tdf#119302 WIN better font scale handling

Moves the scale factor into the LogicalFontInstance and uses the
Glyphs font fallback level to use the correct font and scale.

Probably the glyphs should be using a rtl::Reference to the
LogcalFontInstance instead of the fallback level. I don't know if
glyphs are evicted from the cache, if the fallback changes. There
is now an assert and all places will use 1.0 as the default
scaling factor, so LO should at least not crash.

Reviewed-on: https://gerrit.libreoffice.org/60091
Tested-by: Jenkins
Reviewed-by: Jan-Marek Glogowski <glogow@fbihome.de>
(cherry picked from commit c177c305fc839e7a64d228ec56209d133588572b)

Conflicts:
	vcl/inc/win/salgdi.h
	vcl/win/gdi/salfont.cxx

Change-Id: I9dd4fc3a5b5924fc379b48a7f71c9eed26b4779d
Reviewed-on: https://gerrit.libreoffice.org/60722
Reviewed-by: Michael Stahl <Michael.Stahl@cib.de>
Tested-by: Thorsten Behrens <Thorsten.Behrens@CIB.de>

4 files changed, 46 insertions, 25 deletions

diff --git a/vcl/inc/win/salgdi.h b/vcl/inc/win/salgdi.h
index fe4f4b8dc8eb..d43a1b28bef7 100644
--- a/vcl/inc/win/salgdi.h
+++ b/vcl/inc/win/salgdi.h
@@ -172,7 +172,6 @@ private:
     HFONT                   mhFonts[ MAX_FALLBACK ];        // Font + Fallbacks
     WinFontInstance*       mpWinFontEntry[ MAX_FALLBACK ]; // pointer to the most recent font instance
     float                   mfFontScale[ MAX_FALLBACK ];        // allows metrics emulation of huge font sizes
-    float                   mfCurrentFontScale;
     HRGN                    mhRegion;           // vcl::Region Handle
     HPEN                    mhDefPen;           // DefaultPen
     HBRUSH                  mhDefBrush;         // DefaultBrush
diff --git a/vcl/inc/win/winlayout.hxx b/vcl/inc/win/winlayout.hxx
index 2e22834c891e..0c447153c800 100644
--- a/vcl/inc/win/winlayout.hxx
+++ b/vcl/inc/win/winlayout.hxx
@@ -156,6 +156,8 @@ public:
 
     void SetHFONT(const HFONT);
     HFONT GetHFONT() const { return m_hFont; }
+    void SetScale(float fScale) { m_fScale = fScale; }
+    float GetScale() const { return m_fScale; }
 
     // Prevend deletion of the HFONT in the WinFontInstance destructor
     // Used for the ScopedFont handling
@@ -167,6 +169,7 @@ private:
     virtual hb_font_t* ImplInitHbFont() override;
 
     HFONT m_hFont;
+    float m_fScale;
     GlyphCache maGlyphCache;
 };
 
diff --git a/vcl/win/gdi/salfont.cxx b/vcl/win/gdi/salfont.cxx
index 81c8d3a92628..8056b46522a6 100644
--- a/vcl/win/gdi/salfont.cxx
+++ b/vcl/win/gdi/salfont.cxx
@@ -925,7 +925,6 @@ void WinSalGraphics::SetFont( const FontSelectPattern* pFont, int nFallbackLevel
             ::SelectFont(getHDC(), mhDefFont);
             mhDefFont = nullptr;
         }
-        mfCurrentFontScale = mfFontScale[nFallbackLevel];
         // release no longer referenced font handles
         for( int i = nFallbackLevel; i < MAX_FALLBACK; ++i )
         {
@@ -939,6 +938,7 @@ void WinSalGraphics::SetFont( const FontSelectPattern* pFont, int nFallbackLevel
                 GetWinFontEntry(i)->Release();
                 mpWinFontEntry[i] = nullptr;
             }
+            mfFontScale[i] = 1.0;
         }
         return;
     }
@@ -953,52 +953,61 @@ void WinSalGraphics::SetFont( const FontSelectPattern* pFont, int nFallbackLevel
     {
         pFont->mpFontInstance->Acquire();
     }
-    mpWinFontEntry[ nFallbackLevel ] = reinterpret_cast<WinFontInstance*>( pFont->mpFontInstance );
+
+    WinFontInstance *pFontInstance = static_cast<WinFontInstance*>(pFont->mpFontInstance);
+    mpWinFontEntry[ nFallbackLevel ] = pFontInstance;
 
     HFONT hOldFont = nullptr;
-    HFONT hNewFont = mpWinFontEntry[ nFallbackLevel ] ? mpWinFontEntry[ nFallbackLevel ]->GetHFONT() : nullptr;
+    HFONT hNewFont = pFontInstance ? pFontInstance->GetHFONT() : nullptr;
     if (!hNewFont)
     {
-        hNewFont = ImplDoSetFont(pFont->GetFontSelectPattern(), pFont->GetFontFace(), mfFontScale[ nFallbackLevel ], hOldFont);
-        mpWinFontEntry[ nFallbackLevel ]->SetHFONT(hNewFont);
+        float fFontScale = 1.0;
+        hNewFont = ImplDoSetFont(pFont, nullptr, fFontScale, hOldFont);
+        if (pFontInstance)
+        {
+            pFontInstance->SetHFONT(hNewFont);
+            pFontInstance->SetScale(fFontScale);
+        }
+        else
+        {
+            if (mhFonts[nFallbackLevel])
+                ::DeleteFont(mhFonts[nFallbackLevel]);
+            mhFonts[nFallbackLevel] = hNewFont;
+            mfFontScale[nFallbackLevel] = fFontScale;
+        }
     }
     else
         hOldFont = ::SelectFont( getHDC(), hNewFont );
 
-    mfCurrentFontScale = mfFontScale[nFallbackLevel];
-
+    // keep default font
     if( !mhDefFont )
-    {
-        // keep default font
         mhDefFont = hOldFont;
-    }
     else
     {
         // release no longer referenced font handles
-        for( int i = nFallbackLevel; i < MAX_FALLBACK; ++i )
+        for (int i = nFallbackLevel + 1; i < MAX_FALLBACK; ++i)
         {
-            if( mhFonts[i] )
+            if (mhFonts[i])
             {
                 ::DeleteFont( mhFonts[i] );
                 mhFonts[i] = nullptr;
             }
-            if (i > nFallbackLevel && mpWinFontEntry[i])
+            if (mpWinFontEntry[i])
             {
                 GetWinFontEntry(i)->Release();
                 mpWinFontEntry[i] = nullptr;
             }
+            mfFontScale[i] = 1.0;
         }
     }
 
     // store new font in correct layer
-    if (mpWinFontEntry[nFallbackLevel])
+    if (pFontInstance)
     {
         // now the font is live => update font face
-        const WinFontFace* pFontFace = static_cast<const WinFontFace*>(mpWinFontEntry[nFallbackLevel]->GetFontFace());
+        const WinFontFace* pFontFace = static_cast<const WinFontFace*>(pFontInstance->GetFontFace());
         pFontFace->UpdateFromHDC(getHDC());
     }
-    else
-        mhFonts[ nFallbackLevel ] = hNewFont;
 }
 
 void WinSalGraphics::GetFontMetric( ImplFontMetricDataRef& rxFontMetric, int nFallbackLevel )
@@ -1037,7 +1046,7 @@ void WinSalGraphics::GetFontMetric( ImplFontMetricDataRef& rxFontMetric, int nFa
     rxFontMetric->SetSlant( 0 );
 
     // transformation dependent font metrics
-    rxFontMetric->SetWidth(static_cast<int>( mfFontScale[nFallbackLevel] * aWinMetric.tmAveCharWidth ));
+    rxFontMetric->SetWidth(static_cast<int>(mpWinFontEntry[nFallbackLevel]->GetScale() * 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());
@@ -1385,7 +1394,14 @@ bool WinSalGraphics::GetGlyphBoundRect(const GlyphItem& rGlyph, tools::Rectangle
         return true;
     }
 
+    WinFontInstance* pFont = mpWinFontEntry[rGlyph.mnFallbackLevel];
+    HFONT hNewFont = pFont ? pFont->GetHFONT() : mhFonts[rGlyph.mnFallbackLevel];
+    float fFontScale = pFont ? pFont->GetScale() : mfFontScale[rGlyph.mnFallbackLevel];
+
     HDC hDC = getHDC();
+    HFONT hFont = static_cast<HFONT>(GetCurrentObject(hDC, OBJ_FONT));
+    if (hNewFont && (hFont != hNewFont))
+        SelectObject(hDC, hNewFont);
 
     // use unity matrix
     MAT2 aMat;
@@ -1399,15 +1415,17 @@ bool WinSalGraphics::GetGlyphBoundRect(const GlyphItem& rGlyph, tools::Rectangle
     aGM.gmptGlyphOrigin.x = aGM.gmptGlyphOrigin.y = 0;
     aGM.gmBlackBoxX = aGM.gmBlackBoxY = 0;
     DWORD nSize = ::GetGlyphOutlineW(hDC, rGlyph.maGlyphId, nGGOFlags, &aGM, 0, nullptr, &aMat);
+    if (hNewFont && (hFont != hNewFont))
+        SelectObject(hDC, hFont);
     if( nSize == GDI_ERROR )
         return false;
 
     rRect = tools::Rectangle( Point( +aGM.gmptGlyphOrigin.x, -aGM.gmptGlyphOrigin.y ),
         Size( aGM.gmBlackBoxX, aGM.gmBlackBoxY ) );
-    rRect.SetLeft(static_cast<int>( mfCurrentFontScale * rRect.Left() ));
-    rRect.SetRight(static_cast<int>( mfCurrentFontScale * rRect.Right() ) + 1);
-    rRect.SetTop(static_cast<int>( mfCurrentFontScale * rRect.Top() ));
-    rRect.SetBottom(static_cast<int>( mfCurrentFontScale * rRect.Bottom() ) + 1);
+    rRect.SetLeft(static_cast<int>( fFontScale * rRect.Left() ));
+    rRect.SetRight(static_cast<int>( fFontScale * rRect.Right() ) + 1);
+    rRect.SetTop(static_cast<int>( fFontScale * rRect.Top() ));
+    rRect.SetBottom(static_cast<int>( fFontScale * rRect.Bottom() ) + 1);
 
     g_BoundRectCache.insert({rGlyph.maGlyphId, rRect});
 
@@ -1587,7 +1605,9 @@ bool WinSalGraphics::GetGlyphOutline(const GlyphItem& rGlyph,
     // rescaling needed for the tools::PolyPolygon conversion
     if( rB2DPolyPoly.count() )
     {
-        const double fFactor(mfCurrentFontScale/256);
+        WinFontInstance *pFont = mpWinFontEntry[rGlyph.mnFallbackLevel];
+        float fFontScale = pFont ? pFont->GetScale() : mfFontScale[rGlyph.mnFallbackLevel];
+        const double fFactor(fFontScale/256);
         rB2DPolyPoly.transform(basegfx::utils::createScaleB2DHomMatrix(fFactor, fFactor));
     }
 
diff --git a/vcl/win/gdi/salgdi.cxx b/vcl/win/gdi/salgdi.cxx
index d38337b6d546..aba0d6e6589e 100644
--- a/vcl/win/gdi/salgdi.cxx
+++ b/vcl/win/gdi/salgdi.cxx
@@ -607,7 +607,6 @@ WinSalGraphics::WinSalGraphics(WinSalGraphics::Type eType, bool bScreen, HWND hW
     mbWindow(eType == WinSalGraphics::WINDOW),
     mbScreen(bScreen),
     mhWnd(hWnd),
-    mfCurrentFontScale(1.0),
     mhRegion(nullptr),
     mhDefPen(nullptr),
     mhDefBrush(nullptr),