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.

Change-Id: I9dd4fc3a5b5924fc379b48a7f71c9eed26b4779d
Reviewed-on: https://gerrit.libreoffice.org/60091
Tested-by: Jenkins
Reviewed-by: Jan-Marek Glogowski <glogow@fbihome.de>

4 files changed, 33 insertions, 20 deletions

diff --git a/vcl/inc/win/salgdi.h b/vcl/inc/win/salgdi.h
index 51d14cb7ddda..32a104bef88e 100644
--- a/vcl/inc/win/salgdi.h
+++ b/vcl/inc/win/salgdi.h
@@ -171,8 +171,6 @@ private:
     HFONT                   mhFonts[ MAX_FALLBACK ];        // Font + Fallbacks
     rtl::Reference<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 598d90c60588..066f7b587f6d 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; }
 
     // Prevent 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 8c1a6651bbd5..bed9c7a22376 100644
--- a/vcl/win/gdi/salfont.cxx
+++ b/vcl/win/gdi/salfont.cxx
@@ -919,7 +919,6 @@ void WinSalGraphics::SetFont(LogicalFontInstance* 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 )
         {
@@ -933,25 +932,24 @@ void WinSalGraphics::SetFont(LogicalFontInstance* pFont, int nFallbackLevel)
         return;
     }
 
-    mpWinFontEntry[ nFallbackLevel ] = static_cast<WinFontInstance*>(pFont);
+    WinFontInstance *pFontInstance = static_cast<WinFontInstance*>(pFont);
+    mpWinFontEntry[ nFallbackLevel ] = pFontInstance;
 
     HFONT hOldFont = nullptr;
-    HFONT hNewFont = mpWinFontEntry[ nFallbackLevel ]->GetHFONT();
+    HFONT hNewFont = pFontInstance->GetHFONT();
     if (!hNewFont)
     {
-        hNewFont = ImplDoSetFont(pFont->GetFontSelectPattern(), pFont->GetFontFace(), mfFontScale[ nFallbackLevel ], hOldFont);
+        float fFontScale = 1.0;
+        hNewFont = ImplDoSetFont(pFont->GetFontSelectPattern(), pFont->GetFontFace(), fFontScale, hOldFont);
         mpWinFontEntry[ nFallbackLevel ]->SetHFONT(hNewFont);
+        mpWinFontEntry[ nFallbackLevel ]->SetScale(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
@@ -968,7 +966,7 @@ void WinSalGraphics::SetFont(LogicalFontInstance* pFont, int nFallbackLevel)
     }
 
     // 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());
 }
 
@@ -1008,7 +1006,7 @@ 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());
@@ -1361,7 +1359,18 @@ bool WinSalGraphics::GetGlyphBoundRect(const GlyphItem& rGlyph, tools::Rectangle
         return true;
     }
 
+    rtl::Reference<WinFontInstance> pFont = mpWinFontEntry[rGlyph.mnFallbackLevel];
+    assert(pFont.is());
+
     HDC hDC = getHDC();
+    HFONT hFont = static_cast<HFONT>(GetCurrentObject(hDC, OBJ_FONT));
+    float fFontScale = 1.0;
+    if (pFont.is())
+    {
+        if (hFont != pFont->GetHFONT())
+            SelectObject(hDC, pFont->GetHFONT());
+        fFontScale = pFont->GetScale();
+    }
 
     // use unity matrix
     MAT2 aMat;
@@ -1375,15 +1384,17 @@ 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 (pFont.is() && hFont != pFont->GetHFONT())
+        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});
 
@@ -1563,7 +1574,10 @@ bool WinSalGraphics::GetGlyphOutline(const GlyphItem& rGlyph,
     // rescaling needed for the tools::PolyPolygon conversion
     if( rB2DPolyPoly.count() )
     {
-        const double fFactor(mfCurrentFontScale/256);
+        rtl::Reference<WinFontInstance> pFont = mpWinFontEntry[rGlyph.mnFallbackLevel];
+        assert(pFont.is());
+        float fFontScale = pFont.is() ? pFont->GetScale() : 1.0;
+        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 78961ddaa8ba..46155bbef3dc 100644
--- a/vcl/win/gdi/salgdi.cxx
+++ b/vcl/win/gdi/salgdi.cxx
@@ -608,7 +608,6 @@ 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),
@@ -626,7 +625,6 @@ WinSalGraphics::WinSalGraphics(WinSalGraphics::Type eType, bool bScreen, HWND hW
     {
         mhFonts[ i ] = nullptr;
         mpWinFontEntry[ i ] = nullptr;
-        mfFontScale[ i ] = 1.0;
     }
 }