+override_features_indic (hb_ot_shape_planner_t *plan)
+{
+/* Uniscribe does not apply 'kern' in Khmer. */
+if (hb_options ().uniscribe_bug_compatible)
+{
+switch ((hb_tag_t) plan->props.script)
+{
+case HB_SCRIPT_KHMER:
+	plan->map.add_feature (HB_TAG('k','e','r','n'), 0, F_GLOBAL);
+	break;
+}
+}
+plan->map.add_feature (HB_TAG('l','i','g','a'), 0, F_GLOBAL);
+}
+struct would_substitute_feature_t
+{
+inline void init (const hb_ot_map_t *map, hb_tag_t feature_tag, bool zero_context_)
+{
+zero_context = zero_context_;
+map->get_stage_lookups (0/*GSUB*/,
+			    map->get_feature_stage (0/*GSUB*/, feature_tag),
+			    &lookups, &count);
+}
+inline bool would_substitute (const hb_codepoint_t *glyphs,
+				unsigned int          glyphs_count,
+				hb_face_t            *face) const
+{
+for (unsigned int i = 0; i < count; i++)
+if (hb_ot_layout_lookup_would_substitute_fast (face, lookups[i].index, glyphs, glyphs_count, zero_context))
+	return true;
+return false;
+}
+private:
+const hb_ot_map_t::lookup_map_t *lookups;
+unsigned int count;
+bool zero_context;
+};
+struct indic_shape_plan_t
+{
+ASSERT_POD ();
+inline bool get_virama_glyph (hb_font_t *font, hb_codepoint_t *pglyph) const
+{
+hb_codepoint_t glyph = virama_glyph;
+if (unlikely (virama_glyph == (hb_codepoint_t) -1))
+{
+if (!config->virama || !font->get_glyph (config->virama, 0, &glyph))
+	glyph = 0;
+/* Technically speaking, the spec says we should apply 'locl' to virama too.
+* Maybe one day... */
+/* Our get_glyph() function needs a font, so we can't get the virama glyph
+* during shape planning...  Instead, overwrite it here.  It's safe.  Don't worry! */
+(const_cast<indic_shape_plan_t *> (this))->virama_glyph = glyph;
+}
+*pglyph = glyph;
+return glyph != 0;
+}
+const indic_config_t *config;
+bool is_old_spec;
+hb_codepoint_t virama_glyph;
+would_substitute_feature_t rphf;
+would_substitute_feature_t pref;
+would_substitute_feature_t blwf;
+would_substitute_feature_t pstf;
+hb_mask_t mask_array[INDIC_NUM_FEATURES];
+};
+static void *
+data_create_indic (const hb_ot_shape_plan_t *plan)
+{
+indic_shape_plan_t *indic_plan = (indic_shape_plan_t *) calloc (1, sizeof (indic_shape_plan_t));
+if (unlikely (!indic_plan))
+return NULL;
+indic_plan->config = &indic_configs[0];
+for (unsigned int i = 1; i < ARRAY_LENGTH (indic_configs); i++)
+if (plan->props.script == indic_configs[i].script) {
+indic_plan->config = &indic_configs[i];
+break;
+}
+indic_plan->is_old_spec = indic_plan->config->has_old_spec && ((plan->map.chosen_script[0] & 0x000000FF) != '2');
+indic_plan->virama_glyph = (hb_codepoint_t) -1;
+/* Use zero-context would_substitute() matching for new-spec of the main
+* Indic scripts, but not for old-spec or scripts with one spec only. */
+bool zero_context = indic_plan->config->has_old_spec || !indic_plan->is_old_spec;
+indic_plan->rphf.init (&plan->map, HB_TAG('r','p','h','f'), zero_context);
+indic_plan->pref.init (&plan->map, HB_TAG('p','r','e','f'), zero_context);
+indic_plan->blwf.init (&plan->map, HB_TAG('b','l','w','f'), zero_context);
+indic_plan->pstf.init (&plan->map, HB_TAG('p','s','t','f'), zero_context);
+for (unsigned int i = 0; i < ARRAY_LENGTH (indic_plan->mask_array); i++)
+indic_plan->mask_array[i] = (indic_features[i].flags & F_GLOBAL) ?
+				 0 : plan->map.get_1_mask (indic_features[i].tag);
+return indic_plan;
+}
+static void
+data_destroy_indic (void *data)
+{
+free (data);
+}
+static indic_position_t
+consonant_position_from_face (const indic_shape_plan_t *indic_plan,
+			      const hb_codepoint_t consonant,
+			      const hb_codepoint_t virama,
+			      hb_face_t *face)
+{
+/* For old-spec, the order of glyphs is Consonant,Virama,
+* whereas for new-spec, it's Virama,Consonant.  However,
+* some broken fonts (like Free Sans) simply copied lookups
+* from old-spec to new-spec without modification.
+* And oddly enough, Uniscribe seems to respect those lookups.
+* Eg. in the sequence U+0924,U+094D,U+0930, Uniscribe finds
+* base at 0.  The font however, only has lookups matching
+* 930,94D in 'blwf', not the expected 94D,930 (with new-spec
+* table).  As such, we simply match both sequences.  Seems
+* to work. */
+hb_codepoint_t glyphs[3] = {virama, consonant, virama};
+if (indic_plan->blwf.would_substitute (glyphs  , 2, face) ||
+indic_plan->blwf.would_substitute (glyphs+1, 2, face))
+return POS_BELOW_C;
+if (indic_plan->pstf.would_substitute (glyphs  , 2, face) ||
+indic_plan->pstf.would_substitute (glyphs+1, 2, face))
+return POS_POST_C;
+unsigned int pref_len = indic_plan->config->pref_len;
+if ((pref_len == PREF_LEN_2 &&
+(indic_plan->pref.would_substitute (glyphs  , 2, face) ||
+indic_plan->pref.would_substitute (glyphs+1, 2, face)))
+|| (pref_len == PREF_LEN_1 &&
+indic_plan->pref.would_substitute (glyphs+1, 1, face)))
+return POS_POST_C;
+return POS_BASE_C;
+}
+enum syllable_type_t {
+consonant_syllable,
+vowel_syllable,
+standalone_cluster,
+avagraha_cluster,
+broken_cluster,
+non_indic_cluster,
+};
+#include "hb-ot-shape-complex-indic-machine.hh"
+static void
+setup_masks_indic (const hb_ot_shape_plan_t *plan HB_UNUSED,
+		   hb_buffer_t              *buffer,
+		   hb_font_t                *font HB_UNUSED)
+{
+HB_BUFFER_ALLOCATE_VAR (buffer, indic_category);
+HB_BUFFER_ALLOCATE_VAR (buffer, indic_position);
+/* We cannot setup masks here.  We save information about characters
+* and setup masks later on in a pause-callback. */
+unsigned int count = buffer->len;
+for (unsigned int i = 0; i < count; i++)
+set_indic_properties (buffer->info[i]);
+}
+static void
+setup_syllables (const hb_ot_shape_plan_t *plan HB_UNUSED,
+		 hb_font_t *font HB_UNUSED,
+		 hb_buffer_t *buffer)
+{
+find_syllables (buffer);
+}
+static int
+compare_indic_order (const hb_glyph_info_t *pa, const hb_glyph_info_t *pb)
+{
+int a = pa->indic_position();
+int b = pb->indic_position();
+return a < b ? -1 : a == b ? 0 : +1;
+}
+static void
+update_consonant_positions (const hb_ot_shape_plan_t *plan,
+			    hb_font_t         *font,
+			    hb_buffer_t       *buffer)
+{
+const indic_shape_plan_t *indic_plan = (const indic_shape_plan_t *) plan->data;
+if (indic_plan->config->base_pos != BASE_POS_LAST)
+return;
+hb_codepoint_t virama;
+if (indic_plan->get_virama_glyph (font, &virama))
+{
+hb_face_t *face = font->face;
+unsigned int count = buffer->len;
+for (unsigned int i = 0; i < count; i++)
+if (buffer->info[i].indic_position() == POS_BASE_C) {
+	hb_codepoint_t consonant = buffer->info[i].codepoint;
+	buffer->info[i].indic_position() = consonant_position_from_face (indic_plan, consonant, virama, face);
+}
+}
+}
+/* Rules from:
+* https://www.microsoft.com/typography/otfntdev/devanot/shaping.aspx */
+static void
+initial_reordering_consonant_syllable (const hb_ot_shape_plan_t *plan,
+				       hb_face_t *face,
+				       hb_buffer_t *buffer,
+				       unsigned int start, unsigned int end)
+{
+const indic_shape_plan_t *indic_plan = (const indic_shape_plan_t *) plan->data;
+hb_glyph_info_t *info = buffer->info;
+/* 1. Find base consonant:
+*
+* The shaping engine finds the base consonant of the syllable, using the
+* following algorithm: starting from the end of the syllable, move backwards
+* until a consonant is found that does not have a below-base or post-base
+* form (post-base forms have to follow below-base forms), or that is not a
+* pre-base reordering Ra, or arrive at the first consonant. The consonant
+* stopped at will be the base.
+*
+*   o If the syllable starts with Ra + Halant (in a script that has Reph)
+*     and has more than one consonant, Ra is excluded from candidates for
+*     base consonants.
+*/
+unsigned int base = end;
+bool has_reph = false;
+{
+/* -> If the syllable starts with Ra + Halant (in a script that has Reph)
+*    and has more than one consonant, Ra is excluded from candidates for
+*    base consonants. */
+unsigned int limit = start;
+if (indic_plan->config->reph_pos != REPH_POS_DONT_CARE &&
+	indic_plan->mask_array[RPHF] &&
+	start + 3 <= end &&
+	(
+	 (indic_plan->config->reph_mode == REPH_MODE_IMPLICIT && !is_joiner (info[start + 2])) ||
+	 (indic_plan->config->reph_mode == REPH_MODE_EXPLICIT && info[start + 2].indic_category() == OT_ZWJ)
+	))
+{
+/* See if it matches the 'rphf' feature. */
+hb_codepoint_t glyphs[2] = {info[start].codepoint, info[start + 1].codepoint};
+if (indic_plan->rphf.would_substitute (glyphs, ARRAY_LENGTH (glyphs), face))
+{
+	limit += 2;
+	while (limit < end && is_joiner (info[limit]))
+	  limit++;
+	base = start;
+	has_reph = true;
+}
+} else if (indic_plan->config->reph_mode == REPH_MODE_LOG_REPHA && info[start].indic_category() == OT_Repha)
+{
+	limit += 1;
+	while (limit < end && is_joiner (info[limit]))
+	  limit++;
+	base = start;
+	has_reph = true;
+}
+switch (indic_plan->config->base_pos)
+{
+default:
+assert (false);
+	/* fallthrough */
+case BASE_POS_LAST:
+{
+	/* -> starting from the end of the syllable, move backwards */
+	unsigned int i = end;
+	bool seen_below = false;
+	do {
+	  i--;
+	  /* -> until a consonant is found */
+	  if (is_consonant (info[i]))
+	  {
+	    /* -> that does not have a below-base or post-base form
+	     * (post-base forms have to follow below-base forms), */
+	    if (info[i].indic_position() != POS_BELOW_C &&
+		(info[i].indic_position() != POS_POST_C || seen_below))
+	    {
+	      base = i;
+	      break;
+	    }
+	    if (info[i].indic_position() == POS_BELOW_C)
+	      seen_below = true;
+	    /* -> or that is not a pre-base reordering Ra,
+	     *
+	     * IMPLEMENTATION NOTES:
+	     *
+	     * Our pre-base reordering Ra's are marked POS_POST_C, so will be skipped
+	     * by the logic above already.
+	     */
+	    /* -> or arrive at the first consonant. The consonant stopped at will
+	     * be the base. */
+	    base = i;
+	  }
+	  else
+	  {
+	    /* A ZWJ after a Halant stops the base search, and requests an explicit
+	     * half form.
+	     * A ZWJ before a Halant, requests a subjoined form instead, and hence
+	     * search continues.  This is particularly important for Bengali
+	     * sequence Ra,H,Ya that should form Ya-Phalaa by subjoining Ya. */
+	    if (start < i &&
+		info[i].indic_category() == OT_ZWJ &&
+		info[i - 1].indic_category() == OT_H)
+	      break;
+	  }
+	} while (i > limit);
+}
+break;
+case BASE_POS_LAST_SINHALA:
+{
+/* Sinhala base positioning is slightly different from main Indic, in that:
+	 * 1. It's ZWJ behavior is different,
+	 * 2. We don't need to look into the font for consonant positions.
+	 */
+	if (!has_reph)
+	  base = limit;
+	/* Find the last base consonant that is not blocked by ZWJ.  If there is
+	 * a ZWJ right before a base consonant, that would request a subjoined form. */
+	for (unsigned int i = limit; i < end; i++)
+	  if (is_consonant (info[i]))
+	  {
+	    if (limit < i && info[i - 1].indic_category() == OT_ZWJ)
+	      break;
+	    else
+	      base = i;
+	  }
+	/* Mark all subsequent consonants as below. */
+	for (unsigned int i = base + 1; i < end; i++)
+	  if (is_consonant (info[i]))
+	    info[i].indic_position() = POS_BELOW_C;
+}
+break;
+case BASE_POS_FIRST:
+{
+	/* The first consonant is always the base. */
+	assert (indic_plan->config->reph_mode == REPH_MODE_VIS_REPHA);
+	assert (!has_reph);
+	base = start;
+	/* Mark all subsequent consonants as below. */
+	for (unsigned int i = base + 1; i < end; i++)
+	  if (is_consonant (info[i]))
+	    info[i].indic_position() = POS_BELOW_C;
+}
+break;
+}
+/* -> If the syllable starts with Ra + Halant (in a script that has Reph)
+*    and has more than one consonant, Ra is excluded from candidates for
+*    base consonants.
+*
+*  Only do this for unforced Reph. (ie. not for Ra,H,ZWJ. */
+if (has_reph && base == start && limit - base <= 2) {
+/* Have no other consonant, so Reph is not formed and Ra becomes base. */
+has_reph = false;
+}
+}
+/* 2. Decompose and reorder Matras:
+*
+* Each matra and any syllable modifier sign in the cluster are moved to the
+* appropriate position relative to the consonant(s) in the cluster. The
+* shaping engine decomposes two- or three-part matras into their constituent
+* parts before any repositioning. Matra characters are classified by which
+* consonant in a conjunct they have affinity for and are reordered to the
+* following positions:
+*
+*   o Before first half form in the syllable
+*   o After subjoined consonants
+*   o After post-form consonant
+*   o After main consonant (for above marks)
+*
+* IMPLEMENTATION NOTES:
+*
+* The normalize() routine has already decomposed matras for us, so we don't
+* need to worry about that.
+*/
+/* 3.  Reorder marks to canonical order:
+*
+* Adjacent nukta and halant or nukta and vedic sign are always repositioned
+* if necessary, so that the nukta is first.
+*
+* IMPLEMENTATION NOTES:
+*
+* We don't need to do this: the normalize() routine already did this for us.
+*/
+/* Reorder characters */
+for (unsigned int i = start; i < base; i++)
+info[i].indic_position() = MIN (POS_PRE_C, (indic_position_t) info[i].indic_position());
+if (base < end)
+info[base].indic_position() = POS_BASE_C;
+/* Mark final consonants.  A final consonant is one appearing after a matra,
+* like in Khmer. */
+for (unsigned int i = base + 1; i < end; i++)
+if (info[i].indic_category() == OT_M) {
+for (unsigned int j = i + 1; j < end; j++)
+if (is_consonant (info[j])) {
+	  info[j].indic_position() = POS_FINAL_C;
+	  break;
+	}
+break;
+}
+/* Handle beginning Ra */
+if (has_reph)
+info[start].indic_position() = POS_RA_TO_BECOME_REPH;
+/* For old-style Indic script tags, move the first post-base Halant after
+* last consonant.  Only do this if there is *not* a Halant after last
+* consonant.  Otherwise it becomes messy. */
+if (indic_plan->is_old_spec) {
+for (unsigned int i = base + 1; i < end; i++)
+if (info[i].indic_category() == OT_H) {
+unsigned int j;
+for (j = end - 1; j > i; j--)
+	  if (is_consonant (info[j]) || info[j].indic_category() == OT_H)
+	    break;
+	if (info[j].indic_category() != OT_H && j > i) {
+	  /* Move Halant to after last consonant. */
+	  hb_glyph_info_t t = info[i];
+	  memmove (&info[i], &info[i + 1], (j - i) * sizeof (info[0]));
+	  info[j] = t;
+	}
+break;
+}
+}
+/* Attach misc marks to previous char to move with them. */
+{
+indic_position_t last_pos = POS_START;
+for (unsigned int i = start; i < end; i++)
+{
+if ((FLAG (info[i].indic_category()) & (JOINER_FLAGS | FLAG (OT_N) | FLAG (OT_RS) | MEDIAL_FLAGS | HALANT_OR_COENG_FLAGS)))
+{
+	info[i].indic_position() = last_pos;
+	if (unlikely (info[i].indic_category() == OT_H &&
+		      info[i].indic_position() == POS_PRE_M))
+	{
+	  /*
+	   * Uniscribe doesn't move the Halant with Left Matra.
+	   * TEST: U+092B,U+093F,U+094DE
+	   * We follow.  This is important for the Sinhala
+	   * U+0DDA split matra since it decomposes to U+0DD9,U+0DCA
+	   * where U+0DD9 is a left matra and U+0DCA is the virama.
+	   * We don't want to move the virama with the left matra.
+	   * TEST: U+0D9A,U+0DDA
+	   */
+	  for (unsigned int j = i; j > start; j--)
+	    if (info[j - 1].indic_position() != POS_PRE_M) {
+	      info[i].indic_position() = info[j - 1].indic_position();
+	      break;
+	    }
+	}
+} else if (info[i].indic_position() != POS_SMVD) {
+last_pos = (indic_position_t) info[i].indic_position();
+}
+}
+}
+/* For post-base consonants let them own anything before them
+* since the last consonant or matra. */
+{
+unsigned int last = base;
+for (unsigned int i = base + 1; i < end; i++)
+if (is_consonant (info[i]))
+{
+	for (unsigned int j = last + 1; j < i; j++)
+	  if (info[j].indic_position() < POS_SMVD)
+	    info[j].indic_position() = info[i].indic_position();
+	last = i;
+} else if (info[i].indic_category() == OT_M)
+last = i;
+}
+{
+/* Use syllable() for sort accounting temporarily. */
+unsigned int syllable = info[start].syllable();
+for (unsigned int i = start; i < end; i++)
+info[i].syllable() = i - start;
+/* Sit tight, rock 'n roll! */
+hb_bubble_sort (info + start, end - start, compare_indic_order);
+/* Find base again */
+base = end;
+for (unsigned int i = start; i < end; i++)
+if (info[i].indic_position() == POS_BASE_C)
+{
+	base = i;
+	break;
+}
+/* Things are out-of-control for post base positions, they may shuffle
+* around like crazy.  In old-spec mode, we move halants around, so in
+* that case merge all clusters after base.  Otherwise, check the sort
+* order and merge as needed.
+* For pre-base stuff, we handle cluster issues in final reordering. */
+if (indic_plan->is_old_spec || end - base > 127)
+buffer->merge_clusters (base, end);
+else
+{
+/* Note!  syllable() is a one-byte field. */
+for (unsigned int i = base; i < end; i++)
+if (info[i].syllable() != 255)
+	{
+	  unsigned int max = i;
+	  unsigned int j = start + info[i].syllable();
+	  while (j != i)
+	  {
+	    max = MAX (max, j);
+	    unsigned int next = start + info[j].syllable();
+	    info[j].syllable() = 255; /* So we don't process j later again. */
+	    j = next;
+	  }
+	  if (i != max)
+	    buffer->merge_clusters (i, max + 1);
+	}
+}
+/* Put syllable back in. */
+for (unsigned int i = start; i < end; i++)
+info[i].syllable() = syllable;
+}
+/* Setup masks now */
+{
+hb_mask_t mask;
+/* Reph */
+for (unsigned int i = start; i < end && info[i].indic_position() == POS_RA_TO_BECOME_REPH; i++)
+info[i].mask |= indic_plan->mask_array[RPHF];
+/* Pre-base */
+mask = indic_plan->mask_array[HALF];
+if (!indic_plan->is_old_spec &&
+	indic_plan->config->blwf_mode == BLWF_MODE_PRE_AND_POST)
+mask |= indic_plan->mask_array[BLWF];
+for (unsigned int i = start; i < base; i++)
+info[i].mask  |= mask;
+/* Base */
+mask = 0;
+if (base < end)
+info[base].mask |= mask;
+/* Post-base */
+mask = indic_plan->mask_array[BLWF] | indic_plan->mask_array[ABVF] | indic_plan->mask_array[PSTF];
+for (unsigned int i = base + 1; i < end; i++)
+info[i].mask  |= mask;
+}
+if (indic_plan->is_old_spec &&
+buffer->props.script == HB_SCRIPT_DEVANAGARI)
+{
+/* Old-spec eye-lash Ra needs special handling.  From the
+* spec:
+*
+* "The feature 'below-base form' is applied to consonants
+* having below-base forms and following the base consonant.
+* The exception is vattu, which may appear below half forms
+* as well as below the base glyph. The feature 'below-base
+* form' will be applied to all such occurrences of Ra as well."
+*
+* Test case: U+0924,U+094D,U+0930,U+094d,U+0915
+* with Sanskrit 2003 font.
+*
+* However, note that Ra,Halant,ZWJ is the correct way to
+* request eyelash form of Ra, so we wouldbn't inhibit it
+* in that sequence.
+*
+* Test case: U+0924,U+094D,U+0930,U+094d,U+200D,U+0915
+*/
+for (unsigned int i = start; i + 1 < base; i++)
+if (info[i  ].indic_category() == OT_Ra &&
+	  info[i+1].indic_category() == OT_H  &&
+	  (i + 2 == base ||
+	   info[i+2].indic_category() != OT_ZWJ))
+{
+	info[i  ].mask |= indic_plan->mask_array[BLWF];
+	info[i+1].mask |= indic_plan->mask_array[BLWF];
+}
+}
+unsigned int pref_len = indic_plan->config->pref_len;
+if (indic_plan->mask_array[PREF] && base + pref_len < end)
+{
+assert (1 <= pref_len && pref_len <= 2);
+/* Find a Halant,Ra sequence and mark it for pre-base reordering processing. */
+for (unsigned int i = base + 1; i + pref_len - 1 < end; i++) {
+hb_codepoint_t glyphs[2];
+for (unsigned int j = 0; j < pref_len; j++)
+glyphs[j] = info[i + j].codepoint;
+if (indic_plan->pref.would_substitute (glyphs, pref_len, face))
+{
+	for (unsigned int j = 0; j < pref_len; j++)
+	  info[i++].mask |= indic_plan->mask_array[PREF];
+	/* Mark the subsequent stuff with 'cfar'.  Used in Khmer.
+	 * Read the feature spec.
+	 * This allows distinguishing the following cases with MS Khmer fonts:
+	 * U+1784,U+17D2,U+179A,U+17D2,U+1782
+	 * U+1784,U+17D2,U+1782,U+17D2,U+179A
+	 */
+	if (indic_plan->mask_array[CFAR])
+	  for (; i < end; i++)
+	    info[i].mask |= indic_plan->mask_array[CFAR];
+	break;
+}
+}
+}
+/* Apply ZWJ/ZWNJ effects */
+for (unsigned int i = start + 1; i < end; i++)
+if (is_joiner (info[i])) {
+bool non_joiner = info[i].indic_category() == OT_ZWNJ;
+unsigned int j = i;
+do {
+	j--;
+	/* ZWJ/ZWNJ should disable CJCT.  They do that by simply
+	 * being there, since we don't skip them for the CJCT
+	 * feature (ie. F_MANUAL_ZWJ) */
+	/* A ZWNJ disables HALF. */
+	if (non_joiner)
+	  info[j].mask &= ~indic_plan->mask_array[HALF];
+} while (j > start && !is_consonant (info[j]));
+}
+}
+static void
+initial_reordering_vowel_syllable (const hb_ot_shape_plan_t *plan,
+				   hb_face_t *face,
+				   hb_buffer_t *buffer,
+				   unsigned int start, unsigned int end)
+{
+/* We made the vowels look like consonants.  So let's call the consonant logic! */
+initial_reordering_consonant_syllable (plan, face, buffer, start, end);
+}
+static void
+initial_reordering_standalone_cluster (const hb_ot_shape_plan_t *plan,
+				       hb_face_t *face,
+				       hb_buffer_t *buffer,
+				       unsigned int start, unsigned int end)
+{
+/* We treat NBSP/dotted-circle as if they are consonants, so we should just chain.
+* Only if not in compatibility mode that is... */
+if (hb_options ().uniscribe_bug_compatible)
+{
+/* For dotted-circle, this is what Uniscribe does:
+* If dotted-circle is the last glyph, it just does nothing.
+* Ie. It doesn't form Reph. */
+if (buffer->info[end - 1].indic_category() == OT_DOTTEDCIRCLE)
+return;
+}
+initial_reordering_consonant_syllable (plan, face, buffer, start, end);
+}
+static void
+initial_reordering_broken_cluster (const hb_ot_shape_plan_t *plan,
+				   hb_face_t *face,
+				   hb_buffer_t *buffer,
+				   unsigned int start, unsigned int end)
+{
+/* We already inserted dotted-circles, so just call the standalone_cluster. */
+initial_reordering_standalone_cluster (plan, face, buffer, start, end);
+}
+static void
+initial_reordering_avagraha_cluster (const hb_ot_shape_plan_t *plan HB_UNUSED,
+				     hb_face_t *face HB_UNUSED,
+				     hb_buffer_t *buffer HB_UNUSED,
+				     unsigned int start HB_UNUSED, unsigned int end HB_UNUSED)
+{
+/* Nothing to do right now.  If we ever switch to using the output
+* buffer in the reordering process, we'd need to next_glyph() here. */
+}
+static void
+initial_reordering_non_indic_cluster (const hb_ot_shape_plan_t *plan HB_UNUSED,
+				      hb_face_t *face HB_UNUSED,
+				      hb_buffer_t *buffer HB_UNUSED,
+				      unsigned int start HB_UNUSED, unsigned int end HB_UNUSED)
+{
+/* Nothing to do right now.  If we ever switch to using the output
+* buffer in the reordering process, we'd need to next_glyph() here. */
+}
+static void
+initial_reordering_syllable (const hb_ot_shape_plan_t *plan,
+			     hb_face_t *face,
+			     hb_buffer_t *buffer,
+			     unsigned int start, unsigned int end)
+{
+syllable_type_t syllable_type = (syllable_type_t) (buffer->info[start].syllable() & 0x0F);
+switch (syllable_type) {
+case consonant_syllable:	initial_reordering_consonant_syllable (plan, face, buffer, start, end); return;
+case vowel_syllable:		initial_reordering_vowel_syllable     (plan, face, buffer, start, end); return;
+case standalone_cluster:	initial_reordering_standalone_cluster (plan, face, buffer, start, end); return;
+case avagraha_cluster:	initial_reordering_avagraha_cluster   (plan, face, buffer, start, end); return;
+case broken_cluster:		initial_reordering_broken_cluster     (plan, face, buffer, start, end); return;
+case non_indic_cluster:	initial_reordering_non_indic_cluster  (plan, face, buffer, start, end); return;
+}
+}
+static inline void
+insert_dotted_circles (const hb_ot_shape_plan_t *plan HB_UNUSED,
+		       hb_font_t *font,
+		       hb_buffer_t *buffer)
+{
+/* Note: This loop is extra overhead, but should not be measurable. */
+bool has_broken_syllables = false;
+unsigned int count = buffer->len;
+for (unsigned int i = 0; i < count; i++)
+if ((buffer->info[i].syllable() & 0x0F) == broken_cluster) {
+has_broken_syllables = true;
+break;
+}
+if (likely (!has_broken_syllables))
+return;
+hb_codepoint_t dottedcircle_glyph;
+if (!font->get_glyph (0x25CC, 0, &dottedcircle_glyph))
+return;
+hb_glyph_info_t dottedcircle = {0};
+dottedcircle.codepoint = 0x25CC;
+set_indic_properties (dottedcircle);
+dottedcircle.codepoint = dottedcircle_glyph;
+buffer->clear_output ();
+buffer->idx = 0;
+unsigned int last_syllable = 0;
+while (buffer->idx < buffer->len)
+{
+unsigned int syllable = buffer->cur().syllable();
+syllable_type_t syllable_type = (syllable_type_t) (syllable & 0x0F);
+if (unlikely (last_syllable != syllable && syllable_type == broken_cluster))
+{
+last_syllable = syllable;
+hb_glyph_info_t info = dottedcircle;
+info.cluster = buffer->cur().cluster;
+info.mask = buffer->cur().mask;
+info.syllable() = buffer->cur().syllable();
+/* Insert dottedcircle after possible Repha. */
+while (buffer->idx < buffer->len &&
+	     last_syllable == buffer->cur().syllable() &&
+	     buffer->cur().indic_category() == OT_Repha)
+buffer->next_glyph ();
+buffer->output_info (info);
+}
+else
+buffer->next_glyph ();
+}
+buffer->swap_buffers ();
+}
+static void
+initial_reordering (const hb_ot_shape_plan_t *plan,
+		    hb_font_t *font,
+		    hb_buffer_t *buffer)
+{
+update_consonant_positions (plan, font, buffer);
+insert_dotted_circles (plan, font, buffer);
+hb_glyph_info_t *info = buffer->info;
+unsigned int count = buffer->len;
+if (unlikely (!count)) return;
+unsigned int last = 0;
+unsigned int last_syllable = info[0].syllable();
+for (unsigned int i = 1; i < count; i++)
+if (last_syllable != info[i].syllable()) {
+initial_reordering_syllable (plan, font->face, buffer, last, i);
+last = i;
+last_syllable = info[last].syllable();
+}
+initial_reordering_syllable (plan, font->face, buffer, last, count);
+}
+static void
+final_reordering_syllable (const hb_ot_shape_plan_t *plan,
+			   hb_buffer_t *buffer,
+			   unsigned int start, unsigned int end)
+{
+const indic_shape_plan_t *indic_plan = (const indic_shape_plan_t *) plan->data;
+hb_glyph_info_t *info = buffer->info;
+/* 4. Final reordering:
+*
+* After the localized forms and basic shaping forms GSUB features have been
+* applied (see below), the shaping engine performs some final glyph
+* reordering before applying all the remaining font features to the entire
+* cluster.
+*/
+/* Find base again */
+unsigned int base;
+for (base = start; base < end; base++)
+if (info[base].indic_position() >= POS_BASE_C) {
+if (start < base && info[base].indic_position() > POS_BASE_C)
+base--;
+break;
+}
+if (base == end && start < base &&
+info[base - 1].indic_category() != OT_ZWJ)
+base--;
+while (start < base &&
+	 (info[base].indic_category() == OT_H ||
+	  info[base].indic_category() == OT_N))
+base--;
+/*   o Reorder matras:
+*
+*     If a pre-base matra character had been reordered before applying basic
+*     features, the glyph can be moved closer to the main consonant based on
+*     whether half-forms had been formed. Actual position for the matra is
+*     defined as “after last standalone halant glyph, after initial matra
+*     position and before the main consonant”. If ZWJ or ZWNJ follow this
+*     halant, position is moved after it.
+*/
+if (start + 1 < end && start < base) /* Otherwise there can't be any pre-base matra characters. */
+{
+/* If we lost track of base, alas, position before last thingy. */
+unsigned int new_pos = base == end ? base - 2 : base - 1;
+/* Malayalam / Tamil do not have "half" forms or explicit virama forms.
+* The glyphs formed by 'half' are Chillus or ligated explicit viramas.
+* We want to position matra after them.
+*/
+if (buffer->props.script != HB_SCRIPT_MALAYALAM && buffer->props.script != HB_SCRIPT_TAMIL)
+{
+while (new_pos > start &&
+	     !(is_one_of (info[new_pos], (FLAG (OT_M) | FLAG (OT_H) | FLAG (OT_Coeng)))))
+	new_pos--;
+/* If we found no Halant we are done.
+* Otherwise only proceed if the Halant does
+* not belong to the Matra itself! */
+if (is_halant_or_coeng (info[new_pos]) &&
+	  info[new_pos].indic_position() != POS_PRE_M)
+{
+	/* -> If ZWJ or ZWNJ follow this halant, position is moved after it. */
+	if (new_pos + 1 < end && is_joiner (info[new_pos + 1]))
+	  new_pos++;
+}
+else
+new_pos = start; /* No move. */
+}
+if (start < new_pos && info[new_pos].indic_position () != POS_PRE_M)
+{
+/* Now go see if there's actually any matras... */
+for (unsigned int i = new_pos; i > start; i--)
+	if (info[i - 1].indic_position () == POS_PRE_M)
+	{
+	  unsigned int old_pos = i - 1;
+	  hb_glyph_info_t tmp = info[old_pos];
+	  memmove (&info[old_pos], &info[old_pos + 1], (new_pos - old_pos) * sizeof (info[0]));
+	  info[new_pos] = tmp;
+	  if (old_pos < base && base <= new_pos) /* Shouldn't actually happen. */
+	    base--;
+	  buffer->merge_clusters (new_pos, MIN (end, base + 1));
+	  new_pos--;
+	}
+} else {
+for (unsigned int i = start; i < base; i++)
+	if (info[i].indic_position () == POS_PRE_M) {
+	  buffer->merge_clusters (i, MIN (end, base + 1));
+	  break;
+	}
+}
+}
+/*   o Reorder reph:
+*
+*     Reph’s original position is always at the beginning of the syllable,
+*     (i.e. it is not reordered at the character reordering stage). However,
+*     it will be reordered according to the basic-forms shaping results.
+*     Possible positions for reph, depending on the script, are; after main,
+*     before post-base consonant forms, and after post-base consonant forms.
+*/
+/* Two cases:
+*
+* - If repha is encoded as a sequence of characters (Ra,H or Ra,H,ZWJ), then
+*   we should only move it if the sequence ligated to the repha form.
+*
+* - If repha is encoded separately and in the logical position, we should only
+*   move it if it did NOT ligate.  If it ligated, it's probably the font trying
+*   to make it work without the reordering.
+*/
+if (start + 1 < end &&
+info[start].indic_position() == POS_RA_TO_BECOME_REPH &&
+((info[start].indic_category() == OT_Repha) ^
+_hb_glyph_info_ligated (&info[start])))
+{
+unsigned int new_reph_pos;
+reph_position_t reph_pos = indic_plan->config->reph_pos;
+assert (reph_pos != REPH_POS_DONT_CARE);
+/*       1. If reph should be positioned after post-base consonant forms,
+*          proceed to step 5.
+*/
+if (reph_pos == REPH_POS_AFTER_POST)
+{
+goto reph_step_5;
+}
+/*       2. If the reph repositioning class is not after post-base: target
+*          position is after the first explicit halant glyph between the
+*          first post-reph consonant and last main consonant. If ZWJ or ZWNJ
+*          are following this halant, position is moved after it. If such
+*          position is found, this is the target position. Otherwise,
+*          proceed to the next step.
+*
+*          Note: in old-implementation fonts, where classifications were
+*          fixed in shaping engine, there was no case where reph position
+*          will be found on this step.
+*/
+{
+new_reph_pos = start + 1;
+while (new_reph_pos < base && !is_halant_or_coeng (info[new_reph_pos]))
+	new_reph_pos++;
+if (new_reph_pos < base && is_halant_or_coeng (info[new_reph_pos]))
+{
+	/* ->If ZWJ or ZWNJ are following this halant, position is moved after it. */
+	if (new_reph_pos + 1 < base && is_joiner (info[new_reph_pos + 1]))
+	  new_reph_pos++;
+	goto reph_move;
+}
+}
+/*       3. If reph should be repositioned after the main consonant: find the
+*          first consonant not ligated with main, or find the first
+*          consonant that is not a potential pre-base reordering Ra.
+*/
+if (reph_pos == REPH_POS_AFTER_MAIN)
+{
+new_reph_pos = base;
+while (new_reph_pos + 1 < end && info[new_reph_pos + 1].indic_position() <= POS_AFTER_MAIN)
+	new_reph_pos++;
+if (new_reph_pos < end)
+goto reph_move;
+}
+/*       4. If reph should be positioned before post-base consonant, find
+*          first post-base classified consonant not ligated with main. If no
+*          consonant is found, the target position should be before the
+*          first matra, syllable modifier sign or vedic sign.
+*/
+/* This is our take on what step 4 is trying to say (and failing, BADLY). */
+if (reph_pos == REPH_POS_AFTER_SUB)
+{
+new_reph_pos = base;
+while (new_reph_pos < end &&
+	     !( FLAG (info[new_reph_pos + 1].indic_position()) & (FLAG (POS_POST_C) | FLAG (POS_AFTER_POST) | FLAG (POS_SMVD))))
+	new_reph_pos++;
+if (new_reph_pos < end)
+goto reph_move;
+}
+/*       5. If no consonant is found in steps 3 or 4, move reph to a position
+*          immediately before the first post-base matra, syllable modifier
+*          sign or vedic sign that has a reordering class after the intended
+*          reph position. For example, if the reordering position for reph
+*          is post-main, it will skip above-base matras that also have a
+*          post-main position.
+*/
+reph_step_5:
+{
+/* Copied from step 2. */
+new_reph_pos = start + 1;
+while (new_reph_pos < base && !is_halant_or_coeng (info[new_reph_pos]))
+	new_reph_pos++;
+if (new_reph_pos < base && is_halant_or_coeng (info[new_reph_pos]))
+{
+	/* ->If ZWJ or ZWNJ are following this halant, position is moved after it. */
+	if (new_reph_pos + 1 < base && is_joiner (info[new_reph_pos + 1]))
+	  new_reph_pos++;
+	goto reph_move;
+}
+}
+/*       6. Otherwise, reorder reph to the end of the syllable.
+*/
+{
+new_reph_pos = end - 1;
+while (new_reph_pos > start && info[new_reph_pos].indic_position() == POS_SMVD)
+	new_reph_pos--;
+/*
+* If the Reph is to be ending up after a Matra,Halant sequence,
+* position it before that Halant so it can interact with the Matra.
+* However, if it's a plain Consonant,Halant we shouldn't do that.
+* Uniscribe doesn't do this.
+* TEST: U+0930,U+094D,U+0915,U+094B,U+094D
+*/
+if (!hb_options ().uniscribe_bug_compatible &&
+	  unlikely (is_halant_or_coeng (info[new_reph_pos]))) {
+	for (unsigned int i = base + 1; i < new_reph_pos; i++)
+	  if (info[i].indic_category() == OT_M) {
+	    /* Ok, got it. */
+	    new_reph_pos--;
+	  }
+}
+goto reph_move;
+}
+reph_move:
+{
+buffer->merge_clusters (start, new_reph_pos + 1);
+/* Move */
+hb_glyph_info_t reph = info[start];
+memmove (&info[start], &info[start + 1], (new_reph_pos - start) * sizeof (info[0]));
+info[new_reph_pos] = reph;
+if (start < base && base <= new_reph_pos)
+	base--;
+}
+}
+/*   o Reorder pre-base reordering consonants:
+*
+*     If a pre-base reordering consonant is found, reorder it according to
+*     the following rules:
+*/
+if (indic_plan->mask_array[PREF] && base + 1 < end) /* Otherwise there can't be any pre-base reordering Ra. */
+{
+unsigned int pref_len = indic_plan->config->pref_len;
+for (unsigned int i = base + 1; i < end; i++)
+if ((info[i].mask & indic_plan->mask_array[PREF]) != 0)
+{
+	/*       1. Only reorder a glyph produced by substitution during application
+	 *          of the <pref> feature. (Note that a font may shape a Ra consonant with
+	 *          the feature generally but block it in certain contexts.)
+	 */
+/* Note: We just check that something got substituted.  We don't check that
+	 * the <pref> feature actually did it...
+	 *
+	 * If pref len is longer than one, then only reorder if it ligated.  If
+	 * pref len is one, only reorder if it didn't ligate with other things. */
+	if (_hb_glyph_info_substituted (&info[i]) &&
+	    ((pref_len == 1) ^ _hb_glyph_info_ligated (&info[i])))
+	{
+	  /*
+	   *       2. Try to find a target position the same way as for pre-base matra.
+	   *          If it is found, reorder pre-base consonant glyph.
+	   *
+	   *       3. If position is not found, reorder immediately before main
+	   *          consonant.
+	   */
+	  unsigned int new_pos = base;
+	  /* Malayalam / Tamil do not have "half" forms or explicit virama forms.
+	   * The glyphs formed by 'half' are Chillus or ligated explicit viramas.
+	   * We want to position matra after them.
+	   */
+	  if (buffer->props.script != HB_SCRIPT_MALAYALAM && buffer->props.script != HB_SCRIPT_TAMIL)
+	  {
+	    while (new_pos > start &&
+		   !(is_one_of (info[new_pos - 1], FLAG(OT_M) | HALANT_OR_COENG_FLAGS)))
+	      new_pos--;
+	    /* In Khmer coeng model, a H,Ra can go *after* matras.  If it goes after a
+	     * split matra, it should be reordered to *before* the left part of such matra. */
+	    if (new_pos > start && info[new_pos - 1].indic_category() == OT_M)
+	    {
+	      unsigned int old_pos = i;
+	      for (unsigned int i = base + 1; i < old_pos; i++)
+		if (info[i].indic_category() == OT_M)
+		{
+		  new_pos--;
+		  break;
+		}
+	    }
+	  }
+	  if (new_pos > start && is_halant_or_coeng (info[new_pos - 1]))
+	  {
+	    /* -> If ZWJ or ZWNJ follow this halant, position is moved after it. */
+	    if (new_pos < end && is_joiner (info[new_pos]))
+	      new_pos++;
+	  }
+	  {
+	    unsigned int old_pos = i;
+	    buffer->merge_clusters (new_pos, old_pos + 1);
+	    hb_glyph_info_t tmp = info[old_pos];
+	    memmove (&info[new_pos + 1], &info[new_pos], (old_pos - new_pos) * sizeof (info[0]));
+	    info[new_pos] = tmp;
+	    if (new_pos <= base && base < old_pos)
+	      base++;
+	  }
+	}
+break;
+}
+}
+/* Apply 'init' to the Left Matra if it's a word start. */
+if (info[start].indic_position () == POS_PRE_M &&
+(!start ||
+!(FLAG (_hb_glyph_info_get_general_category (&info[start - 1])) &
+	 FLAG_RANGE (HB_UNICODE_GENERAL_CATEGORY_FORMAT, HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK))))
+info[start].mask |= indic_plan->mask_array[INIT];
+/*
+* Finish off the clusters and go home!
+*/
+if (hb_options ().uniscribe_bug_compatible)
+{
+switch ((hb_tag_t) plan->props.script)
+{
+case HB_SCRIPT_TAMIL:
+case HB_SCRIPT_SINHALA:
+break;
+default:
+	/* Uniscribe merges the entire cluster... Except for Tamil & Sinhala.
+	 * This means, half forms are submerged into the main consonants cluster.
+	 * This is unnecessary, and makes cursor positioning harder, but that's what
+	 * Uniscribe does. */
+	buffer->merge_clusters (start, end);
+	break;
+}
+}
+}
+static void
+final_reordering (const hb_ot_shape_plan_t *plan,
+		  hb_font_t *font HB_UNUSED,
+		  hb_buffer_t *buffer)
+{
+unsigned int count = buffer->len;
+if (unlikely (!count)) return;
+hb_glyph_info_t *info = buffer->info;
+unsigned int last = 0;
+unsigned int last_syllable = info[0].syllable();
+for (unsigned int i = 1; i < count; i++)
+if (last_syllable != info[i].syllable()) {
+final_reordering_syllable (plan, buffer, last, i);
+last = i;
+last_syllable = info[last].syllable();
+}
+final_reordering_syllable (plan, buffer, last, count);
+HB_BUFFER_DEALLOCATE_VAR (buffer, indic_category);
+HB_BUFFER_DEALLOCATE_VAR (buffer, indic_position);
+}
+static void
+clear_syllables (const hb_ot_shape_plan_t *plan HB_UNUSED,
+		 hb_font_t *font HB_UNUSED,
+		 hb_buffer_t *buffer)
+{
+hb_glyph_info_t *info = buffer->info;
+unsigned int count = buffer->len;
+for (unsigned int i = 0; i < count; i++)
+info[i].syllable() = 0;
+}
+static bool
+decompose_indic (const hb_ot_shape_normalize_context_t *c,
+		 hb_codepoint_t  ab,
+		 hb_codepoint_t *a,
+		 hb_codepoint_t *b)
+{
+switch (ab)
+{
+/* Don't decompose these. */
+case 0x0931  : return false;
+case 0x0B94  : return false;
+/*
+* Decompose split matras that don't have Unicode decompositions.
+*/
+case 0x0F77  : *a = 0x0FB2; *b= 0x0F81; return true;
+case 0x0F79  : *a = 0x0FB3; *b= 0x0F81; return true;
+case 0x17BE  : *a = 0x17C1; *b= 0x17BE; return true;
+case 0x17BF  : *a = 0x17C1; *b= 0x17BF; return true;
+case 0x17C0  : *a = 0x17C1; *b= 0x17C0; return true;
+case 0x17C4  : *a = 0x17C1; *b= 0x17C4; return true;
+case 0x17C5  : *a = 0x17C1; *b= 0x17C5; return true;
+case 0x1925  : *a = 0x1920; *b= 0x1923; return true;
+case 0x1926  : *a = 0x1920; *b= 0x1924; return true;
+case 0x1B3C  : *a = 0x1B42; *b= 0x1B3C; return true;
+case 0x1112E  : *a = 0x11127; *b= 0x11131; return true;
+case 0x1112F  : *a = 0x11127; *b= 0x11132; return true;
+#if 0
+/* This one has no decomposition in Unicode, but needs no decomposition either. */
+/* case 0x0AC9  : return false; */
+case 0x0B57  : *a = no decomp, -> RIGHT; return true;
+case 0x1C29  : *a = no decomp, -> LEFT; return true;
+case 0xA9C0  : *a = no decomp, -> RIGHT; return true;
+case 0x111BF  : *a = no decomp, -> ABOVE; return true;
+#endif
+}
+if ((ab == 0x0DDA || hb_in_range<hb_codepoint_t> (ab, 0x0DDC, 0x0DDE)))
+{
+/*
+* Sinhala split matras...  Let the fun begin.
+*
+* These four characters have Unicode decompositions.  However, Uniscribe
+* decomposes them "Khmer-style", that is, it uses the character itself to
+* get the second half.  The first half of all four decompositions is always
+* U+0DD9.
+*
+* Now, there are buggy fonts, namely, the widely used lklug.ttf, that are
+* broken with Uniscribe.  But we need to support them.  As such, we only
+* do the Uniscribe-style decomposition if the character is transformed into
+* its "sec.half" form by the 'pstf' feature.  Otherwise, we fall back to
+* Unicode decomposition.
+*
+* Note that we can't unconditionally use Unicode decomposition.  That would
+* break some other fonts, that are designed to work with Uniscribe, and
+* don't have positioning features for the Unicode-style decomposition.
+*
+* Argh...
+*
+* The Uniscribe behavior is now documented in the newly published Sinhala
+* spec in 2012:
+*
+*   http://www.microsoft.com/typography/OpenTypeDev/sinhala/intro.htm#shaping
+*/
+const indic_shape_plan_t *indic_plan = (const indic_shape_plan_t *) c->plan->data;
+hb_codepoint_t glyph;
+if (hb_options ().uniscribe_bug_compatible ||
+	(c->font->get_glyph (ab, 0, &glyph) &&
+	 indic_plan->pstf.would_substitute (&glyph, 1, c->font->face)))
+{
+/* Ok, safe to use Uniscribe-style decomposition. */
+*a = 0x0DD9;
+*b = ab;
+return true;
+}
+}
+return c->unicode->decompose (ab, a, b);
+}
+static bool
+compose_indic (const hb_ot_shape_normalize_context_t *c,
+	       hb_codepoint_t  a,
+	       hb_codepoint_t  b,
+	       hb_codepoint_t *ab)
+{
+/* Avoid recomposing split matras. */
+if (HB_UNICODE_GENERAL_CATEGORY_IS_MARK (c->unicode->general_category (a)))
+return false;
+/* Composition-exclusion exceptions that we want to recompose. */
+if (a == 0x09AF && b == 0x09BC) { *ab = 0x09DF; return true; }
+return c->unicode->compose (a, b, ab);
+}
+const hb_ot_complex_shaper_t _hb_ot_complex_shaper_indic =
+{
+"indic",
+collect_features_indic,
+override_features_indic,
+data_create_indic,
+data_destroy_indic,
+NULL, /* preprocess_text */
+HB_OT_SHAPE_NORMALIZATION_MODE_COMPOSED_DIACRITICS_NO_SHORT_CIRCUIT,
+decompose_indic,
+compose_indic,
+setup_masks_indic,
+HB_OT_SHAPE_ZERO_WIDTH_MARKS_NONE,
+false, /* fallback_position */
+};

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comparison: gfx/harfbuzz/src/hb-ot-shape-complex-indic.cc

gfx/harfbuzz/src/hb-ot-shape-complex-indic.cc