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/*******************************************************************
*
* Copyright 2007 Trolltech ASA
*
* This is part of HarfBuzz, an OpenType Layout engine library.
*
* See the file name COPYING for licensing information.
*
******************************************************************/
#include "harfbuzz-shaper.h"
#include "harfbuzz-shaper-private.h"
#include <assert.h>
/*
tibetan syllables are of the form:
head position consonant
first sub-joined consonant
....intermediate sub-joined consonants (if any)
last sub-joined consonant
sub-joined vowel (a-chung U+0F71)
standard or compound vowel sign (or 'virama' for devanagari transliteration)
*/
typedef enum {
TibetanOther,
TibetanHeadConsonant,
TibetanSubjoinedConsonant,
TibetanSubjoinedVowel,
TibetanVowel
} TibetanForm;
/* this table starts at U+0f40 */
static const unsigned char tibetanForm[0x80] = {
TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant,
TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant,
TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant,
TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant,
TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant,
TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant,
TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant,
TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant,
TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant,
TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant,
TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant, TibetanHeadConsonant,
TibetanOther, TibetanOther, TibetanOther, TibetanOther,
TibetanOther, TibetanVowel, TibetanVowel, TibetanVowel,
TibetanVowel, TibetanVowel, TibetanVowel, TibetanVowel,
TibetanVowel, TibetanVowel, TibetanVowel, TibetanVowel,
TibetanVowel, TibetanVowel, TibetanVowel, TibetanVowel,
TibetanVowel, TibetanVowel, TibetanVowel, TibetanVowel,
TibetanVowel, TibetanVowel, TibetanVowel, TibetanVowel,
TibetanOther, TibetanOther, TibetanOther, TibetanOther,
TibetanOther, TibetanOther, TibetanOther, TibetanOther,
TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant,
TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant,
TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant,
TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant,
TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant,
TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant,
TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant,
TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant,
TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant,
TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant,
TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant, TibetanSubjoinedConsonant,
TibetanSubjoinedConsonant, TibetanOther, TibetanOther, TibetanOther
};
#define tibetan_form(c) \
(TibetanForm)tibetanForm[c - 0x0f40]
static const HB_OpenTypeFeature tibetan_features[] = {
{ HB_MAKE_TAG('c', 'c', 'm', 'p'), CcmpProperty },
{ HB_MAKE_TAG('a', 'b', 'v', 's'), AboveSubstProperty },
{ HB_MAKE_TAG('b', 'l', 'w', 's'), BelowSubstProperty },
{ HB_MAKE_TAG('c', 'a', 'l', 't'), CaltProperty },
{0, 0}
};
static HB_Bool tibetan_shape_syllable(HB_Bool openType, HB_ShaperItem *item, HB_Bool invalid)
{
hb_uint32 i;
const HB_UChar16 *str = item->string + item->item.pos;
int len = item->item.length;
#ifndef NO_OPENTYPE
const int availableGlyphs = item->num_glyphs;
#endif
HB_Bool haveGlyphs;
HB_STACKARRAY(HB_UChar16, reordered, len + 4);
if (item->num_glyphs < item->item.length + 4) {
item->num_glyphs = item->item.length + 4;
return FALSE;
}
if (invalid) {
*reordered = 0x25cc;
memcpy(reordered+1, str, len*sizeof(HB_UChar16));
len++;
str = reordered;
}
haveGlyphs = item->font->klass->convertStringToGlyphIndices(item->font,
str, len,
item->glyphs, &item->num_glyphs,
item->item.bidiLevel % 2);
HB_FREE_STACKARRAY(reordered);
if (!haveGlyphs)
return FALSE;
for (i = 0; i < item->item.length; i++) {
item->attributes[i].mark = FALSE;
item->attributes[i].clusterStart = FALSE;
item->attributes[i].justification = 0;
item->attributes[i].zeroWidth = FALSE;
/* IDEBUG(" %d: %4x", i, str[i]); */
}
/* now we have the syllable in the right order, and can start running it through open type. */
#ifndef NO_OPENTYPE
if (openType) {
HB_OpenTypeShape(item, /*properties*/0);
if (!HB_OpenTypePosition(item, availableGlyphs, /*doLogClusters*/FALSE))
return FALSE;
}
#endif
item->attributes[0].clusterStart = TRUE;
return TRUE;
}
static int tibetan_nextSyllableBoundary(const HB_UChar16 *s, int start, int end, HB_Bool *invalid)
{
const HB_UChar16 *uc = s + start;
int pos = 0;
TibetanForm state = tibetan_form(*uc);
/* qDebug("state[%d]=%d (uc=%4x)", pos, state, uc[pos]);*/
pos++;
if (state != TibetanHeadConsonant) {
if (state != TibetanOther)
*invalid = TRUE;
goto finish;
}
while (pos < end - start) {
TibetanForm newState = tibetan_form(uc[pos]);
switch(newState) {
case TibetanSubjoinedConsonant:
case TibetanSubjoinedVowel:
if (state != TibetanHeadConsonant &&
state != TibetanSubjoinedConsonant)
goto finish;
state = newState;
break;
case TibetanVowel:
if (state != TibetanHeadConsonant &&
state != TibetanSubjoinedConsonant &&
state != TibetanSubjoinedVowel)
goto finish;
break;
case TibetanOther:
case TibetanHeadConsonant:
goto finish;
}
pos++;
}
finish:
*invalid = FALSE;
return start+pos;
}
HB_Bool HB_TibetanShape(HB_ShaperItem *item)
{
HB_Bool openType = FALSE;
unsigned short *logClusters = item->log_clusters;
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_Tibetan);
#ifndef QT_NO_OPENTYPE
openType = HB_SelectScript(item, tibetan_features);
#endif
while (sstart < end) {
HB_Bool invalid;
int i;
int send = tibetan_nextSyllableBoundary(item->string, sstart, end, &invalid);
/* IDEBUG("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 (!tibetan_shape_syllable(openType, &syllable, invalid)) {
item->num_glyphs += syllable.num_glyphs;
return FALSE;
}
/* fix logcluster array */
for (i = sstart; i < send; ++i)
logClusters[i-item->item.pos] = first_glyph;
sstart = send;
first_glyph += syllable.num_glyphs;
}
item->num_glyphs = first_glyph;
return TRUE;
}
void HB_TibetanAttributes(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;
attributes += from;
while (i < len) {
HB_Bool invalid;
hb_uint32 boundary = tibetan_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);
}
}
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