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+/*
+ * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
+ *
+ * This is part of HarfBuzz, an OpenType Layout engine 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.
+ */
+
+#include "harfbuzz-shaper.h"
+#include "harfbuzz-shaper-private.h"
+
+#include <assert.h>
+#include <stdio.h>
+
+/*
+// Vocabulary
+// Base -> A consonant or an independent vowel in its full (not subscript) form. It is the
+// center of the syllable, it can be surrounded by coeng (subscript) consonants, vowels,
+// split vowels, signs... but there is only one base in a syllable, it has to be coded as
+// the first character of the syllable.
+// split vowel --> vowel that has two parts placed separately (e.g. Before and after the consonant).
+// Khmer language has five of them. Khmer split vowels either have one part before the
+// base and one after the base or they have a part before the base and a part above the base.
+// The first part of all Khmer split vowels is the same character, identical to
+// the glyph of Khmer dependent vowel SRA EI
+// coeng --> modifier used in Khmer to construct coeng (subscript) consonants
+// Differently than indian languages, the coeng modifies the consonant that follows it,
+// not the one preceding it Each consonant has two forms, the base form and the subscript form
+// the base form is the normal one (using the consonants code-point), the subscript form is
+// displayed when the combination coeng + consonant is encountered.
+// Consonant of type 1 -> A consonant which has subscript for that only occupies space under a base consonant
+// Consonant of type 2.-> Its subscript form occupies space under and before the base (only one, RO)
+// Consonant of Type 3 -> Its subscript form occupies space under and after the base (KHO, CHHO, THHO, BA, YO, SA)
+// Consonant shifter -> Khmer has to series of consonants. The same dependent vowel has different sounds
+// if it is attached to a consonant of the first series or a consonant of the second series
+// Most consonants have an equivalent in the other series, but some of theme exist only in
+// one series (for example SA). If we want to use the consonant SA with a vowel sound that
+// can only be done with a vowel sound that corresponds to a vowel accompanying a consonant
+// of the other series, then we need to use a consonant shifter: TRIISAP or MUSIKATOAN
+// x17C9 y x17CA. TRIISAP changes a first series consonant to second series sound and
+// MUSIKATOAN a second series consonant to have a first series vowel sound.
+// Consonant shifter are both normally supercript marks, but, when they are followed by a
+// superscript, they change shape and take the form of subscript dependent vowel SRA U.
+// If they are in the same syllable as a coeng consonant, Unicode 3.0 says that they
+// should be typed before the coeng. Unicode 4.0 breaks the standard and says that it should
+// be placed after the coeng consonant.
+// Dependent vowel -> In khmer dependent vowels can be placed above, below, before or after the base
+// Each vowel has its own position. Only one vowel per syllable is allowed.
+// Signs -> Khmer has above signs and post signs. Only one above sign and/or one post sign are
+// Allowed in a syllable.
+//
+//
+// order is important here! This order must be the same that is found in each horizontal
+// line in the statetable for Khmer (see khmerStateTable) .
+*/
+enum KhmerCharClassValues {
+ CC_RESERVED = 0,
+ CC_CONSONANT = 1, /* Consonant of type 1 or independent vowel */
+ CC_CONSONANT2 = 2, /* Consonant of type 2 */
+ CC_CONSONANT3 = 3, /* Consonant of type 3 */
+ CC_ZERO_WIDTH_NJ_MARK = 4, /* Zero Width non joiner character (0x200C) */
+ CC_CONSONANT_SHIFTER = 5,
+ CC_ROBAT = 6, /* Khmer special diacritic accent -treated differently in state table */
+ CC_COENG = 7, /* Subscript consonant combining character */
+ CC_DEPENDENT_VOWEL = 8,
+ CC_SIGN_ABOVE = 9,
+ CC_SIGN_AFTER = 10,
+ CC_ZERO_WIDTH_J_MARK = 11, /* Zero width joiner character */
+ CC_COUNT = 12 /* This is the number of character classes */
+};
+
+
+enum KhmerCharClassFlags {
+ CF_CLASS_MASK = 0x0000FFFF,
+
+ CF_CONSONANT = 0x01000000, /* flag to speed up comparing */
+ CF_SPLIT_VOWEL = 0x02000000, /* flag for a split vowel -> the first part is added in front of the syllable */
+ CF_DOTTED_CIRCLE = 0x04000000, /* add a dotted circle if a character with this flag is the first in a syllable */
+ CF_COENG = 0x08000000, /* flag to speed up comparing */
+ CF_SHIFTER = 0x10000000, /* flag to speed up comparing */
+ CF_ABOVE_VOWEL = 0x20000000, /* flag to speed up comparing */
+
+ /* position flags */
+ CF_POS_BEFORE = 0x00080000,
+ CF_POS_BELOW = 0x00040000,
+ CF_POS_ABOVE = 0x00020000,
+ CF_POS_AFTER = 0x00010000,
+ CF_POS_MASK = 0x000f0000
+};
+
+
+/* Characters that get referred to by name */
+enum KhmerChar {
+ C_SIGN_ZWNJ = 0x200C,
+ C_SIGN_ZWJ = 0x200D,
+ C_RO = 0x179A,
+ C_VOWEL_AA = 0x17B6,
+ C_SIGN_NIKAHIT = 0x17C6,
+ C_VOWEL_E = 0x17C1,
+ C_COENG = 0x17D2
+};
+
+
+/*
+// simple classes, they are used in the statetable (in this file) to control the length of a syllable
+// they are also used to know where a character should be placed (location in reference to the base character)
+// and also to know if a character, when independently displayed, should be displayed with a dotted-circle to
+// indicate error in syllable construction
+*/
+enum {
+ _xx = CC_RESERVED,
+ _sa = CC_SIGN_ABOVE | CF_DOTTED_CIRCLE | CF_POS_ABOVE,
+ _sp = CC_SIGN_AFTER | CF_DOTTED_CIRCLE| CF_POS_AFTER,
+ _c1 = CC_CONSONANT | CF_CONSONANT,
+ _c2 = CC_CONSONANT2 | CF_CONSONANT,
+ _c3 = CC_CONSONANT3 | CF_CONSONANT,
+ _rb = CC_ROBAT | CF_POS_ABOVE | CF_DOTTED_CIRCLE,
+ _cs = CC_CONSONANT_SHIFTER | CF_DOTTED_CIRCLE | CF_SHIFTER,
+ _dl = CC_DEPENDENT_VOWEL | CF_POS_BEFORE | CF_DOTTED_CIRCLE,
+ _db = CC_DEPENDENT_VOWEL | CF_POS_BELOW | CF_DOTTED_CIRCLE,
+ _da = CC_DEPENDENT_VOWEL | CF_POS_ABOVE | CF_DOTTED_CIRCLE | CF_ABOVE_VOWEL,
+ _dr = CC_DEPENDENT_VOWEL | CF_POS_AFTER | CF_DOTTED_CIRCLE,
+ _co = CC_COENG | CF_COENG | CF_DOTTED_CIRCLE,
+
+ /* split vowel */
+ _va = _da | CF_SPLIT_VOWEL,
+ _vr = _dr | CF_SPLIT_VOWEL
+};
+
+
+/*
+// Character class: a character class value
+// ORed with character class flags.
+*/
+typedef unsigned long KhmerCharClass;
+
+
+/*
+// Character class tables
+// _xx character does not combine into syllable, such as numbers, puntuation marks, non-Khmer signs...
+// _sa Sign placed above the base
+// _sp Sign placed after the base
+// _c1 Consonant of type 1 or independent vowel (independent vowels behave as type 1 consonants)
+// _c2 Consonant of type 2 (only RO)
+// _c3 Consonant of type 3
+// _rb Khmer sign robat u17CC. combining mark for subscript consonants
+// _cd Consonant-shifter
+// _dl Dependent vowel placed before the base (left of the base)
+// _db Dependent vowel placed below the base
+// _da Dependent vowel placed above the base
+// _dr Dependent vowel placed behind the base (right of the base)
+// _co Khmer combining mark COENG u17D2, combines with the consonant or independent vowel following
+// it to create a subscript consonant or independent vowel
+// _va Khmer split vowel in which the first part is before the base and the second one above the base
+// _vr Khmer split vowel in which the first part is before the base and the second one behind (right of) the base
+*/
+static const KhmerCharClass khmerCharClasses[] = {
+ _c1, _c1, _c1, _c3, _c1, _c1, _c1, _c1, _c3, _c1, _c1, _c1, _c1, _c3, _c1, _c1, /* 1780 - 178F */
+ _c1, _c1, _c1, _c1, _c3, _c1, _c1, _c1, _c1, _c3, _c2, _c1, _c1, _c1, _c3, _c3, /* 1790 - 179F */
+ _c1, _c3, _c1, _c1, _c1, _c1, _c1, _c1, _c1, _c1, _c1, _c1, _c1, _c1, _c1, _c1, /* 17A0 - 17AF */
+ _c1, _c1, _c1, _c1, _dr, _dr, _dr, _da, _da, _da, _da, _db, _db, _db, _va, _vr, /* 17B0 - 17BF */
+ _vr, _dl, _dl, _dl, _vr, _vr, _sa, _sp, _sp, _cs, _cs, _sa, _rb, _sa, _sa, _sa, /* 17C0 - 17CF */
+ _sa, _sa, _co, _sa, _xx, _xx, _xx, _xx, _xx, _xx, _xx, _xx, _xx, _sa, _xx, _xx /* 17D0 - 17DF */
+};
+
+/* this enum must reflect the range of khmerCharClasses */
+enum KhmerCharClassesRange {
+ KhmerFirstChar = 0x1780,
+ KhmerLastChar = 0x17df
+};
+
+/*
+// Below we define how a character in the input string is either in the khmerCharClasses table
+// (in which case we get its type back), a ZWJ or ZWNJ (two characters that may appear
+// within the syllable, but are not in the table) we also get their type back, or an unknown object
+// in which case we get _xx (CC_RESERVED) back
+*/
+static KhmerCharClass getKhmerCharClass(HB_UChar16 uc)
+{
+ if (uc == C_SIGN_ZWJ) {
+ return CC_ZERO_WIDTH_J_MARK;
+ }
+
+ if (uc == C_SIGN_ZWNJ) {
+ return CC_ZERO_WIDTH_NJ_MARK;
+ }
+
+ if (uc < KhmerFirstChar || uc > KhmerLastChar) {
+ return CC_RESERVED;
+ }
+
+ return khmerCharClasses[uc - KhmerFirstChar];
+}
+
+
+/*
+// The stateTable is used to calculate the end (the length) of a well
+// formed Khmer Syllable.
+//
+// Each horizontal line is ordered exactly the same way as the values in KhmerClassTable
+// CharClassValues. This coincidence of values allows the follow up of the table.
+//
+// Each line corresponds to a state, which does not necessarily need to be a type
+// of component... for example, state 2 is a base, with is always a first character
+// in the syllable, but the state could be produced a consonant of any type when
+// it is the first character that is analysed (in ground state).
+//
+// Differentiating 3 types of consonants is necessary in order to
+// forbid the use of certain combinations, such as having a second
+// coeng after a coeng RO,
+// The inexistent possibility of having a type 3 after another type 3 is permitted,
+// eliminating it would very much complicate the table, and it does not create typing
+// problems, as the case above.
+//
+// The table is quite complex, in order to limit the number of coeng consonants
+// to 2 (by means of the table).
+//
+// There a peculiarity, as far as Unicode is concerned:
+// - The consonant-shifter is considered in two possible different
+// locations, the one considered in Unicode 3.0 and the one considered in
+// Unicode 4.0. (there is a backwards compatibility problem in this standard).
+//
+//
+// xx independent character, such as a number, punctuation sign or non-khmer char
+//
+// c1 Khmer consonant of type 1 or an independent vowel
+// that is, a letter in which the subscript for is only under the
+// base, not taking any space to the right or to the left
+//
+// c2 Khmer consonant of type 2, the coeng form takes space under
+// and to the left of the base (only RO is of this type)
+//
+// c3 Khmer consonant of type 3. Its subscript form takes space under
+// and to the right of the base.
+//
+// cs Khmer consonant shifter
+//
+// rb Khmer robat
+//
+// co coeng character (u17D2)
+//
+// dv dependent vowel (including split vowels, they are treated in the same way).
+// even if dv is not defined above, the component that is really tested for is
+// KhmerClassTable::CC_DEPENDENT_VOWEL, which is common to all dependent vowels
+//
+// zwj Zero Width joiner
+//
+// zwnj Zero width non joiner
+//
+// sa above sign
+//
+// sp post sign
+//
+// there are lines with equal content but for an easier understanding
+// (and maybe change in the future) we did not join them
+*/
+static const signed char khmerStateTable[][CC_COUNT] =
+{
+ /* xx c1 c2 c3 zwnj cs rb co dv sa sp zwj */
+ { 1, 2, 2, 2, 1, 1, 1, 6, 1, 1, 1, 2}, /* 0 - ground state */
+ {-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1}, /* 1 - exit state (or sign to the right of the syllable) */
+ {-1, -1, -1, -1, 3, 4, 5, 6, 16, 17, 1, -1}, /* 2 - Base consonant */
+ {-1, -1, -1, -1, -1, 4, -1, -1, 16, -1, -1, -1}, /* 3 - First ZWNJ before a register shifter It can only be followed by a shifter or a vowel */
+ {-1, -1, -1, -1, 15, -1, -1, 6, 16, 17, 1, 14}, /* 4 - First register shifter */
+ {-1, -1, -1, -1, -1, -1, -1, -1, 20, -1, 1, -1}, /* 5 - Robat */
+ {-1, 7, 8, 9, -1, -1, -1, -1, -1, -1, -1, -1}, /* 6 - First Coeng */
+ {-1, -1, -1, -1, 12, 13, -1, 10, 16, 17, 1, 14}, /* 7 - First consonant of type 1 after coeng */
+ {-1, -1, -1, -1, 12, 13, -1, -1, 16, 17, 1, 14}, /* 8 - First consonant of type 2 after coeng */
+ {-1, -1, -1, -1, 12, 13, -1, 10, 16, 17, 1, 14}, /* 9 - First consonant or type 3 after ceong */
+ {-1, 11, 11, 11, -1, -1, -1, -1, -1, -1, -1, -1}, /* 10 - Second Coeng (no register shifter before) */
+ {-1, -1, -1, -1, 15, -1, -1, -1, 16, 17, 1, 14}, /* 11 - Second coeng consonant (or ind. vowel) no register shifter before */
+ {-1, -1, -1, -1, -1, 13, -1, -1, 16, -1, -1, -1}, /* 12 - Second ZWNJ before a register shifter */
+ {-1, -1, -1, -1, 15, -1, -1, -1, 16, 17, 1, 14}, /* 13 - Second register shifter */
+ {-1, -1, -1, -1, -1, -1, -1, -1, 16, -1, -1, -1}, /* 14 - ZWJ before vowel */
+ {-1, -1, -1, -1, -1, -1, -1, -1, 16, -1, -1, -1}, /* 15 - ZWNJ before vowel */
+ {-1, -1, -1, -1, -1, -1, -1, -1, -1, 17, 1, 18}, /* 16 - dependent vowel */
+ {-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 1, 18}, /* 17 - sign above */
+ {-1, -1, -1, -1, -1, -1, -1, 19, -1, -1, -1, -1}, /* 18 - ZWJ after vowel */
+ {-1, 1, -1, 1, -1, -1, -1, -1, -1, -1, -1, -1}, /* 19 - Third coeng */
+ {-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 1, -1}, /* 20 - dependent vowel after a Robat */
+};
+
+
+/* #define KHMER_DEBUG */
+#ifdef KHMER_DEBUG
+#define KHDEBUG qDebug
+#else
+#define KHDEBUG if(0) printf
+#endif
+
+/*
+// Given an input string of characters and a location in which to start looking
+// calculate, using the state table, which one is the last character of the syllable
+// that starts in the starting position.
+*/
+static int khmer_nextSyllableBoundary(const HB_UChar16 *s, int start, int end, HB_Bool *invalid)
+{
+ const HB_UChar16 *uc = s + start;
+ int state = 0;
+ int pos = start;
+ *invalid = FALSE;
+
+ while (pos < end) {
+ KhmerCharClass charClass = getKhmerCharClass(*uc);
+ if (pos == start) {
+ *invalid = (charClass > 0) && ! (charClass & CF_CONSONANT);
+ }
+ state = khmerStateTable[state][charClass & CF_CLASS_MASK];
+
+ KHDEBUG("state[%d]=%d class=%8lx (uc=%4x)", pos - start, state,
+ charClass, *uc );
+
+ if (state < 0) {
+ break;
+ }
+ ++uc;
+ ++pos;
+ }
+ return pos;
+}
+
+#ifndef NO_OPENTYPE
+static const HB_OpenTypeFeature khmer_features[] = {
+ { HB_MAKE_TAG( 'p', 'r', 'e', 'f' ), PreFormProperty },
+ { HB_MAKE_TAG( 'b', 'l', 'w', 'f' ), BelowFormProperty },
+ { HB_MAKE_TAG( 'a', 'b', 'v', 'f' ), AboveFormProperty },
+ { HB_MAKE_TAG( 'p', 's', 't', 'f' ), PostFormProperty },
+ { HB_MAKE_TAG( 'p', 'r', 'e', 's' ), PreSubstProperty },
+ { HB_MAKE_TAG( 'b', 'l', 'w', 's' ), BelowSubstProperty },
+ { HB_MAKE_TAG( 'a', 'b', 'v', 's' ), AboveSubstProperty },
+ { HB_MAKE_TAG( 'p', 's', 't', 's' ), PostSubstProperty },
+ { HB_MAKE_TAG( 'c', 'l', 'i', 'g' ), CligProperty },
+ { 0, 0 }
+};
+#endif
+
+
+static HB_Bool khmer_shape_syllable(HB_Bool openType, HB_ShaperItem *item)
+{
+/* KHDEBUG("syllable from %d len %d, str='%s'", item->from, item->length,
+ item->string->mid(item->from, item->length).toUtf8().data()); */
+
+ int len = 0;
+ int syllableEnd = item->item.pos + item->item.length;
+ unsigned short reordered[16];
+ unsigned char properties[16];
+ enum {
+ AboveForm = 0x01,
+ PreForm = 0x02,
+ PostForm = 0x04,
+ BelowForm = 0x08
+ };
+#ifndef NO_OPENTYPE
+ const int availableGlyphs = item->num_glyphs;
+#endif
+ int coengRo;
+ int i;
+
+ /* according to the specs this is the max length one can get
+ ### the real value should be smaller */
+ assert(item->item.length < 13);
+
+ memset(properties, 0, 16*sizeof(unsigned char));
+
+#ifdef KHMER_DEBUG
+ qDebug("original:");
+ for (int i = from; i < syllableEnd; i++) {
+ qDebug(" %d: %4x", i, string[i]);
+ }
+#endif
+
+ /*
+ // write a pre vowel or the pre part of a split vowel first
+ // and look out for coeng + ro. RO is the only vowel of type 2, and
+ // therefore the only one that requires saving space before the base.
+ */
+ coengRo = -1; /* There is no Coeng Ro, if found this value will change */
+ for (i = item->item.pos; i < syllableEnd; i += 1) {
+ KhmerCharClass charClass = getKhmerCharClass(item->string[i]);
+
+ /* if a split vowel, write the pre part. In Khmer the pre part
+ is the same for all split vowels, same glyph as pre vowel C_VOWEL_E */
+ if (charClass & CF_SPLIT_VOWEL) {
+ reordered[len] = C_VOWEL_E;
+ properties[len] = PreForm;
+ ++len;
+ break; /* there can be only one vowel */
+ }
+ /* if a vowel with pos before write it out */
+ if (charClass & CF_POS_BEFORE) {
+ reordered[len] = item->string[i];
+ properties[len] = PreForm;
+ ++len;
+ break; /* there can be only one vowel */
+ }
+ /* look for coeng + ro and remember position
+ works because coeng + ro is always in front of a vowel (if there is a vowel)
+ and because CC_CONSONANT2 is enough to identify it, as it is the only consonant
+ with this flag */
+ if ( (charClass & CF_COENG) && (i + 1 < syllableEnd) &&
+ ( (getKhmerCharClass(item->string[i+1]) & CF_CLASS_MASK) == CC_CONSONANT2) ) {
+ coengRo = i;
+ }
+ }
+
+ /* write coeng + ro if found */
+ if (coengRo > -1) {
+ reordered[len] = C_COENG;
+ properties[len] = PreForm;
+ ++len;
+ reordered[len] = C_RO;
+ properties[len] = PreForm;
+ ++len;
+ }
+
+ /*
+ shall we add a dotted circle?
+ If in the position in which the base should be (first char in the string) there is
+ a character that has the Dotted circle flag (a character that cannot be a base)
+ then write a dotted circle */
+ if (getKhmerCharClass(item->string[item->item.pos]) & CF_DOTTED_CIRCLE) {
+ reordered[len] = C_DOTTED_CIRCLE;
+ ++len;
+ }
+
+ /* copy what is left to the output, skipping before vowels and
+ coeng Ro if they are present */
+ for (i = item->item.pos; i < syllableEnd; i += 1) {
+ HB_UChar16 uc = item->string[i];
+ KhmerCharClass charClass = getKhmerCharClass(uc);
+
+ /* skip a before vowel, it was already processed */
+ if (charClass & CF_POS_BEFORE) {
+ continue;
+ }
+
+ /* skip coeng + ro, it was already processed */
+ if (i == coengRo) {
+ i += 1;
+ continue;
+ }
+
+ switch (charClass & CF_POS_MASK)
+ {
+ case CF_POS_ABOVE :
+ reordered[len] = uc;
+ properties[len] = AboveForm;
+ ++len;
+ break;
+
+ case CF_POS_AFTER :
+ reordered[len] = uc;
+ properties[len] = PostForm;
+ ++len;
+ break;
+
+ case CF_POS_BELOW :
+ reordered[len] = uc;
+ properties[len] = BelowForm;
+ ++len;
+ break;
+
+ default:
+ /* assign the correct flags to a coeng consonant
+ Consonants of type 3 are taged as Post forms and those type 1 as below forms */
+ if ( (charClass & CF_COENG) && i + 1 < syllableEnd ) {
+ unsigned char property = (getKhmerCharClass(item->string[i+1]) & CF_CLASS_MASK) == CC_CONSONANT3 ?
+ PostForm : BelowForm;
+ reordered[len] = uc;
+ properties[len] = property;
+ ++len;
+ i += 1;
+ reordered[len] = item->string[i];
+ properties[len] = property;
+ ++len;
+ break;
+ }
+
+ /* if a shifter is followed by an above vowel change the shifter to below form,
+ an above vowel can have two possible positions i + 1 or i + 3
+ (position i+1 corresponds to unicode 3, position i+3 to Unicode 4)
+ and there is an extra rule for C_VOWEL_AA + C_SIGN_NIKAHIT also for two
+ different positions, right after the shifter or after a vowel (Unicode 4) */
+ if ( (charClass & CF_SHIFTER) && (i + 1 < syllableEnd) ) {
+ if (getKhmerCharClass(item->string[i+1]) & CF_ABOVE_VOWEL ) {
+ reordered[len] = uc;
+ properties[len] = BelowForm;
+ ++len;
+ break;
+ }
+ if (i + 2 < syllableEnd &&
+ (item->string[i+1] == C_VOWEL_AA) &&
+ (item->string[i+2] == C_SIGN_NIKAHIT) )
+ {
+ reordered[len] = uc;
+ properties[len] = BelowForm;
+ ++len;
+ break;
+ }
+ if (i + 3 < syllableEnd && (getKhmerCharClass(item->string[i+3]) & CF_ABOVE_VOWEL) ) {
+ reordered[len] = uc;
+ properties[len] = BelowForm;
+ ++len;
+ break;
+ }
+ if (i + 4 < syllableEnd &&
+ (item->string[i+3] == C_VOWEL_AA) &&
+ (item->string[i+4] == C_SIGN_NIKAHIT) )
+ {
+ reordered[len] = uc;
+ properties[len] = BelowForm;
+ ++len;
+ break;
+ }
+ }
+
+ /* default - any other characters */
+ reordered[len] = uc;
+ ++len;
+ break;
+ } /* switch */
+ } /* for */
+
+ if (!item->font->klass->convertStringToGlyphIndices(item->font,
+ reordered, len,
+ item->glyphs, &item->num_glyphs,
+ item->item.bidiLevel % 2))
+ return FALSE;
+
+
+ KHDEBUG("after shaping: len=%d", len);
+ for (i = 0; i < len; i++) {
+ item->attributes[i].mark = FALSE;
+ item->attributes[i].clusterStart = FALSE;
+ item->attributes[i].justification = 0;
+ item->attributes[i].zeroWidth = FALSE;
+ KHDEBUG(" %d: %4x property=%x", i, reordered[i], properties[i]);
+ }
+
+ /* now we have the syllable in the right order, and can start running it through open type. */
+
+#ifndef NO_OPENTYPE
+ if (openType) {
+ hb_uint32 where[16];
+ for (i = 0; i < len; ++i) {
+ where[i] = ~(PreSubstProperty
+ | BelowSubstProperty
+ | AboveSubstProperty
+ | PostSubstProperty
+ | CligProperty
+ | PositioningProperties);
+ if (properties[i] == PreForm)
+ where[i] &= ~PreFormProperty;
+ else if (properties[i] == BelowForm)
+ where[i] &= ~BelowFormProperty;
+ else if (properties[i] == AboveForm)
+ where[i] &= ~AboveFormProperty;
+ else if (properties[i] == PostForm)
+ where[i] &= ~PostFormProperty;
+ }
+
+ HB_OpenTypeShape(item, where);
+ if (!HB_OpenTypePosition(item, availableGlyphs, /*doLogClusters*/FALSE))
+ return FALSE;
+ } else
+#endif
+ {
+ KHDEBUG("Not using openType");
+ HB_HeuristicPosition(item);
+ }
+
+ item->attributes[0].clusterStart = TRUE;
+ return TRUE;
+}
+
+HB_Bool HB_KhmerShape(HB_ShaperItem *item)
+{
+ HB_Bool openType = FALSE;
+ unsigned short *logClusters = item->log_clusters;
+ int i;
+
+ HB_ShaperItem syllable = *item;
+ int first_glyph = 0;
+
+ int sstart = item->item.pos;
+ int end = sstart + item->item.length;
+
+ assert(item->item.script == HB_Script_Khmer);
+
+#ifndef NO_OPENTYPE
+ openType = HB_SelectScript(item, khmer_features);
+#endif
+
+ KHDEBUG("khmer_shape: from %d length %d", item->item.pos, item->item.length);
+ while (sstart < end) {
+ HB_Bool invalid;
+ int send = khmer_nextSyllableBoundary(item->string, sstart, end, &invalid);
+ KHDEBUG("syllable from %d, length %d, invalid=%s", sstart, send-sstart,
+ invalid ? "TRUE" : "FALSE");
+ syllable.item.pos = sstart;
+ syllable.item.length = send-sstart;
+ syllable.glyphs = item->glyphs + first_glyph;
+ syllable.attributes = item->attributes + first_glyph;
+ syllable.offsets = item->offsets + first_glyph;
+ syllable.advances = item->advances + first_glyph;
+ syllable.num_glyphs = item->num_glyphs - first_glyph;
+ if (!khmer_shape_syllable(openType, &syllable)) {
+ KHDEBUG("syllable shaping failed, syllable requests %d glyphs", syllable.num_glyphs);
+ item->num_glyphs += syllable.num_glyphs;
+ return FALSE;
+ }
+ /* fix logcluster array */
+ KHDEBUG("syllable:");
+ for (i = first_glyph; i < first_glyph + (int)syllable.num_glyphs; ++i)
+ KHDEBUG(" %d -> glyph %x", i, item->glyphs[i]);
+ KHDEBUG(" logclusters:");
+ for (i = sstart; i < send; ++i) {
+ KHDEBUG(" %d -> glyph %d", i, first_glyph);
+ logClusters[i-item->item.pos] = first_glyph;
+ }
+ sstart = send;
+ first_glyph += syllable.num_glyphs;
+ }
+ item->num_glyphs = first_glyph;
+ return TRUE;
+}
+
+void HB_KhmerAttributes(HB_Script script, const HB_UChar16 *text, hb_uint32 from, hb_uint32 len, HB_CharAttributes *attributes)
+{
+ int end = from + len;
+ const HB_UChar16 *uc = text + from;
+ hb_uint32 i = 0;
+ HB_UNUSED(script);
+ attributes += from;
+ while ( i < len ) {
+ HB_Bool invalid;
+ hb_uint32 boundary = khmer_nextSyllableBoundary( text, from+i, end, &invalid ) - from;
+
+ attributes[i].charStop = TRUE;
+
+ if ( boundary > len-1 ) boundary = len;
+ i++;
+ while ( i < boundary ) {
+ attributes[i].charStop = FALSE;
+ ++uc;
+ ++i;
+ }
+ assert( i == boundary );
+ }
+}
+