1 files changed, 274 insertions, 0 deletions
diff --git a/third_party/harfbuzz/src/harfbuzz-tibetan.c b/third_party/harfbuzz/src/harfbuzz-tibetan.c
new file mode 100644
index 0000000..bfa31b1d
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+++ b/third_party/harfbuzz/src/harfbuzz-tibetan.c
@@ -0,0 +1,274 @@
+/*
+ * 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>
+
+/*
+ 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;
+    } else {
+        HB_HeuristicPosition(item);
+    }
+#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;
+    HB_UNUSED(script);
+    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);
+    }
+}
+
+