Exclude getHScale from DirectWrite font rendering

... and drop it, since it's unused now.
Unkike with Skia, where the ratio produces a visible effect, in
DirectWrite the effect seems cancelled by transformations. Yet,
it produced computational instability, noticable in small vertical
text.

Change-Id: I2f3b20913075d1338dc75c5a04c9cc0ef29c75ce
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/165877
Tested-by: Jenkins
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>

4 files changed, 18 insertions, 35 deletions

diff --git a/vcl/inc/win/DWriteTextRenderer.hxx b/vcl/inc/win/DWriteTextRenderer.hxx
index d4bb45e5895b..b822a6bca488 100644
--- a/vcl/inc/win/DWriteTextRenderer.hxx
+++ b/vcl/inc/win/DWriteTextRenderer.hxx
@@ -71,19 +71,4 @@ private:
     D2DTextAntiAliasMode meTextAntiAliasMode;
 };
 
-/**
- * Sets and unsets the needed DirectWrite transform to support the font's horizontal scaling and
- * rotation.
- */
-class WinFontTransformGuard
-{
-public:
-    WinFontTransformGuard(ID2D1RenderTarget* pRenderTarget, float fHScale, const GenericSalLayout& rLayout, const D2D1_POINT_2F& rBaseline, bool bIsVertical);
-    ~WinFontTransformGuard();
-
-private:
-    ID2D1RenderTarget* mpRenderTarget;
-    D2D1::Matrix3x2F maTransform;
-};
-
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/vcl/inc/win/winlayout.hxx b/vcl/inc/win/winlayout.hxx
index cfb36e825b54..31066a7db28a 100644
--- a/vcl/inc/win/winlayout.hxx
+++ b/vcl/inc/win/winlayout.hxx
@@ -36,8 +36,6 @@ class WinFontInstance : public LogicalFontInstance
 public:
     ~WinFontInstance() override;
 
-    float getHScale() const;
-
     void SetGraphics(WinSalGraphics*);
     WinSalGraphics* GetGraphics() const { return m_pGraphics; }
 
diff --git a/vcl/win/gdi/DWriteTextRenderer.cxx b/vcl/win/gdi/DWriteTextRenderer.cxx
index bb0f7e6b7661..633dcf82b13b 100644
--- a/vcl/win/gdi/DWriteTextRenderer.cxx
+++ b/vcl/win/gdi/DWriteTextRenderer.cxx
@@ -93,6 +93,20 @@ HRESULT checkResult(HRESULT hr, const char* location)
 #endif
 
 
+// Sets and unsets the needed DirectWrite transform to support the font's rotation.
+class WinFontTransformGuard
+{
+public:
+    WinFontTransformGuard(ID2D1RenderTarget* pRenderTarget,
+                          const GenericSalLayout& rLayout, const D2D1_POINT_2F& rBaseline,
+                          bool bIsVertical);
+    ~WinFontTransformGuard();
+
+private:
+    ID2D1RenderTarget* mpRenderTarget;
+    D2D1::Matrix3x2F maTransform;
+};
+
 } // end anonymous namespace
 
 D2DWriteTextOutRenderer::D2DWriteTextOutRenderer(bool bRenderingModeNatural)
@@ -214,7 +228,6 @@ bool D2DWriteTextOutRenderer::performRender(GenericSalLayout const & rLayout, Sa
     }
 
     const WinFontInstance& rWinFont = static_cast<const WinFontInstance&>(rLayout.GetFont());
-    float fHScale = rWinFont.getHScale();
 
     float lfEmHeight = 0;
     IDWriteFontFace* pFontFace = GetDWriteFace(rWinFont, &lfEmHeight);
@@ -247,11 +260,11 @@ bool D2DWriteTextOutRenderer::performRender(GenericSalLayout const & rLayout, Sa
         while (rLayout.GetNextGlyph(&pGlyph, aPos, nStart))
         {
             UINT16 glyphIndices[] = { static_cast<UINT16>(pGlyph->glyphId()) };
-            FLOAT glyphAdvances[] = { static_cast<FLOAT>(pGlyph->newWidth()) / fHScale };
+            FLOAT glyphAdvances[] = { static_cast<FLOAT>(pGlyph->newWidth()) };
             DWRITE_GLYPH_OFFSET glyphOffsets[] = { { 0.0f, 0.0f }, };
-            D2D1_POINT_2F baseline = { static_cast<FLOAT>(aPos.getX() - bounds.Left()) / fHScale,
+            D2D1_POINT_2F baseline = { static_cast<FLOAT>(aPos.getX() - bounds.Left()),
                                        static_cast<FLOAT>(aPos.getY() - bounds.Top()) };
-            WinFontTransformGuard aTransformGuard(mpRT, fHScale, rLayout, baseline, pGlyph->IsVertical());
+            WinFontTransformGuard aTransformGuard(mpRT, rLayout, baseline, pGlyph->IsVertical());
             DWRITE_GLYPH_RUN glyphs = {
                 pFontFace,
                 lfEmHeight,
@@ -302,7 +315,7 @@ IDWriteFontFace* D2DWriteTextOutRenderer::GetDWriteFace(const WinFontInstance& r
     return pFontFace;
 }
 
-WinFontTransformGuard::WinFontTransformGuard(ID2D1RenderTarget* pRenderTarget, float fHScale,
+WinFontTransformGuard::WinFontTransformGuard(ID2D1RenderTarget* pRenderTarget,
                                              const GenericSalLayout& rLayout,
                                              const D2D1_POINT_2F& rBaseline,
                                              bool bIsVertical)
@@ -310,11 +323,6 @@ WinFontTransformGuard::WinFontTransformGuard(ID2D1RenderTarget* pRenderTarget, f
 {
     pRenderTarget->GetTransform(&maTransform);
     D2D1::Matrix3x2F aTransform = maTransform;
-    if (fHScale != 1.0f)
-    {
-        aTransform
-            = aTransform * D2D1::Matrix3x2F::Scale(D2D1::Size(fHScale, 1.0f), D2D1::Point2F(0, 0));
-    }
 
     Degree10 angle = rLayout.GetOrientation();
 
diff --git a/vcl/win/gdi/winlayout.cxx b/vcl/win/gdi/winlayout.cxx
index 19eaae2ecee7..0c64759e1ab8 100644
--- a/vcl/win/gdi/winlayout.cxx
+++ b/vcl/win/gdi/winlayout.cxx
@@ -146,14 +146,6 @@ WinFontInstance::~WinFontInstance()
         ::DeleteFont(m_hFont);
 }
 
-float WinFontInstance::getHScale() const
-{
-    const vcl::font::FontSelectPattern& rPattern = GetFontSelectPattern();
-    if (!rPattern.mnHeight || !rPattern.mnWidth)
-        return 1.0;
-    return rPattern.mnWidth * GetAverageWidthFactor() / rPattern.mnHeight;
-}
-
 void WinFontInstance::ImplInitHbFont(hb_font_t* /*pHbFont*/)
 {
     assert(m_pGraphics);