tdf#104533: Fix font metrics for non-SFNT fonts

They can still be used with the old layout engine, so fallback to old
code when we encounter one of them. Not needed on master as the old
layout engine is gone there.

Change-Id: Ibe3e4772cb519843eeb44cfc7efd912ae9737b69
Reviewed-on: https://gerrit.libreoffice.org/32049
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Khaled Hosny <khaledhosny@eglug.org>

1 files changed, 42 insertions, 6 deletions

diff --git a/vcl/win/gdi/salfont.cxx b/vcl/win/gdi/salfont.cxx
index 10ec674c9f07..fd207a5db7bf 100644
--- a/vcl/win/gdi/salfont.cxx
+++ b/vcl/win/gdi/salfont.cxx
@@ -1252,14 +1252,17 @@ void WinSalGraphics::GetFontMetric( ImplFontMetricDataRef& rxFontMetric, int nFa
 
     // get the font metric
     OUTLINETEXTMETRICW aOutlineMetric;
-    const bool bOK = GetOutlineTextMetricsW(getHDC(), sizeof(OUTLINETEXTMETRICW), &aOutlineMetric);
+    TEXTMETRICW aWinMetric;
+    bool bOK = GetOutlineTextMetricsW(getHDC(), sizeof(OUTLINETEXTMETRICW), &aOutlineMetric);
+    if (bOK)
+        aWinMetric = aOutlineMetric.otmTextMetrics;
+    else
+        bOK = GetTextMetricsW(getHDC(), &aWinMetric);
     // restore the HDC to the font in the base level
     SelectFont( getHDC(), hOldFont );
     if( !bOK )
         return;
 
-    TEXTMETRICW aWinMetric = aOutlineMetric.otmTextMetrics;
-
     // device independent font attributes
     rxFontMetric->SetFamilyType(ImplFamilyToSal( aWinMetric.tmPitchAndFamily ));
     rxFontMetric->SetSymbolFlag(aWinMetric.tmCharSet == SYMBOL_CHARSET);
@@ -1290,9 +1293,42 @@ void WinSalGraphics::GetFontMetric( ImplFontMetricDataRef& rxFontMetric, int nFa
     // transformation dependent font metrics
     rxFontMetric->SetWidth( static_cast<int>( mfFontScale[nFallbackLevel] * aWinMetric.tmAveCharWidth ) );
 
-    const std::vector<uint8_t> rHhea(aHheaRawData.get(), aHheaRawData.get() + aHheaRawData.size());
-    const std::vector<uint8_t> rOS2(aOS2RawData.get(), aOS2RawData.get() + aOS2RawData.size());
-    rxFontMetric->ImplCalcLineSpacing(rHhea, rOS2, aOutlineMetric.otmEMSquare);
+    if (aHheaRawData.size() > 0 || aOS2RawData.size() > 0)
+    {
+        const std::vector<uint8_t> rHhea(aHheaRawData.get(), aHheaRawData.get() + aHheaRawData.size());
+        const std::vector<uint8_t> rOS2(aOS2RawData.get(), aOS2RawData.get() + aOS2RawData.size());
+        rxFontMetric->ImplCalcLineSpacing(rHhea, rOS2, aOutlineMetric.otmEMSquare);
+    }
+    else
+    {
+        // Falback to GDI code, can only happen with non-SFNT fonts
+        rxFontMetric->SetInternalLeading( static_cast<int>( mfFontScale[nFallbackLevel] * aWinMetric.tmInternalLeading ) );
+        rxFontMetric->SetExternalLeading( static_cast<int>( mfFontScale[nFallbackLevel] * aWinMetric.tmExternalLeading ) );
+        rxFontMetric->SetAscent( static_cast<int>( mfFontScale[nFallbackLevel] * aWinMetric.tmAscent ) );
+        rxFontMetric->SetDescent( static_cast<int>( mfFontScale[nFallbackLevel] * aWinMetric.tmDescent ) );
+        // #107888# improved metric compatibility for Asian fonts...
+        // TODO: assess workaround below for CWS >= extleading
+        // TODO: evaluate use of aWinMetric.sTypo* members for CJK
+        if( mpWinFontData[nFallbackLevel] && mpWinFontData[nFallbackLevel]->SupportsCJK() )
+        {
+            rxFontMetric->SetInternalLeading( rxFontMetric->GetInternalLeading() + rxFontMetric->GetExternalLeading() );
+
+            // #109280# The line height for Asian fonts is too small.
+            // Therefore we add half of the external leading to the
+            // ascent, the other half is added to the descent.
+            const long nHalfTmpExtLeading = rxFontMetric->GetExternalLeading() / 2;
+            const long nOtherHalfTmpExtLeading = rxFontMetric->GetExternalLeading() - nHalfTmpExtLeading;
+
+            // #110641# external leading for Asian fonts.
+            // The factor 0.3 has been confirmed with experiments.
+            long nCJKExtLeading = static_cast<long>(0.30 * (rxFontMetric->GetAscent() + rxFontMetric->GetDescent()));
+            nCJKExtLeading -= rxFontMetric->GetExternalLeading();
+            rxFontMetric->SetExternalLeading( (nCJKExtLeading > 0) ? nCJKExtLeading : 0 );
+
+            rxFontMetric->SetAscent( rxFontMetric->GetAscent() + nHalfTmpExtLeading );
+            rxFontMetric->SetDescent(  rxFontMetric->GetDescent() + nOtherHalfTmpExtLeading );
+        }
+    }
 
     rxFontMetric->SetMinKashida( GetMinKashidaWidth() );
 }