tdf#81144 Chinese full-width punctuation does not align properly

Ideographic fullstop and comma in most Chinese fonts are centered,
while those in Japanese fonts align closer to the left. Original
compression algorithm trimed right side of the punctuation, making
fullwidth fullstop or comma in Chinese font visually unbalanced.
In worst case, it crowds together with the followed compressed
punctuation.

This patch fix the situation in the folowing way
1) make compression less stronger.
2) Trim space according to glyph bearing to font height ratio.
3) fix a memory access violation issue

Change-Id: Icff215064e6c442fd36eac8e01b01fb6acb27594
Reviewed-on: https://gerrit.libreoffice.org/19517
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Norbert Thiebaud <nthiebaud@gmail.com>

1 files changed, 16 insertions, 8 deletions

diff --git a/sw/source/core/txtnode/fntcache.cxx b/sw/source/core/txtnode/fntcache.cxx
index 2f09296b023b..ea290e4e7f06 100644
--- a/sw/source/core/txtnode/fntcache.cxx
+++ b/sw/source/core/txtnode/fntcache.cxx
@@ -629,6 +629,12 @@ static bool lcl_IsMonoSpaceFont( const vcl::RenderContext& rOut )
     return nWidth1 == nWidth2;
 }
 
+static bool lcl_IsFullstopCentered( const vcl::RenderContext& rOut )
+{
+    const FontMetric aMetric( rOut.GetFontMetric() );
+    return aMetric.IsFullstopCentered() ;
+}
+
 /* This helper structure (SwForbidden) contains the already marked parts of the string
     to avoid double lines (e.g grammar + spell check error) */
 
@@ -1053,7 +1059,7 @@ void SwFntObj::DrawText( SwDrawTextInfo &rInf )
                         lcl_IsMonoSpaceFont( *(rInf.GetpOut()) ) )
                     {
                         pSI->Compress( pKernArray, rInf.GetIdx(), rInf.GetLen(),
-                            rInf.GetKanaComp(), (sal_uInt16)aFont.GetSize().Height(), &aTextOriginPos );
+                            rInf.GetKanaComp(), (sal_uInt16)aFont.GetSize().Height(), lcl_IsFullstopCentered( rInf.GetOut() ) , &aTextOriginPos );
                         bSpecialJust = true;
                     }
                     ///Asian Justification
@@ -1224,7 +1230,7 @@ void SwFntObj::DrawText( SwDrawTextInfo &rInf )
                 {
                     pSI->Compress( pKernArray, rInf.GetIdx(), rInf.GetLen(),
                                    rInf.GetKanaComp(),
-                                   (sal_uInt16)aFont.GetSize().Height(), &aTextOriginPos );
+                                   (sal_uInt16)aFont.GetSize().Height(), lcl_IsFullstopCentered( rInf.GetOut() ), &aTextOriginPos );
                     bSpecialJust = true;
                 }
 
@@ -1434,10 +1440,10 @@ void SwFntObj::DrawText( SwDrawTextInfo &rInf )
                 Point aTmpPos( aTextOriginPos );
                 pSI->Compress( pScrArray, rInf.GetIdx(), rInf.GetLen(),
                                rInf.GetKanaComp(),
-                               (sal_uInt16)aFont.GetSize().Height(), &aTmpPos );
+                               (sal_uInt16)aFont.GetSize().Height(), lcl_IsFullstopCentered( rInf.GetOut() ), &aTmpPos );
                 pSI->Compress( pKernArray, rInf.GetIdx(), rInf.GetLen(),
                                rInf.GetKanaComp(),
-                               (sal_uInt16)aFont.GetSize().Height(), &aTextOriginPos );
+                               (sal_uInt16)aFont.GetSize().Height(), lcl_IsFullstopCentered( rInf.GetOut() ), &aTextOriginPos );
             }
 
             // Asian Justification
@@ -1904,7 +1910,7 @@ Size SwFntObj::GetTextSize( SwDrawTextInfo& rInf )
         if( bCompress )
             rInf.SetKanaDiff( rInf.GetScriptInfo()->Compress( pKernArray,
                 rInf.GetIdx(), nLn, rInf.GetKanaComp(),
-                (sal_uInt16)aFont.GetSize().Height() ) );
+                (sal_uInt16)aFont.GetSize().Height() ,lcl_IsFullstopCentered( rInf.GetOut() ) ) );
         else
             rInf.SetKanaDiff( 0 );
 
@@ -1967,7 +1973,7 @@ Size SwFntObj::GetTextSize( SwDrawTextInfo& rInf )
                                         rInf.GetIdx(), nLn );
             rInf.SetKanaDiff( rInf.GetScriptInfo()->Compress( pKernArray,
                 rInf.GetIdx(), nLn, rInf.GetKanaComp(),
-                (sal_uInt16) aFont.GetSize().Height() ) );
+                (sal_uInt16) aFont.GetSize().Height() ,lcl_IsFullstopCentered( rInf.GetOut() ) ) );
             aTextSize.Width() = pKernArray[ nLn - 1 ];
             delete[] pKernArray;
         }
@@ -2027,7 +2033,8 @@ sal_Int32 SwFntObj::GetCrsrOfst( SwDrawTextInfo &rInf )
         {
             pSI->Compress( pKernArray, rInf.GetIdx(), rInf.GetLen(),
                            rInf.GetKanaComp(),
-                           (sal_uInt16) aFont.GetSize().Height() );
+                           (sal_uInt16) aFont.GetSize().Height(),
+                           lcl_IsFullstopCentered( rInf.GetOut() ) );
         }
 
         // Asian Justification
@@ -2466,7 +2473,8 @@ sal_Int32 SwFont::GetTextBreak( SwDrawTextInfo& rInf, long nTextWidth )
         rInf.GetOut().GetTextArray( rInf.GetText(), pKernArray,
                                     rInf.GetIdx(), nLn );
         if( rInf.GetScriptInfo()->Compress( pKernArray, rInf.GetIdx(), nLn,
-                            rInf.GetKanaComp(), (sal_uInt16)GetHeight( m_nActual ) ) )
+                            rInf.GetKanaComp(), (sal_uInt16)GetHeight( m_nActual ),
+                            lcl_IsFullstopCentered( rInf.GetOut() ) ) )
         {
             long nKernAdd = nKern;
             sal_Int32 nTmpBreak = nTextBreak2;