Fix left to right full justification

I was overloading ApplyDXArray() with a HarfBuzz specific implementation
because the GenericSalLayout one was screwing right to left kerning, but
it seems to have broken left to right full justifications. Since
mnXOffset was introduced a bit earlier to fix a similar issue, it can
now be used here as well to minimize the possible side effects.

Seems to work fine for both left to right and right to left text now,
but at least one of my Arabic tests is regressing, so might need some
tweaking.

Change-Id: I1239b0ec77a4978f981a480400a6d01cda18af79

vcl/generic/glyphs/gcach_layout.cxx

@@ -90,102 +90,6 @@ void ServerFontLayout::AdjustLayout( ImplLayoutArgs& rArgs )
     }
 }
 
-// apply adjustments to glyph advances, e.g. as a result of justification.
-void ServerFontLayout::ApplyDXArray(ImplLayoutArgs& rArgs)
-{
-    if (bUseHarfBuzz)
-    {
-        if (m_GlyphItems.empty())
-            return;
-
-        // determine cluster boundaries and x base offset
-        const int nCharCount = rArgs.mnEndCharPos - rArgs.mnMinCharPos;
-        int* pLogCluster = (int*)alloca(nCharCount * sizeof(int));
-        size_t i;
-        int n,p;
-        long nBasePointX = -1;
-        if (mnLayoutFlags & SAL_LAYOUT_FOR_FALLBACK)
-            nBasePointX = 0;
-        for (p = 0; p < nCharCount; ++p)
-            pLogCluster[p] = -1;
-
-        for (i = 0; i < m_GlyphItems.size(); ++i)
-        {
-            n = m_GlyphItems[i].mnCharPos - rArgs.mnMinCharPos;
-            if ((n < 0) || (nCharCount <= n))
-                continue;
-            if (pLogCluster[n] < 0)
-                pLogCluster[n] = i;
-            if (nBasePointX < 0)
-                nBasePointX = m_GlyphItems[i].maLinearPos.X();
-        }
-        // retarget unresolved pLogCluster[n] to a glyph inside the cluster
-        // TODO: better do it while the deleted-glyph markers are still there
-        for (n = 0; n < nCharCount; ++n)
-            if ((p = pLogCluster[0]) >= 0)
-                break;
-        if (n >= nCharCount)
-            return;
-        for (n = 0; n < nCharCount; ++n)
-        {
-            if (pLogCluster[n] < 0)
-                pLogCluster[n] = p;
-            else
-                p = pLogCluster[n];
-        }
-
-        // calculate adjusted cluster widths
-        sal_Int32* pNewGlyphWidths = (sal_Int32*)alloca(m_GlyphItems.size() * sizeof(sal_Int32));
-        for (i = 0; i < m_GlyphItems.size(); ++i)
-            pNewGlyphWidths[i] = 0;
-
-        bool bRTL;
-        for (int nCharPos = p = -1; rArgs.GetNextPos(&nCharPos, &bRTL); )
-        {
-            n = nCharPos - rArgs.mnMinCharPos;
-            if ((n < 0) || (nCharCount <= n))  continue;
-
-            if (pLogCluster[n] >= 0)
-                p = pLogCluster[n];
-            if (p >= 0)
-            {
-                long nDelta = rArgs.mpDXArray[n];
-                if(n > 0)
-                    nDelta -= rArgs.mpDXArray[n - 1];
-                pNewGlyphWidths[p] += nDelta * mnUnitsPerPixel;
-            }
-        }
-
-        // move cluster positions using the adjusted widths
-        long nDelta = 0;
-        for (i = 0; i < m_GlyphItems.size(); ++i)
-        {
-            if (m_GlyphItems[i].IsClusterStart())
-            {
-                // calculate original and adjusted cluster width
-                int nOldClusterWidth = m_GlyphItems[i].mnNewWidth;
-                int nNewClusterWidth = pNewGlyphWidths[i];
-                size_t j;
-                for (j = i; ++j < m_GlyphItems.size(); )
-                {
-                    if (m_GlyphItems[j].IsClusterStart())
-                        break;
-                    if (!m_GlyphItems[j].IsDiacritic()) // #i99367# ignore diacritics
-                        nOldClusterWidth += m_GlyphItems[j].mnNewWidth;
-                    nNewClusterWidth += pNewGlyphWidths[j];
-                }
-                nDelta += nNewClusterWidth - nOldClusterWidth;
-            }
-            m_GlyphItems[i].mnNewWidth = pNewGlyphWidths[i];
-            m_GlyphItems[i].maLinearPos.X() += nDelta;
-        }
-    }
-    else
-    {
-        GenericSalLayout::ApplyDXArray(rArgs);
-    }
-}
-
 // =======================================================================
 
 static bool lcl_CharIsJoiner(sal_Unicode cChar)

vcl/inc/generic/glyphcache.hxx

@@ -322,7 +322,6 @@ public:
                     ServerFontLayout( ServerFont& );
     virtual bool    LayoutText( ImplLayoutArgs& );
     virtual void    AdjustLayout( ImplLayoutArgs& );
-    virtual void    ApplyDXArray( ImplLayoutArgs& );
     virtual void    DrawText( SalGraphics& ) const;
     ServerFont&     GetServerFont() const   { return mrServerFont; }
 };

vcl/source/gdi/sallayout.cxx

@@ -1090,7 +1090,7 @@ void GenericSalLayout::ApplyDXArray( ImplLayoutArgs& rArgs )
         if( m_GlyphItems[i].IsClusterStart() )
         {
             // calculate original and adjusted cluster width
-            int nOldClusterWidth = m_GlyphItems[i].mnNewWidth;
+            int nOldClusterWidth = m_GlyphItems[i].mnNewWidth - m_GlyphItems[i].mnXOffset;
             int nNewClusterWidth = pNewGlyphWidths[i];
             size_t j;
             for( j = i; ++j < m_GlyphItems.size(); )
@@ -1098,7 +1098,7 @@ void GenericSalLayout::ApplyDXArray( ImplLayoutArgs& rArgs )
                 if( m_GlyphItems[j].IsClusterStart() )
                     break;
                 if( !m_GlyphItems[j].IsDiacritic() ) // #i99367# ignore diacritics
-                    nOldClusterWidth += m_GlyphItems[j].mnNewWidth;
+                    nOldClusterWidth += m_GlyphItems[j].mnNewWidth -  m_GlyphItems[j].mnXOffset;
                 nNewClusterWidth += pNewGlyphWidths[j];
             }
             const int nDiff = nNewClusterWidth - nOldClusterWidth;