Don’t shrink text from fallback fonts

This code is bogus in multiple ways:
* It scales text based on ascent or descent, but this makes no sense
as those control line height and nothing else, if one is to scale two
different fonts to “fit” together, cap or x height would be more
appropriate. This results in some text being ridiculously shrunk.
* Not only that, but it is comparing apples to oranges; original font
ascent/descent with the bounding box of the fallback glyphs, which
results in different scale ratios depending on the shape of the glyphs
at hand, which leads to all sorts of funny and irregular text.
* Even worse, the PDF export is completely broken in this case; it uses
the scaled down glyph widths but the unscaled font size, resulting in
cramped unreadable text.

Change-Id: Iaa6117ecfdad8388887d9a03b538e7327544ad5e
Reviewed-on: https://gerrit.libreoffice.org/4293
Reviewed-by: Bosdonnat Cedric <cedric.bosdonnat@free.fr>
Tested-by: Bosdonnat Cedric <cedric.bosdonnat@free.fr>
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

1 files changed, 4 insertions, 68 deletions

diff --git a/vcl/source/gdi/outdev3.cxx b/vcl/source/gdi/outdev3.cxx
index 38f1f2543cf0..999f703ebf7c 100644
--- a/vcl/source/gdi/outdev3.cxx
+++ b/vcl/source/gdi/outdev3.cxx
@@ -5877,9 +5877,9 @@ SalLayout* OutputDevice::ImplLayout( const OUString& rOrigStr, sal_Int32 nMinInd
     return pSalLayout;
 }
 
-SalLayout* OutputDevice::getFallbackFontThatFits(ImplFontEntry &rFallbackFont,
+SalLayout* OutputDevice::getFallbackFont(ImplFontEntry &rFallbackFont,
     FontSelectPattern &rFontSelData, int nFallbackLevel,
-    ImplLayoutArgs& rLayoutArgs, const ImplFontMetricData& rOrigMetric) const
+    ImplLayoutArgs& rLayoutArgs) const
 {
     rFallbackFont.mnSetFontFlags = mpGraphics->SetFont( &rFontSelData, nFallbackLevel );
 
@@ -5896,68 +5896,8 @@ SalLayout* OutputDevice::getFallbackFontThatFits(ImplFontEntry &rFallbackFont,
         return NULL;
     }
 
-    Rectangle aBoundRect;
-    bool bHaveBounding = false;
-    Rectangle aRectangle;
-
     pFallback->AdjustLayout( rLayoutArgs );
 
-    // All we care about here is getting the vertical bounds of this text and
-    // make sure it will fit inside the available space
-    Point aPos;
-    for( int nStart = 0;;)
-    {
-        sal_GlyphId nLGlyph;
-        if( !pFallback->GetNextGlyphs( 1, &nLGlyph, aPos, nStart ) )
-            break;
-
-        sal_GlyphId nFontTag = nFallbackLevel << GF_FONTSHIFT;
-        nLGlyph |= nFontTag;
-
-        // get bounding rectangle of individual glyph
-        if( mpGraphics->GetGlyphBoundRect( nLGlyph, aRectangle ) )
-        {
-            // merge rectangle
-            aRectangle += aPos;
-            aBoundRect.Union( aRectangle );
-            bHaveBounding = true;
-        }
-    }
-
-    // Shrink it down if it won't fit
-    if (bHaveBounding)
-    {
-        long  nGlyphsAscent = -aBoundRect.Top();
-        float fScaleTop = nGlyphsAscent > rOrigMetric.mnAscent ?
-            rOrigMetric.mnAscent/(float)nGlyphsAscent : 1;
-        long  nGlyphsDescent = aBoundRect.Bottom();
-        float fScaleBottom = nGlyphsDescent > rOrigMetric.mnDescent ?
-            rOrigMetric.mnDescent/(float)nGlyphsDescent : 1;
-        float fScale = fScaleBottom < fScaleTop ? fScaleBottom : fScaleTop;
-        if (fScale < 1)
-        {
-            long nOrigHeight = rFontSelData.mnHeight;
-            long nNewHeight = static_cast<int>(static_cast<float>(rFontSelData.mnHeight) * fScale);
-
-            if (nNewHeight == nOrigHeight)
-                --nNewHeight;
-
-            pFallback->Release();
-
-            rFontSelData.mnHeight = nNewHeight;
-            rFallbackFont.mnSetFontFlags = mpGraphics->SetFont( &rFontSelData, nFallbackLevel );
-            rFontSelData.mnHeight = nOrigHeight;
-
-            rLayoutArgs.ResetPos();
-            pFallback = mpGraphics->GetTextLayout( rLayoutArgs, nFallbackLevel );
-            if (pFallback && !pFallback->LayoutText(rLayoutArgs))
-            {
-                pFallback->Release();
-                pFallback = NULL;
-            }
-            SAL_WARN_IF(!pFallback, "vcl.gdi", "we couldn't layout text with a smaller point size that worked with a bigger one");
-        }
-    }
     return pFallback;
 }
 
@@ -5980,10 +5920,6 @@ SalLayout* OutputDevice::ImplGlyphFallbackLayout( SalLayout* pSalLayout, ImplLay
 
     FontSelectPattern aFontSelData = mpFontEntry->maFontSelData;
 
-    ImplFontMetricData aOrigMetric( aFontSelData );
-    // TODO: use cached metric in fontentry
-    mpGraphics->GetFontMetric( &aOrigMetric );
-
     // when device specific font substitution may have been performed for
     // the originally selected font then make sure that a fallback to that
     // font is performed first
@@ -6018,8 +5954,8 @@ SalLayout* OutputDevice::ImplGlyphFallbackLayout( SalLayout* pSalLayout, ImplLay
         }
 
         // create and add glyph fallback layout to multilayout
-        SalLayout* pFallback = getFallbackFontThatFits(*pFallbackFont, aFontSelData,
-            nFallbackLevel, rLayoutArgs, aOrigMetric);
+        SalLayout* pFallback = getFallbackFont(*pFallbackFont, aFontSelData,
+            nFallbackLevel, rLayoutArgs);
         if (pFallback)
         {
             if( !pMultiSalLayout )