Initial import from the monolithic Qt.

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Branched from the monolithic repo, Qt master branch, at commit
896db169ea224deb96c59ce8af800d019de63f12

1 files changed, 1367 insertions, 0 deletions

diff --git a/src/3rdparty/harfbuzz/src/harfbuzz-shaper.cpp b/src/3rdparty/harfbuzz/src/harfbuzz-shaper.cpp
new file mode 100644
index 0000000000..c202e1f52b
--- /dev/null
+++ b/src/3rdparty/harfbuzz/src/harfbuzz-shaper.cpp
@@ -0,0 +1,1367 @@
+/*
+ * 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 "harfbuzz-stream-private.h"
+#include <assert.h>
+#include <stdio.h>
+
+#define HB_MIN(a, b) ((a) < (b) ? (a) : (b))
+#define HB_MAX(a, b) ((a) > (b) ? (a) : (b))
+
+// -----------------------------------------------------------------------------------------------------
+//
+// The line break algorithm. See http://www.unicode.org/reports/tr14/tr14-13.html
+//
+// -----------------------------------------------------------------------------------------------------
+
+/* The Unicode algorithm does in our opinion allow line breaks at some
+   places they shouldn't be allowed. The following changes were thus
+   made in comparison to the Unicode reference:
+
+   EX->AL from DB to IB
+   SY->AL from DB to IB
+   SY->PO from DB to IB
+   SY->PR from DB to IB
+   SY->OP from DB to IB
+   AL->PR from DB to IB
+   AL->PO from DB to IB
+   PR->PR from DB to IB
+   PO->PO from DB to IB
+   PR->PO from DB to IB
+   PO->PR from DB to IB
+   HY->PO from DB to IB
+   HY->PR from DB to IB
+   HY->OP from DB to IB
+   NU->EX from PB to IB
+   EX->PO from DB to IB
+*/
+
+// The following line break classes are not treated by the table:
+//  AI, BK, CB, CR, LF, NL, SA, SG, SP, XX
+
+enum break_class {
+    // the first 4 values have to agree with the enum in QCharAttributes
+    ProhibitedBreak,            // PB in table
+    DirectBreak,                // DB in table
+    IndirectBreak,              // IB in table
+    CombiningIndirectBreak,     // CI in table
+    CombiningProhibitedBreak    // CP in table
+};
+#define DB DirectBreak
+#define IB IndirectBreak
+#define CI CombiningIndirectBreak
+#define CP CombiningProhibitedBreak
+#define PB ProhibitedBreak
+
+static const hb_uint8 breakTable[HB_LineBreak_JT+1][HB_LineBreak_JT+1] =
+{
+/*          OP  CL  QU  GL  NS  EX  SY  IS  PR  PO  NU  AL  ID  IN  HY  BA  BB  B2  ZW  CM  WJ  H2  H3  JL  JV  JT */
+/* OP */ { PB, PB, PB, PB, PB, PB, PB, PB, PB, PB, PB, PB, PB, PB, PB, PB, PB, PB, PB, CP, PB, PB, PB, PB, PB, PB },
+/* CL */ { DB, PB, IB, IB, PB, PB, PB, PB, IB, IB, IB, IB, DB, DB, IB, IB, DB, DB, PB, CI, PB, DB, DB, DB, DB, DB },
+/* QU */ { PB, PB, IB, IB, IB, PB, PB, PB, IB, IB, IB, IB, IB, IB, IB, IB, IB, IB, PB, CI, PB, IB, IB, IB, IB, IB },
+/* GL */ { IB, PB, IB, IB, IB, PB, PB, PB, IB, IB, IB, IB, IB, IB, IB, IB, IB, IB, PB, CI, PB, IB, IB, IB, IB, IB },
+/* NS */ { DB, PB, IB, IB, IB, PB, PB, PB, DB, DB, DB, DB, DB, DB, IB, IB, DB, DB, PB, CI, PB, DB, DB, DB, DB, DB },
+/* EX */ { DB, PB, IB, IB, IB, PB, PB, PB, DB, IB, DB, IB, DB, DB, IB, IB, DB, DB, PB, CI, PB, DB, DB, DB, DB, DB },
+/* SY */ { IB, PB, IB, IB, IB, PB, PB, PB, IB, IB, IB, IB, DB, DB, IB, IB, DB, DB, PB, CI, PB, DB, DB, DB, DB, DB },
+/* IS */ { DB, PB, IB, IB, IB, PB, PB, PB, DB, DB, IB, IB, DB, DB, IB, IB, DB, DB, PB, CI, PB, DB, DB, DB, DB, DB },
+/* PR */ { IB, PB, IB, IB, IB, PB, PB, PB, IB, IB, IB, IB, IB, DB, IB, IB, DB, DB, PB, CI, PB, IB, IB, IB, IB, IB },
+/* PO */ { IB, PB, IB, IB, IB, PB, PB, PB, IB, IB, IB, IB, DB, DB, IB, IB, DB, DB, PB, CI, PB, DB, DB, DB, DB, DB },
+/* NU */ { IB, PB, IB, IB, IB, IB, PB, PB, IB, IB, IB, IB, DB, IB, IB, IB, DB, DB, PB, CI, PB, DB, DB, DB, DB, DB },
+/* AL */ { IB, PB, IB, IB, IB, PB, PB, PB, IB, IB, IB, IB, DB, IB, IB, IB, DB, DB, PB, CI, PB, DB, DB, DB, DB, DB },
+/* ID */ { DB, PB, IB, IB, IB, PB, PB, PB, DB, IB, DB, DB, DB, IB, IB, IB, DB, DB, PB, CI, PB, DB, DB, DB, DB, DB },
+/* IN */ { DB, PB, IB, IB, IB, PB, PB, PB, DB, DB, DB, DB, DB, IB, IB, IB, DB, DB, PB, CI, PB, DB, DB, DB, DB, DB },
+/* HY */ { IB, PB, IB, IB, IB, PB, PB, PB, IB, IB, IB, DB, DB, DB, IB, IB, DB, DB, PB, CI, PB, DB, DB, DB, DB, DB },
+/* BA */ { DB, PB, IB, IB, IB, PB, PB, PB, DB, DB, DB, DB, DB, DB, IB, IB, DB, DB, PB, CI, PB, DB, DB, DB, DB, DB },
+/* BB */ { IB, PB, IB, IB, IB, PB, PB, PB, IB, IB, IB, IB, IB, IB, IB, IB, IB, IB, PB, CI, PB, IB, IB, IB, IB, IB },
+/* B2 */ { DB, PB, IB, IB, IB, PB, PB, PB, DB, DB, DB, DB, DB, DB, IB, IB, DB, PB, PB, CI, PB, DB, DB, DB, DB, DB },
+/* ZW */ { DB, DB, DB, DB, DB, DB, DB, DB, DB, DB, DB, DB, DB, DB, DB, DB, DB, DB, PB, DB, DB, DB, DB, DB, DB, DB },
+/* CM */ { DB, PB, IB, IB, IB, PB, PB, PB, DB, DB, IB, IB, DB, IB, IB, IB, DB, DB, PB, CI, PB, DB, DB, DB, DB, DB },
+/* WJ */ { IB, PB, IB, IB, IB, PB, PB, PB, IB, IB, IB, IB, IB, IB, IB, IB, IB, IB, PB, CI, PB, IB, IB, IB, IB, IB },
+/* H2 */ { DB, PB, IB, IB, IB, PB, PB, PB, DB, IB, DB, DB, DB, IB, IB, IB, DB, DB, PB, CI, PB, DB, DB, DB, IB, IB },
+/* H3 */ { DB, PB, IB, IB, IB, PB, PB, PB, DB, IB, DB, DB, DB, IB, IB, IB, DB, DB, PB, CI, PB, DB, DB, DB, DB, IB },
+/* JL */ { DB, PB, IB, IB, IB, PB, PB, PB, DB, IB, DB, DB, DB, IB, IB, IB, DB, DB, PB, CI, PB, IB, IB, IB, IB, DB },
+/* JV */ { DB, PB, IB, IB, IB, PB, PB, PB, DB, IB, DB, DB, DB, IB, IB, IB, DB, DB, PB, CI, PB, DB, DB, DB, IB, IB },
+/* JT */ { DB, PB, IB, IB, IB, PB, PB, PB, DB, IB, DB, DB, DB, IB, IB, IB, DB, DB, PB, CI, PB, DB, DB, DB, DB, IB }
+};
+#undef DB
+#undef IB
+#undef CI
+#undef CP
+#undef PB
+
+static const hb_uint8 graphemeTable[HB_Grapheme_LVT + 1][HB_Grapheme_LVT + 1] =
+{
+//      Other, CR,    LF,    Control,Extend,L,    V,     T,     LV,    LVT
+    { true , true , true , true , true , true , true , true , true , true  }, // Other, 
+    { true , true , true , true , true , true , true , true , true , true  }, // CR,
+    { true , false, true , true , true , true , true , true , true , true  }, // LF,
+    { true , true , true , true , true , true , true , true , true , true  }, // Control,
+    { false, true , true , true , false, false, false, false, false, false }, // Extend,
+    { true , true , true , true , true , false, true , true , true , true  }, // L, 
+    { true , true , true , true , true , false, false, true , false, true  }, // V, 
+    { true , true , true , true , true , true , false, false, false, false }, // T, 
+    { true , true , true , true , true , false, true , true , true , true  }, // LV, 
+    { true , true , true , true , true , false, true , true , true , true  }, // LVT
+};
+    
+static void calcLineBreaks(const HB_UChar16 *uc, hb_uint32 len, HB_CharAttributes *charAttributes)
+{
+    if (!len)
+        return;
+
+    // ##### can this fail if the first char is a surrogate?
+    HB_LineBreakClass cls;
+    HB_GraphemeClass grapheme;
+    HB_GetGraphemeAndLineBreakClass(*uc, &grapheme, &cls);
+    // handle case where input starts with an LF
+    if (cls == HB_LineBreak_LF)
+        cls = HB_LineBreak_BK;
+
+    charAttributes[0].whiteSpace = (cls == HB_LineBreak_SP || cls == HB_LineBreak_BK);
+    charAttributes[0].charStop = true;
+
+    int lcls = cls;
+    for (hb_uint32 i = 1; i < len; ++i) {
+        charAttributes[i].whiteSpace = false;
+        charAttributes[i].charStop = true;
+
+        HB_UChar32 code = uc[i];
+        HB_GraphemeClass ngrapheme;
+        HB_LineBreakClass ncls;
+        HB_GetGraphemeAndLineBreakClass(code, &ngrapheme, &ncls);
+        charAttributes[i].charStop = graphemeTable[ngrapheme][grapheme];
+        // handle surrogates
+        if (ncls == HB_LineBreak_SG) {
+            if (HB_IsHighSurrogate(uc[i]) && i < len - 1 && HB_IsLowSurrogate(uc[i+1])) {
+                continue;
+            } else if (HB_IsLowSurrogate(uc[i]) && HB_IsHighSurrogate(uc[i-1])) {
+                code = HB_SurrogateToUcs4(uc[i-1], uc[i]);
+                HB_GetGraphemeAndLineBreakClass(code, &ngrapheme, &ncls);
+                charAttributes[i].charStop = false;
+            } else {
+                ncls = HB_LineBreak_AL;
+            }
+        }
+
+        // set white space and char stop flag
+        if (ncls >= HB_LineBreak_SP)
+            charAttributes[i].whiteSpace = true;
+
+        HB_LineBreakType lineBreakType = HB_NoBreak;
+        if (cls >= HB_LineBreak_LF) {
+            lineBreakType = HB_ForcedBreak;
+        } else if(cls == HB_LineBreak_CR) {
+            lineBreakType = (ncls == HB_LineBreak_LF) ? HB_NoBreak : HB_ForcedBreak;
+        }
+
+        if (ncls == HB_LineBreak_SP)
+            goto next_no_cls_update;
+        if (ncls >= HB_LineBreak_CR)
+            goto next;
+
+        {
+            int tcls = ncls;
+            // for south east asian chars that require a complex (dictionary analysis), the unicode
+            // standard recommends to treat them as AL. thai_attributes and other attribute methods that
+            // do dictionary analysis can override
+            if (tcls >= HB_LineBreak_SA)
+                tcls = HB_LineBreak_AL;
+            if (cls >= HB_LineBreak_SA)
+                cls = HB_LineBreak_AL;
+
+            int brk = breakTable[cls][tcls];
+            switch (brk) {
+            case DirectBreak:
+                lineBreakType = HB_Break;
+                if (uc[i-1] == 0xad) // soft hyphen
+                    lineBreakType = HB_SoftHyphen;
+                break;
+            case IndirectBreak:
+                lineBreakType = (lcls == HB_LineBreak_SP) ? HB_Break : HB_NoBreak;
+                break;
+            case CombiningIndirectBreak:
+                lineBreakType = HB_NoBreak;
+                if (lcls == HB_LineBreak_SP){
+                    if (i > 1)
+                        charAttributes[i-2].lineBreakType = HB_Break;
+                } else {
+                    goto next_no_cls_update;
+                }
+                break;
+            case CombiningProhibitedBreak:
+                lineBreakType = HB_NoBreak;
+                if (lcls != HB_LineBreak_SP)
+                    goto next_no_cls_update;
+            case ProhibitedBreak:
+            default:
+                break;
+            }
+        }
+    next:
+        cls = ncls;
+    next_no_cls_update:
+        lcls = ncls;
+        grapheme = ngrapheme;
+        charAttributes[i-1].lineBreakType = lineBreakType;
+    }
+    charAttributes[len-1].lineBreakType = HB_ForcedBreak;
+}
+
+// --------------------------------------------------------------------------------------------------------------------------------------------
+//
+// Basic processing
+//
+// --------------------------------------------------------------------------------------------------------------------------------------------
+
+static inline void positionCluster(HB_ShaperItem *item, int gfrom,  int glast)
+{
+    int nmarks = glast - gfrom;
+    assert(nmarks > 0);
+
+    HB_Glyph *glyphs = item->glyphs;
+    HB_GlyphAttributes *attributes = item->attributes;
+
+    HB_GlyphMetrics baseMetrics;
+    item->font->klass->getGlyphMetrics(item->font, glyphs[gfrom], &baseMetrics);
+
+    if (item->item.script == HB_Script_Hebrew
+        && (-baseMetrics.y) > baseMetrics.height)
+        // we need to attach below the baseline, because of the hebrew iud.
+        baseMetrics.height = -baseMetrics.y;
+
+//     qDebug("---> positionCluster: cluster from %d to %d", gfrom, glast);
+//     qDebug("baseInfo: %f/%f (%f/%f) off=%f/%f", baseInfo.x, baseInfo.y, baseInfo.width, baseInfo.height, baseInfo.xoff, baseInfo.yoff);
+
+    HB_Fixed size = item->font->klass->getFontMetric(item->font, HB_FontAscent) / 10;
+    HB_Fixed offsetBase = HB_FIXED_CONSTANT(1) + (size - HB_FIXED_CONSTANT(4)) / 4;
+    if (size > HB_FIXED_CONSTANT(4))
+        offsetBase += HB_FIXED_CONSTANT(4);
+    else
+        offsetBase += size;
+    //qreal offsetBase = (size - 4) / 4 + qMin<qreal>(size, 4) + 1;
+//     qDebug("offset = %f", offsetBase);
+
+    bool rightToLeft = item->item.bidiLevel % 2;
+
+    int i;
+    unsigned char lastCmb = 0;
+    HB_GlyphMetrics attachmentRect;
+    memset(&attachmentRect, 0, sizeof(attachmentRect));
+
+    for(i = 1; i <= nmarks; i++) {
+        HB_Glyph mark = glyphs[gfrom+i];
+        HB_GlyphMetrics markMetrics;
+        item->font->klass->getGlyphMetrics(item->font, mark, &markMetrics);
+        HB_FixedPoint p;
+        p.x = p.y = 0;
+//          qDebug("markInfo: %f/%f (%f/%f) off=%f/%f", markInfo.x, markInfo.y, markInfo.width, markInfo.height, markInfo.xoff, markInfo.yoff);
+
+        HB_Fixed offset = offsetBase;
+        unsigned char cmb = attributes[gfrom+i].combiningClass;
+
+        // ### maybe the whole position determination should move down to heuristicSetGlyphAttributes. Would save some
+        // bits  in the glyphAttributes structure.
+        if (cmb < 200) {
+            // fixed position classes. We approximate by mapping to one of the others.
+            // currently I added only the ones for arabic, hebrew, lao and thai.
+
+            // for Lao and Thai marks with class 0, see below (heuristicSetGlyphAttributes)
+
+            // add a bit more offset to arabic, a bit hacky
+            if (cmb >= 27 && cmb <= 36 && offset < 3)
+                offset +=1;
+            // below
+            if ((cmb >= 10 && cmb <= 18) ||
+                 cmb == 20 || cmb == 22 ||
+                 cmb == 29 || cmb == 32)
+                cmb = HB_Combining_Below;
+            // above
+            else if (cmb == 23 || cmb == 27 || cmb == 28 ||
+                      cmb == 30 || cmb == 31 || (cmb >= 33 && cmb <= 36))
+                cmb = HB_Combining_Above;
+            //below-right
+            else if (cmb == 9 || cmb == 103 || cmb == 118)
+                cmb = HB_Combining_BelowRight;
+            // above-right
+            else if (cmb == 24 || cmb == 107 || cmb == 122)
+                cmb = HB_Combining_AboveRight;
+            else if (cmb == 25)
+                cmb = HB_Combining_AboveLeft;
+            // fixed:
+            //  19 21
+
+        }
+
+        // combining marks of different class don't interact. Reset the rectangle.
+        if (cmb != lastCmb) {
+            //qDebug("resetting rect");
+            attachmentRect = baseMetrics;
+        }
+
+        switch(cmb) {
+        case HB_Combining_DoubleBelow:
+                // ### wrong in rtl context!
+        case HB_Combining_BelowLeft:
+            p.y += offset;
+        case HB_Combining_BelowLeftAttached:
+            p.x += attachmentRect.x - markMetrics.x;
+            p.y += (attachmentRect.y + attachmentRect.height) - markMetrics.y;
+            break;
+        case HB_Combining_Below:
+            p.y += offset;
+        case HB_Combining_BelowAttached:
+            p.x += attachmentRect.x - markMetrics.x;
+            p.y += (attachmentRect.y + attachmentRect.height) - markMetrics.y;
+
+            p.x += (attachmentRect.width - markMetrics.width) / 2;
+            break;
+        case HB_Combining_BelowRight:
+            p.y += offset;
+        case HB_Combining_BelowRightAttached:
+            p.x += attachmentRect.x + attachmentRect.width - markMetrics.width - markMetrics.x;
+            p.y += attachmentRect.y + attachmentRect.height - markMetrics.y;
+            break;
+        case HB_Combining_Left:
+            p.x -= offset;
+        case HB_Combining_LeftAttached:
+            break;
+        case HB_Combining_Right:
+            p.x += offset;
+        case HB_Combining_RightAttached:
+            break;
+        case HB_Combining_DoubleAbove:
+            // ### wrong in RTL context!
+        case HB_Combining_AboveLeft:
+            p.y -= offset;
+        case HB_Combining_AboveLeftAttached:
+            p.x += attachmentRect.x - markMetrics.x;
+            p.y += attachmentRect.y - markMetrics.y - markMetrics.height;
+            break;
+        case HB_Combining_Above:
+            p.y -= offset;
+        case HB_Combining_AboveAttached:
+            p.x += attachmentRect.x - markMetrics.x;
+            p.y += attachmentRect.y - markMetrics.y - markMetrics.height;
+
+            p.x += (attachmentRect.width - markMetrics.width) / 2;
+            break;
+        case HB_Combining_AboveRight:
+            p.y -= offset;
+        case HB_Combining_AboveRightAttached:
+            p.x += attachmentRect.x + attachmentRect.width - markMetrics.x - markMetrics.width;
+            p.y += attachmentRect.y - markMetrics.y - markMetrics.height;
+            break;
+
+        case HB_Combining_IotaSubscript:
+            default:
+                break;
+        }
+//          qDebug("char=%x combiningClass = %d offset=%f/%f", mark, cmb, p.x(), p.y());
+        markMetrics.x += p.x;
+        markMetrics.y += p.y;
+
+        HB_GlyphMetrics unitedAttachmentRect = attachmentRect;
+        unitedAttachmentRect.x = HB_MIN(attachmentRect.x, markMetrics.x);
+        unitedAttachmentRect.y = HB_MIN(attachmentRect.y, markMetrics.y);
+        unitedAttachmentRect.width = HB_MAX(attachmentRect.x + attachmentRect.width, markMetrics.x + markMetrics.width) - unitedAttachmentRect.x;
+        unitedAttachmentRect.height = HB_MAX(attachmentRect.y + attachmentRect.height, markMetrics.y + markMetrics.height) - unitedAttachmentRect.y;
+        attachmentRect = unitedAttachmentRect;
+
+        lastCmb = cmb;
+        if (rightToLeft) {
+            item->offsets[gfrom+i].x = p.x;
+            item->offsets[gfrom+i].y = p.y;
+        } else {
+            item->offsets[gfrom+i].x = p.x - baseMetrics.xOffset;
+            item->offsets[gfrom+i].y = p.y - baseMetrics.yOffset;
+        }
+        item->advances[gfrom+i] = 0;
+    }
+}
+
+void HB_HeuristicPosition(HB_ShaperItem *item)
+{
+    HB_GetGlyphAdvances(item);
+    HB_GlyphAttributes *attributes = item->attributes;
+
+    int cEnd = -1;
+    int i = item->num_glyphs;
+    while (i--) {
+        if (cEnd == -1 && attributes[i].mark) {
+            cEnd = i;
+        } else if (cEnd != -1 && !attributes[i].mark) {
+            positionCluster(item, i, cEnd);
+            cEnd = -1;
+        }
+    }
+}
+
+// set the glyph attributes heuristically. Assumes a 1 to 1 relationship between chars and glyphs
+// and no reordering.
+// also computes logClusters heuristically
+void HB_HeuristicSetGlyphAttributes(HB_ShaperItem *item)
+{
+    const HB_UChar16 *uc = item->string + item->item.pos;
+    hb_uint32 length = item->item.length;
+
+    // ### zeroWidth and justification are missing here!!!!!
+
+    assert(item->num_glyphs <= length);
+
+//     qDebug("QScriptEngine::heuristicSetGlyphAttributes, num_glyphs=%d", item->num_glyphs);
+    HB_GlyphAttributes *attributes = item->attributes;
+    unsigned short *logClusters = item->log_clusters;
+
+    hb_uint32 glyph_pos = 0;
+    hb_uint32 i;
+    for (i = 0; i < length; i++) {
+        if (HB_IsHighSurrogate(uc[i]) && i < length - 1
+            && HB_IsLowSurrogate(uc[i + 1])) {
+            logClusters[i] = glyph_pos;
+            logClusters[++i] = glyph_pos;
+        } else {
+            logClusters[i] = glyph_pos;
+        }
+        ++glyph_pos;
+    }
+    assert(glyph_pos == item->num_glyphs);
+
+    // first char in a run is never (treated as) a mark
+    int cStart = 0;
+    const bool symbolFont = item->face->isSymbolFont;
+    attributes[0].mark = false;
+    attributes[0].clusterStart = true;
+    attributes[0].dontPrint = (!symbolFont && uc[0] == 0x00ad) || HB_IsControlChar(uc[0]);
+
+    int pos = 0;
+    HB_CharCategory lastCat;
+    int dummy;
+    HB_GetUnicodeCharProperties(uc[0], &lastCat, &dummy);
+    for (i = 1; i < length; ++i) {
+        if (logClusters[i] == pos)
+            // same glyph
+            continue;
+        ++pos;
+        while (pos < logClusters[i]) {
+            attributes[pos] = attributes[pos-1];
+            ++pos;
+        }
+        // hide soft-hyphens by default
+        if ((!symbolFont && uc[i] == 0x00ad) || HB_IsControlChar(uc[i]))
+            attributes[pos].dontPrint = true;
+        HB_CharCategory cat;
+        int cmb;
+        HB_GetUnicodeCharProperties(uc[i], &cat, &cmb);
+        if (cat != HB_Mark_NonSpacing) {
+            attributes[pos].mark = false;
+            attributes[pos].clusterStart = true;
+            attributes[pos].combiningClass = 0;
+            cStart = logClusters[i];
+        } else {
+            if (cmb == 0) {
+                // Fix 0 combining classes
+                if ((uc[pos] & 0xff00) == 0x0e00) {
+                    // thai or lao
+                    if (uc[pos] == 0xe31 ||
+                         uc[pos] == 0xe34 ||
+                         uc[pos] == 0xe35 ||
+                         uc[pos] == 0xe36 ||
+                         uc[pos] == 0xe37 ||
+                         uc[pos] == 0xe47 ||
+                         uc[pos] == 0xe4c ||
+                         uc[pos] == 0xe4d ||
+                         uc[pos] == 0xe4e) {
+                        cmb = HB_Combining_AboveRight;
+                    } else if (uc[pos] == 0xeb1 ||
+                                uc[pos] == 0xeb4 ||
+                                uc[pos] == 0xeb5 ||
+                                uc[pos] == 0xeb6 ||
+                                uc[pos] == 0xeb7 ||
+                                uc[pos] == 0xebb ||
+                                uc[pos] == 0xecc ||
+                                uc[pos] == 0xecd) {
+                        cmb = HB_Combining_Above;
+                    } else if (uc[pos] == 0xebc) {
+                        cmb = HB_Combining_Below;
+                    }
+                }
+            }
+
+            attributes[pos].mark = true;
+            attributes[pos].clusterStart = false;
+            attributes[pos].combiningClass = cmb;
+            logClusters[i] = cStart;
+        }
+        // one gets an inter character justification point if the current char is not a non spacing mark.
+        // as then the current char belongs to the last one and one gets a space justification point
+        // after the space char.
+        if (lastCat == HB_Separator_Space)
+            attributes[pos-1].justification = HB_Space;
+        else if (cat != HB_Mark_NonSpacing)
+            attributes[pos-1].justification = HB_Character;
+        else
+            attributes[pos-1].justification = HB_NoJustification;
+
+        lastCat = cat;
+    }
+    pos = logClusters[length-1];
+    if (lastCat == HB_Separator_Space)
+        attributes[pos].justification = HB_Space;
+    else
+        attributes[pos].justification = HB_Character;
+}
+
+#ifndef NO_OPENTYPE
+static const HB_OpenTypeFeature basic_features[] = {
+    { HB_MAKE_TAG('c', 'c', 'm', 'p'), CcmpProperty },
+    { HB_MAKE_TAG('l', 'i', 'g', 'a'), LigaProperty },
+    { HB_MAKE_TAG('c', 'l', 'i', 'g'), CligProperty },
+    {0, 0}
+};
+
+static const HB_OpenTypeFeature disabled_features[] = {
+    { HB_MAKE_TAG('c', 'p', 'c', 't'), PositioningProperties },
+    { HB_MAKE_TAG('h', 'a', 'l', 't'), PositioningProperties },
+    // TODO: we need to add certain HB_ShaperFlag for vertical
+    // writing mode to enable these vertical writing features:
+    { HB_MAKE_TAG('v', 'a', 'l', 't'), PositioningProperties },
+    { HB_MAKE_TAG('v', 'h', 'a', 'l'), PositioningProperties },
+    { HB_MAKE_TAG('v', 'k', 'r', 'n'), PositioningProperties },
+    { HB_MAKE_TAG('v', 'p', 'a', 'l'), PositioningProperties },
+    {0, 0}
+};
+#endif
+
+HB_Bool HB_ConvertStringToGlyphIndices(HB_ShaperItem *shaper_item)
+{
+    if (shaper_item->glyphIndicesPresent) {
+        shaper_item->num_glyphs = shaper_item->initialGlyphCount;
+        shaper_item->glyphIndicesPresent = false;
+        return true;
+    }
+    return shaper_item->font->klass
+           ->convertStringToGlyphIndices(shaper_item->font,
+                                         shaper_item->string + shaper_item->item.pos, shaper_item->item.length,
+                                         shaper_item->glyphs, &shaper_item->num_glyphs,
+                                         shaper_item->item.bidiLevel % 2);
+}
+
+HB_Bool HB_BasicShape(HB_ShaperItem *shaper_item)
+{
+#ifndef NO_OPENTYPE
+    const int availableGlyphs = shaper_item->num_glyphs;
+#endif
+
+    if (!HB_ConvertStringToGlyphIndices(shaper_item))
+        return false;
+
+    HB_HeuristicSetGlyphAttributes(shaper_item);
+
+#ifndef NO_OPENTYPE
+    if (HB_SelectScript(shaper_item, basic_features)) {
+        HB_OpenTypeShape(shaper_item, /*properties*/0);
+        return HB_OpenTypePosition(shaper_item, availableGlyphs, /*doLogClusters*/true);
+    }
+#endif
+
+    HB_HeuristicPosition(shaper_item);
+    return true;
+}
+
+const HB_ScriptEngine HB_ScriptEngines[] = {
+    // Common
+    { HB_BasicShape, 0},
+    // Greek
+    { HB_GreekShape, 0},
+    // Cyrillic
+    { HB_BasicShape, 0},
+    // Armenian
+    { HB_BasicShape, 0},
+    // Hebrew
+    { HB_HebrewShape, 0 },
+    // Arabic
+    { HB_ArabicShape, 0},
+    // Syriac
+    { HB_ArabicShape, 0},
+    // Thaana
+    { HB_BasicShape, 0 },
+    // Devanagari
+    { HB_IndicShape, HB_IndicAttributes },
+    // Bengali
+    { HB_IndicShape, HB_IndicAttributes },
+    // Gurmukhi
+    { HB_IndicShape, HB_IndicAttributes },
+    // Gujarati
+    { HB_IndicShape, HB_IndicAttributes },
+    // Oriya
+    { HB_IndicShape, HB_IndicAttributes },
+    // Tamil
+    { HB_IndicShape, HB_IndicAttributes },
+    // Telugu
+    { HB_IndicShape, HB_IndicAttributes },
+    // Kannada
+    { HB_IndicShape, HB_IndicAttributes },
+    // Malayalam
+    { HB_IndicShape, HB_IndicAttributes },
+    // Sinhala
+    { HB_IndicShape, HB_IndicAttributes },
+    // Thai
+    { HB_BasicShape, HB_ThaiAttributes },
+    // Lao
+    { HB_BasicShape, 0 },
+    // Tibetan
+    { HB_TibetanShape, HB_TibetanAttributes },
+    // Myanmar
+    { HB_MyanmarShape, HB_MyanmarAttributes },
+    // Georgian
+    { HB_BasicShape, 0 },
+    // Hangul
+    { HB_HangulShape, 0 },
+    // Ogham
+    { HB_BasicShape, 0 },
+    // Runic
+    { HB_BasicShape, 0 },
+    // Khmer
+    { HB_KhmerShape, HB_KhmerAttributes },
+    // N'Ko
+    { HB_ArabicShape, 0}
+};
+
+void HB_GetCharAttributes(const HB_UChar16 *string, hb_uint32 stringLength,
+                          const HB_ScriptItem *items, hb_uint32 numItems,
+                          HB_CharAttributes *attributes)
+{
+    calcLineBreaks(string, stringLength, attributes);
+
+    for (hb_uint32 i = 0; i < numItems; ++i) {
+        HB_Script script = items[i].script;
+        if (script == HB_Script_Inherited)
+            script = HB_Script_Common;
+        HB_AttributeFunction attributeFunction = HB_ScriptEngines[script].charAttributes;
+        if (!attributeFunction)
+            continue;
+        attributeFunction(script, string, items[i].pos, items[i].length, attributes);
+    }
+}
+
+
+enum BreakRule { NoBreak = 0, Break = 1, Middle = 2 };
+
+static const hb_uint8 wordbreakTable[HB_Word_ExtendNumLet + 1][HB_Word_ExtendNumLet + 1] = {
+//        Other    Format   Katakana ALetter  MidLetter MidNum  Numeric  ExtendNumLet
+    {   Break,   Break,   Break,   Break,   Break,   Break,   Break,   Break }, // Other
+    {   Break,   Break,   Break,   Break,   Break,   Break,   Break,   Break }, // Format 
+    {   Break,   Break, NoBreak,   Break,   Break,   Break,   Break, NoBreak }, // Katakana
+    {   Break,   Break,   Break, NoBreak,  Middle,   Break, NoBreak, NoBreak }, // ALetter
+    {   Break,   Break,   Break,   Break,   Break,   Break,   Break,   Break }, // MidLetter
+    {   Break,   Break,   Break,   Break,   Break,   Break,   Break,   Break }, // MidNum
+    {   Break,   Break,   Break, NoBreak,   Break,  Middle, NoBreak, NoBreak }, // Numeric
+    {   Break,   Break, NoBreak, NoBreak,   Break,   Break, NoBreak, NoBreak }, // ExtendNumLet
+};
+
+void HB_GetWordBoundaries(const HB_UChar16 *string, hb_uint32 stringLength,
+                          const HB_ScriptItem * /*items*/, hb_uint32 /*numItems*/,
+                          HB_CharAttributes *attributes)
+{
+    if (stringLength == 0)
+        return;
+    unsigned int brk = HB_GetWordClass(string[0]);
+    attributes[0].wordBoundary = true;
+    for (hb_uint32 i = 1; i < stringLength; ++i) {
+        if (!attributes[i].charStop) {
+            attributes[i].wordBoundary = false;
+            continue;
+        }
+        hb_uint32 nbrk = HB_GetWordClass(string[i]);
+        if (nbrk == HB_Word_Format) {
+            attributes[i].wordBoundary = (HB_GetSentenceClass(string[i-1]) == HB_Sentence_Sep);
+            continue;
+        }
+        BreakRule rule = (BreakRule)wordbreakTable[brk][nbrk];
+        if (rule == Middle) {
+            rule = Break;
+            hb_uint32 lookahead = i + 1;
+            while (lookahead < stringLength) {
+                hb_uint32 testbrk = HB_GetWordClass(string[lookahead]);
+                if (testbrk == HB_Word_Format && HB_GetSentenceClass(string[lookahead]) != HB_Sentence_Sep) {
+                    ++lookahead;
+                    continue;
+                }
+                if (testbrk == brk) {
+                    rule = NoBreak;
+                    while (i < lookahead)
+                        attributes[i++].wordBoundary = false;
+                    nbrk = testbrk;
+                }
+                break;
+            }
+        }
+        attributes[i].wordBoundary = (rule == Break);
+        brk = nbrk;
+    }
+}
+
+
+enum SentenceBreakStates {
+    SB_Initial,
+    SB_Upper,
+    SB_UpATerm, 
+    SB_ATerm,
+    SB_ATermC, 
+    SB_ACS, 
+    SB_STerm, 
+    SB_STermC, 
+    SB_SCS,
+    SB_BAfter, 
+    SB_Break,
+    SB_Look
+};
+
+static const hb_uint8 sentenceBreakTable[HB_Sentence_Close + 1][HB_Sentence_Close + 1] = {
+//        Other       Sep         Format      Sp          Lower       Upper       OLetter     Numeric     ATerm       STerm       Close
+      { SB_Initial, SB_BAfter , SB_Initial, SB_Initial, SB_Initial, SB_Upper  , SB_Initial, SB_Initial, SB_ATerm  , SB_STerm  , SB_Initial }, // SB_Initial,
+      { SB_Initial, SB_BAfter , SB_Upper  , SB_Initial, SB_Initial, SB_Upper  , SB_Initial, SB_Initial, SB_UpATerm, SB_STerm  , SB_Initial }, // SB_Upper
+      
+      { SB_Look   , SB_BAfter , SB_UpATerm, SB_ACS    , SB_Initial, SB_Upper  , SB_Break  , SB_Initial, SB_ATerm  , SB_STerm  , SB_ATermC  }, // SB_UpATerm
+      { SB_Look   , SB_BAfter , SB_ATerm  , SB_ACS    , SB_Initial, SB_Break  , SB_Break  , SB_Initial, SB_ATerm  , SB_STerm  , SB_ATermC  }, // SB_ATerm
+      { SB_Look   , SB_BAfter , SB_ATermC , SB_ACS    , SB_Initial, SB_Break  , SB_Break  , SB_Look   , SB_ATerm  , SB_STerm  , SB_ATermC  }, // SB_ATermC,
+      { SB_Look   , SB_BAfter , SB_ACS    , SB_ACS    , SB_Initial, SB_Break  , SB_Break  , SB_Look   , SB_ATerm  , SB_STerm  , SB_Look    }, // SB_ACS,
+      
+      { SB_Break  , SB_BAfter , SB_STerm  , SB_SCS    , SB_Break  , SB_Break  , SB_Break  , SB_Break  , SB_ATerm  , SB_STerm  , SB_STermC  }, // SB_STerm,
+      { SB_Break  , SB_BAfter , SB_STermC , SB_SCS    , SB_Break  , SB_Break  , SB_Break  , SB_Break  , SB_ATerm  , SB_STerm  , SB_STermC  }, // SB_STermC,
+      { SB_Break  , SB_BAfter , SB_SCS    , SB_SCS    , SB_Break  , SB_Break  , SB_Break  , SB_Break  , SB_ATerm  , SB_STerm  , SB_Break   }, // SB_SCS,
+      { SB_Break  , SB_Break  , SB_Break  , SB_Break  , SB_Break  , SB_Break  , SB_Break  , SB_Break  , SB_Break  , SB_Break  , SB_Break   }, // SB_BAfter,
+};
+
+void HB_GetSentenceBoundaries(const HB_UChar16 *string, hb_uint32 stringLength,
+                              const HB_ScriptItem * /*items*/, hb_uint32 /*numItems*/,
+                              HB_CharAttributes *attributes)
+{
+    if (stringLength == 0)
+        return;
+    hb_uint32 brk = sentenceBreakTable[SB_Initial][HB_GetSentenceClass(string[0])];
+    attributes[0].sentenceBoundary = true;
+    for (hb_uint32 i = 1; i < stringLength; ++i) {
+        if (!attributes[i].charStop) {
+            attributes[i].sentenceBoundary = false;
+            continue;
+        }
+        brk = sentenceBreakTable[brk][HB_GetSentenceClass(string[i])];
+        if (brk == SB_Look) {
+            brk = SB_Break;
+            hb_uint32 lookahead = i + 1;
+            while (lookahead < stringLength) {
+                hb_uint32 sbrk = HB_GetSentenceClass(string[lookahead]);
+                if (sbrk != HB_Sentence_Other && sbrk != HB_Sentence_Numeric && sbrk != HB_Sentence_Close) {
+                    break;
+                } else if (sbrk == HB_Sentence_Lower) {
+                    brk = SB_Initial;
+                    break;
+                }
+                ++lookahead;
+            }
+            if (brk == SB_Initial) {
+                while (i < lookahead)
+                    attributes[i++].sentenceBoundary = false;
+            }
+        }
+        if (brk == SB_Break) {
+            attributes[i].sentenceBoundary = true;
+            brk = sentenceBreakTable[SB_Initial][HB_GetSentenceClass(string[i])];
+        } else {
+            attributes[i].sentenceBoundary = false;
+        }
+    }
+}
+
+
+static inline char *tag_to_string(HB_UInt tag)
+{
+    static char string[5];
+    string[0] = (tag >> 24)&0xff;
+    string[1] = (tag >> 16)&0xff;
+    string[2] = (tag >> 8)&0xff;
+    string[3] = tag&0xff;
+    string[4] = 0;
+    return string;
+}
+
+#ifdef OT_DEBUG
+static void dump_string(HB_Buffer buffer)
+{
+    for (uint i = 0; i < buffer->in_length; ++i) {
+        qDebug("    %x: cluster=%d", buffer->in_string[i].gindex, buffer->in_string[i].cluster);
+    }
+}
+#define DEBUG printf
+#else
+#define DEBUG if (1) ; else printf
+#endif
+
+#define DefaultLangSys 0xffff
+#define DefaultScript HB_MAKE_TAG('D', 'F', 'L', 'T')
+
+enum {
+    RequiresGsub = 1,
+    RequiresGpos = 2
+};
+
+struct OTScripts {
+    unsigned int tag;
+    int flags;
+};
+static const OTScripts ot_scripts [] = {
+    // Common
+    { HB_MAKE_TAG('l', 'a', 't', 'n'), 0 },
+    // Greek
+    { HB_MAKE_TAG('g', 'r', 'e', 'k'), 0 },
+    // Cyrillic
+    { HB_MAKE_TAG('c', 'y', 'r', 'l'), 0 },
+    // Armenian
+    { HB_MAKE_TAG('a', 'r', 'm', 'n'), 0 },
+    // Hebrew
+    { HB_MAKE_TAG('h', 'e', 'b', 'r'), 1 },
+    // Arabic
+    { HB_MAKE_TAG('a', 'r', 'a', 'b'), 1 },
+    // Syriac
+    { HB_MAKE_TAG('s', 'y', 'r', 'c'), 1 },
+    // Thaana
+    { HB_MAKE_TAG('t', 'h', 'a', 'a'), 1 },
+    // Devanagari
+    { HB_MAKE_TAG('d', 'e', 'v', 'a'), 1 },
+    // Bengali
+    { HB_MAKE_TAG('b', 'e', 'n', 'g'), 1 },
+    // Gurmukhi
+    { HB_MAKE_TAG('g', 'u', 'r', 'u'), 1 },
+    // Gujarati
+    { HB_MAKE_TAG('g', 'u', 'j', 'r'), 1 },
+    // Oriya
+    { HB_MAKE_TAG('o', 'r', 'y', 'a'), 1 },
+    // Tamil
+    { HB_MAKE_TAG('t', 'a', 'm', 'l'), 1 },
+    // Telugu
+    { HB_MAKE_TAG('t', 'e', 'l', 'u'), 1 },
+    // Kannada
+    { HB_MAKE_TAG('k', 'n', 'd', 'a'), 1 },
+    // Malayalam
+    { HB_MAKE_TAG('m', 'l', 'y', 'm'), 1 },
+    // Sinhala
+    { HB_MAKE_TAG('s', 'i', 'n', 'h'), 1 },
+    // Thai
+    { HB_MAKE_TAG('t', 'h', 'a', 'i'), 1 },
+    // Lao
+    { HB_MAKE_TAG('l', 'a', 'o', ' '), 1 },
+    // Tibetan
+    { HB_MAKE_TAG('t', 'i', 'b', 't'), 1 },
+    // Myanmar
+    { HB_MAKE_TAG('m', 'y', 'm', 'r'), 1 },
+    // Georgian
+    { HB_MAKE_TAG('g', 'e', 'o', 'r'), 0 },
+    // Hangul
+    { HB_MAKE_TAG('h', 'a', 'n', 'g'), 1 },
+    // Ogham
+    { HB_MAKE_TAG('o', 'g', 'a', 'm'), 0 },
+    // Runic
+    { HB_MAKE_TAG('r', 'u', 'n', 'r'), 0 },
+    // Khmer
+    { HB_MAKE_TAG('k', 'h', 'm', 'r'), 1 },
+    // N'Ko
+    { HB_MAKE_TAG('n', 'k', 'o', ' '), 1 }
+};
+enum { NumOTScripts = sizeof(ot_scripts)/sizeof(OTScripts) };
+
+static HB_Bool checkScript(HB_Face face, int script)
+{
+    assert(script < HB_ScriptCount);
+
+    if (!face->gsub && !face->gpos)
+        return false;
+
+    unsigned int tag = ot_scripts[script].tag;
+    int requirements = ot_scripts[script].flags;
+
+    if (requirements & RequiresGsub) {
+        if (!face->gsub)
+            return false;
+
+        HB_UShort script_index;
+        HB_Error error = HB_GSUB_Select_Script(face->gsub, tag, &script_index);
+        if (error) {
+            DEBUG("could not select script %d in GSub table: %d", (int)script, error);
+            error = HB_GSUB_Select_Script(face->gsub, HB_MAKE_TAG('D', 'F', 'L', 'T'), &script_index);
+            if (error)
+                return false;
+        }
+    }
+
+    if (requirements & RequiresGpos) {
+        if (!face->gpos)
+            return false;
+
+        HB_UShort script_index;
+        HB_Error error = HB_GPOS_Select_Script(face->gpos, script, &script_index);
+        if (error) {
+            DEBUG("could not select script in gpos table: %d", error);
+            error = HB_GPOS_Select_Script(face->gpos, HB_MAKE_TAG('D', 'F', 'L', 'T'), &script_index);
+            if (error)
+                return false;
+        }
+
+    }
+    return true;
+}
+
+static HB_Stream getTableStream(void *font, HB_GetFontTableFunc tableFunc, HB_Tag tag)
+{
+    HB_Error error;
+    HB_UInt length = 0;
+    HB_Stream stream = 0;
+
+    if (!font)
+        return 0;
+
+    error = tableFunc(font, tag, 0, &length);
+    if (error)
+        return 0;
+    stream = (HB_Stream)malloc(sizeof(HB_StreamRec));
+    if (!stream)
+        return 0;
+    stream->base = (HB_Byte*)malloc(length);
+    if (!stream->base) {
+        free(stream);
+        return 0;
+    }
+    error = tableFunc(font, tag, stream->base, &length);
+    if (error) {
+        _hb_close_stream(stream);
+        return 0;
+    }
+    stream->size = length;
+    stream->pos = 0;
+    stream->cursor = NULL;
+    return stream;
+}
+
+HB_Face HB_NewFace(void *font, HB_GetFontTableFunc tableFunc)
+{
+    HB_Face face = (HB_Face )malloc(sizeof(HB_FaceRec));
+    if (!face)
+        return 0;
+
+    face->isSymbolFont = false;
+    face->gdef = 0;
+    face->gpos = 0;
+    face->gsub = 0;
+    face->current_script = HB_ScriptCount;
+    face->current_flags = HB_ShaperFlag_Default;
+    face->has_opentype_kerning = false;
+    face->tmpAttributes = 0;
+    face->tmpLogClusters = 0;
+    face->glyphs_substituted = false;
+    face->buffer = 0;
+
+    HB_Error error = HB_Err_Ok;
+    HB_Stream stream;
+    HB_Stream gdefStream;
+
+    gdefStream = getTableStream(font, tableFunc, TTAG_GDEF);
+    error = HB_Err_Not_Covered;
+    if (!gdefStream || (error = HB_Load_GDEF_Table(gdefStream, &face->gdef))) {
+        //DEBUG("error loading gdef table: %d", error);
+        face->gdef = 0;
+    }
+
+    //DEBUG() << "trying to load gsub table";
+    stream = getTableStream(font, tableFunc, TTAG_GSUB);
+    error = HB_Err_Not_Covered;
+    if (!stream || (error = HB_Load_GSUB_Table(stream, &face->gsub, face->gdef, gdefStream))) {
+        face->gsub = 0;
+        if (error != HB_Err_Not_Covered) {
+            //DEBUG("error loading gsub table: %d", error);
+        } else {
+            //DEBUG("face doesn't have a gsub table");
+        }
+    }
+    _hb_close_stream(stream);
+
+    stream = getTableStream(font, tableFunc, TTAG_GPOS);
+    error = HB_Err_Not_Covered;
+    if (!stream || (error = HB_Load_GPOS_Table(stream, &face->gpos, face->gdef, gdefStream))) {
+        face->gpos = 0;
+        DEBUG("error loading gpos table: %d", error);
+    }
+    _hb_close_stream(stream);
+
+    _hb_close_stream(gdefStream);
+
+    for (unsigned int i = 0; i < HB_ScriptCount; ++i)
+        face->supported_scripts[i] = checkScript(face, i);
+
+    if (hb_buffer_new(&face->buffer) != HB_Err_Ok) {
+        HB_FreeFace(face);
+        return 0;
+    }
+
+    return face;
+}
+
+void HB_FreeFace(HB_Face face)
+{
+    if (!face)
+        return;
+    if (face->gpos)
+        HB_Done_GPOS_Table(face->gpos);
+    if (face->gsub)
+        HB_Done_GSUB_Table(face->gsub);
+    if (face->gdef)
+        HB_Done_GDEF_Table(face->gdef);
+    if (face->buffer)
+        hb_buffer_free(face->buffer);
+    if (face->tmpAttributes)
+        free(face->tmpAttributes);
+    if (face->tmpLogClusters)
+        free(face->tmpLogClusters);
+    free(face);
+}
+
+HB_Bool HB_SelectScript(HB_ShaperItem *shaper_item, const HB_OpenTypeFeature *features)
+{
+    HB_Script script = shaper_item->item.script;
+
+    HB_Face face = shaper_item->face;
+    if (face->current_script == script && face->current_flags == shaper_item->shaperFlags)
+        return shaper_item->face->supported_scripts[script] ? true : false;
+
+    face->current_script = script;
+    face->current_flags = shaper_item->shaperFlags;
+
+    if (!shaper_item->face->supported_scripts[script])
+        return false;
+
+    assert(script < HB_ScriptCount);
+    // find script in our list of supported scripts.
+    unsigned int tag = ot_scripts[script].tag;
+
+    if (face->gsub && features) {
+#ifdef OT_DEBUG
+        {
+            HB_FeatureList featurelist = face->gsub->FeatureList;
+            int numfeatures = featurelist.FeatureCount;
+            DEBUG("gsub table has %d features", numfeatures);
+            for (int i = 0; i < numfeatures; i++) {
+                HB_FeatureRecord *r = featurelist.FeatureRecord + i;
+                DEBUG("   feature '%s'", tag_to_string(r->FeatureTag));
+            }
+        }
+#endif
+        HB_GSUB_Clear_Features(face->gsub);
+        HB_UShort script_index;
+        HB_Error error = HB_GSUB_Select_Script(face->gsub, tag, &script_index);
+        if (!error) {
+            DEBUG("script %s has script index %d", tag_to_string(script), script_index);
+            while (features->tag) {
+                HB_UShort feature_index;
+                error = HB_GSUB_Select_Feature(face->gsub, features->tag, script_index, 0xffff, &feature_index);
+                if (!error) {
+                    DEBUG("  adding feature %s", tag_to_string(features->tag));
+                    HB_GSUB_Add_Feature(face->gsub, feature_index, features->property);
+                }
+                ++features;
+            }
+        }
+    }
+
+    // reset
+    face->has_opentype_kerning = false;
+
+    if (face->gpos) {
+        HB_GPOS_Clear_Features(face->gpos);
+        HB_UShort script_index;
+        HB_Error error = HB_GPOS_Select_Script(face->gpos, tag, &script_index);
+        if (!error) {
+#ifdef OT_DEBUG
+            {
+                HB_FeatureList featurelist = face->gpos->FeatureList;
+                int numfeatures = featurelist.FeatureCount;
+                DEBUG("gpos table has %d features", numfeatures);
+                for(int i = 0; i < numfeatures; i++) {
+                    HB_FeatureRecord *r = featurelist.FeatureRecord + i;
+                    HB_UShort feature_index;
+                    HB_GPOS_Select_Feature(face->gpos, r->FeatureTag, script_index, 0xffff, &feature_index);
+                    DEBUG("   feature '%s'", tag_to_string(r->FeatureTag));
+                }
+            }
+#endif
+            HB_UInt *feature_tag_list_buffer;
+            error = HB_GPOS_Query_Features(face->gpos, script_index, 0xffff, &feature_tag_list_buffer);
+            if (!error) {
+                HB_UInt *feature_tag_list = feature_tag_list_buffer;
+                while (*feature_tag_list) {
+                    HB_UShort feature_index;
+                    bool skip = false;
+                    if (*feature_tag_list == HB_MAKE_TAG('k', 'e', 'r', 'n')) {
+                        if (face->current_flags & HB_ShaperFlag_NoKerning)
+                            skip = true;
+                        else
+                            face->has_opentype_kerning = true;
+                    }
+                    features = disabled_features;
+                    while (features->tag) {
+                        if (*feature_tag_list == features->tag) {
+                            skip = true;
+                            break;
+                        }
+                        ++features;
+                    }
+                    // 'palt' should be turned off by default unless 'kern' is on
+                    if (!face->has_opentype_kerning &&
+                        *feature_tag_list == HB_MAKE_TAG('p', 'a', 'l', 't'))
+                        skip = true;
+
+                    if (skip) {
+                        ++feature_tag_list;
+                        continue;
+                    }
+                    error = HB_GPOS_Select_Feature(face->gpos, *feature_tag_list, script_index, 0xffff, &feature_index);
+                    if (!error)
+                        HB_GPOS_Add_Feature(face->gpos, feature_index, PositioningProperties);
+                    ++feature_tag_list;
+                }
+                FREE(feature_tag_list_buffer);
+            }
+        }
+    }
+
+    return true;
+}
+
+HB_Bool HB_OpenTypeShape(HB_ShaperItem *item, const hb_uint32 *properties)
+{
+    HB_GlyphAttributes *tmpAttributes;
+    unsigned int *tmpLogClusters;
+
+    HB_Face face = item->face;
+
+    face->length = item->num_glyphs;
+
+    hb_buffer_clear(face->buffer);
+
+    tmpAttributes = (HB_GlyphAttributes *) realloc(face->tmpAttributes, face->length*sizeof(HB_GlyphAttributes));
+    if (!tmpAttributes)
+        return false;
+    face->tmpAttributes = tmpAttributes;
+
+    tmpLogClusters = (unsigned int *) realloc(face->tmpLogClusters, face->length*sizeof(unsigned int));
+    if (!tmpLogClusters)
+        return false;
+    face->tmpLogClusters = tmpLogClusters;
+
+    for (int i = 0; i < face->length; ++i) {
+        hb_buffer_add_glyph(face->buffer, item->glyphs[i], properties ? properties[i] : 0, i);
+        face->tmpAttributes[i] = item->attributes[i];
+        face->tmpLogClusters[i] = item->log_clusters[i];
+    }
+
+#ifdef OT_DEBUG
+    DEBUG("-----------------------------------------");
+//     DEBUG("log clusters before shaping:");
+//     for (int j = 0; j < length; j++)
+//         DEBUG("    log[%d] = %d", j, item->log_clusters[j]);
+    DEBUG("original glyphs: %p", item->glyphs);
+    for (int i = 0; i < length; ++i)
+        DEBUG("   glyph=%4x", hb_buffer->in_string[i].gindex);
+//     dump_string(hb_buffer);
+#endif
+
+    face->glyphs_substituted = false;
+    if (face->gsub) {
+        unsigned int error = HB_GSUB_Apply_String(face->gsub, face->buffer);
+        if (error && error != HB_Err_Not_Covered)
+            return false;
+        face->glyphs_substituted = (error != HB_Err_Not_Covered);
+    }
+
+#ifdef OT_DEBUG
+//     DEBUG("log clusters before shaping:");
+//     for (int j = 0; j < length; j++)
+//         DEBUG("    log[%d] = %d", j, item->log_clusters[j]);
+    DEBUG("shaped glyphs:");
+    for (int i = 0; i < length; ++i)
+        DEBUG("   glyph=%4x", hb_buffer->in_string[i].gindex);
+    DEBUG("-----------------------------------------");
+//     dump_string(hb_buffer);
+#endif
+
+    return true;
+}
+
+HB_Bool HB_OpenTypePosition(HB_ShaperItem *item, int availableGlyphs, HB_Bool doLogClusters)
+{
+    HB_Face face = item->face;
+
+    bool glyphs_positioned = false;
+    if (face->gpos) {
+        if (face->buffer->positions)
+            memset(face->buffer->positions, 0, face->buffer->in_length*sizeof(HB_PositionRec));
+        // #### check that passing "false,false" is correct
+        glyphs_positioned = HB_GPOS_Apply_String(item->font, face->gpos, face->current_flags, face->buffer, false, false) != HB_Err_Not_Covered;
+    }
+
+    if (!face->glyphs_substituted && !glyphs_positioned) {
+        HB_HeuristicPosition(item);
+        return true; // nothing to do for us
+    }
+
+    // make sure we have enough space to write everything back
+    if (availableGlyphs < (int)face->buffer->in_length) {
+        item->num_glyphs = face->buffer->in_length;
+        return false;
+    }
+
+    HB_Glyph *glyphs = item->glyphs;
+    HB_GlyphAttributes *attributes = item->attributes;
+
+    for (unsigned int i = 0; i < face->buffer->in_length; ++i) {
+        glyphs[i] = face->buffer->in_string[i].gindex;
+        attributes[i] = face->tmpAttributes[face->buffer->in_string[i].cluster];
+        if (i && face->buffer->in_string[i].cluster == face->buffer->in_string[i-1].cluster)
+            attributes[i].clusterStart = false;
+    }
+    item->num_glyphs = face->buffer->in_length;
+
+    if (doLogClusters && face->glyphs_substituted) {
+        // we can't do this for indic, as we pass the stuf in syllables and it's easier to do it in the shaper.
+        unsigned short *logClusters = item->log_clusters;
+        int clusterStart = 0;
+        int oldCi = 0;
+        // #### the reconstruction of the logclusters currently does not work if the original string
+        // contains surrogate pairs
+        for (unsigned int i = 0; i < face->buffer->in_length; ++i) {
+            int ci = face->buffer->in_string[i].cluster;
+            //         DEBUG("   ci[%d] = %d mark=%d, cmb=%d, cs=%d",
+            //                i, ci, glyphAttributes[i].mark, glyphAttributes[i].combiningClass, glyphAttributes[i].clusterStart);
+            if (!attributes[i].mark && attributes[i].clusterStart && ci != oldCi) {
+                for (int j = oldCi; j < ci; j++)
+                    logClusters[j] = clusterStart;
+                clusterStart = i;
+                oldCi = ci;
+            }
+        }
+        for (int j = oldCi; j < face->length; j++)
+            logClusters[j] = clusterStart;
+    }
+
+    // calulate the advances for the shaped glyphs
+//     DEBUG("unpositioned: ");
+
+    // positioning code:
+    if (glyphs_positioned) {
+        HB_GetGlyphAdvances(item);
+        HB_Position positions = face->buffer->positions;
+        HB_Fixed *advances = item->advances;
+
+//         DEBUG("positioned glyphs:");
+        for (unsigned int i = 0; i < face->buffer->in_length; i++) {
+//             DEBUG("    %d:\t orig advance: (%d/%d)\tadv=(%d/%d)\tpos=(%d/%d)\tback=%d\tnew_advance=%d", i,
+//                    glyphs[i].advance.x.toInt(), glyphs[i].advance.y.toInt(),
+//                    (int)(positions[i].x_advance >> 6), (int)(positions[i].y_advance >> 6),
+//                    (int)(positions[i].x_pos >> 6), (int)(positions[i].y_pos >> 6),
+//                    positions[i].back, positions[i].new_advance);
+
+            HB_Fixed adjustment = (item->item.bidiLevel % 2) ? -positions[i].x_advance : positions[i].x_advance;
+
+            if (!(face->current_flags & HB_ShaperFlag_UseDesignMetrics))
+                adjustment = HB_FIXED_ROUND(adjustment);
+
+            if (positions[i].new_advance) {
+                advances[i] = adjustment;
+            } else {
+                advances[i] += adjustment;
+            }
+
+            int back = 0;
+            HB_FixedPoint *offsets = item->offsets;
+            offsets[i].x = positions[i].x_pos;
+            offsets[i].y = positions[i].y_pos;
+            while (positions[i - back].back) {
+                back += positions[i - back].back;
+                offsets[i].x += positions[i - back].x_pos;
+                offsets[i].y += positions[i - back].y_pos;
+            }
+            offsets[i].y = -offsets[i].y;
+
+            if (item->item.bidiLevel % 2) {
+                // ### may need to go back multiple glyphs like in ltr
+                back = positions[i].back;
+                while (back--)
+                    offsets[i].x -= advances[i-back];
+            } else {
+                back = 0;
+                while (positions[i - back].back) {
+                    back += positions[i - back].back;
+                    offsets[i].x -= advances[i-back];
+                }
+            }
+//             DEBUG("   ->\tadv=%d\tpos=(%d/%d)",
+//                    glyphs[i].advance.x.toInt(), glyphs[i].offset.x.toInt(), glyphs[i].offset.y.toInt());
+        }
+        item->kerning_applied = face->has_opentype_kerning;
+    } else {
+        HB_HeuristicPosition(item);
+    }
+
+#ifdef OT_DEBUG
+    if (doLogClusters) {
+        DEBUG("log clusters after shaping:");
+        for (int j = 0; j < length; j++)
+            DEBUG("    log[%d] = %d", j, item->log_clusters[j]);
+    }
+    DEBUG("final glyphs:");
+    for (int i = 0; i < (int)hb_buffer->in_length; ++i)
+        DEBUG("   glyph=%4x char_index=%d mark: %d cmp: %d, clusterStart: %d advance=%d/%d offset=%d/%d",
+               glyphs[i].glyph, hb_buffer->in_string[i].cluster, glyphs[i].attributes.mark,
+               glyphs[i].attributes.combiningClass, glyphs[i].attributes.clusterStart,
+               glyphs[i].advance.x.toInt(), glyphs[i].advance.y.toInt(),
+               glyphs[i].offset.x.toInt(), glyphs[i].offset.y.toInt());
+    DEBUG("-----------------------------------------");
+#endif
+    return true;
+}
+
+HB_Bool HB_ShapeItem(HB_ShaperItem *shaper_item)
+{
+    HB_Bool result = false;
+    if (shaper_item->num_glyphs < shaper_item->item.length) {
+        shaper_item->num_glyphs = shaper_item->item.length;
+        return false;
+    }
+    assert(shaper_item->item.script < HB_ScriptCount);
+    result = HB_ScriptEngines[shaper_item->item.script].shape(shaper_item);
+    shaper_item->glyphIndicesPresent = false;
+    return result;
+}
+