tdf#106990 set cleartype setting / force to use GDI render mode

With this we read the system setting for cleartype and set it to
the render target we are using.

Additionally we set the GDI like rendering mode which forces that
the text is rendered similar as this was done with GDI.

Change-Id: If6fb72bc371accf50278c968c94e625aee3f0953
Reviewed-on: https://gerrit.libreoffice.org/39602
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Michael Meeks <michael.meeks@collabora.com>

2 files changed, 86 insertions, 3 deletions

diff --git a/vcl/inc/win/winlayout.hxx b/vcl/inc/win/winlayout.hxx
index 456d371b52b8..9d2a40eba5be 100644
--- a/vcl/inc/win/winlayout.hxx
+++ b/vcl/inc/win/winlayout.hxx
@@ -196,6 +196,13 @@ public:
         HDC hDC) override;
 };
 
+enum class D2DTextAntiAliasMode
+{
+    Default,
+    ClearType,
+    AntiAliased,
+};
+
 class D2DWriteTextOutRenderer : public TextOutRenderer
 {
     typedef HRESULT(WINAPI *pD2D1CreateFactory_t)(D2D1_FACTORY_TYPE,
@@ -238,6 +245,11 @@ public:
 
     bool Ready() const { return mpGdiInterop && mpRT; }
 
+    void applyTextAntiAliasMode();
+    void setTextAntiAliasMode(D2DTextAntiAliasMode eMode)
+    {
+        meTextAntiAliasMode = eMode;
+    }
 private:
     static void CleanupModules();
 
@@ -256,6 +268,8 @@ private:
     IDWriteFontFace * mpFontFace;
     float             mlfEmHeight;
     HDC               mhDC;
+    D2DTextAntiAliasMode meTextAntiAliasMode;
+    IDWriteRenderingParams* mpRenderingParameters;
 };
 
 #endif // INCLUDED_VCL_INC_WIN_WINLAYOUT_HXX
diff --git a/vcl/win/gdi/winlayout.cxx b/vcl/win/gdi/winlayout.cxx
index a510eba4d61a..e7257d38bacd 100644
--- a/vcl/win/gdi/winlayout.cxx
+++ b/vcl/win/gdi/winlayout.cxx
@@ -77,6 +77,8 @@ bool WinFontInstance::CacheGlyphToAtlas(HDC hDC, HFONT hFont, int nGlyphIndex, S
     if (!pTxt)
         return false;
 
+    pTxt->setTextAntiAliasMode(D2DTextAntiAliasMode::AntiAliased);
+
     if (!pTxt->BindFont(aHDC.get()))
     {
         SAL_WARN("vcl.gdi", "Binding of font failed. The font might not be supported by Direct Write.");
@@ -173,6 +175,7 @@ bool WinFontInstance::CacheGlyphToAtlas(HDC hDC, HFONT hFont, int nGlyphIndex, S
     };
 
     pRT->BeginDraw();
+    pTxt->applyTextAntiAliasMode();
     pRT->DrawGlyphRun(baseline, &glyphs, pBrush);
     HRESULT hResult = pRT->EndDraw();
 
@@ -315,6 +318,47 @@ bool ExTextOutRenderer::operator ()(CommonSalLayout const &rLayout,
 
     return true;
 }
+namespace
+{
+
+D2DTextAntiAliasMode lclGetSystemTextAntiAliasMode()
+{
+    D2DTextAntiAliasMode eMode = D2DTextAntiAliasMode::Default;
+
+    BOOL bFontSmoothing;
+    if (!SystemParametersInfo(SPI_GETFONTSMOOTHING, 0, &bFontSmoothing, 0))
+        return eMode;
+
+    if (bFontSmoothing)
+    {
+        UINT nType;
+        if (!SystemParametersInfo(SPI_GETFONTSMOOTHINGTYPE, 0, &nType, 0))
+            return eMode;
+
+        eMode = (nType == FE_FONTSMOOTHINGCLEARTYPE) ? D2DTextAntiAliasMode::ClearType
+                                                     : D2DTextAntiAliasMode::AntiAliased;
+    }
+
+    return eMode;
+}
+
+IDWriteRenderingParams* lclSetRenderingMode(IDWriteFactory* pDWriteFactory, DWRITE_RENDERING_MODE eRenderingMode)
+{
+    IDWriteRenderingParams* pDefaultParameters = nullptr;
+    pDWriteFactory->CreateRenderingParams(&pDefaultParameters);
+
+    IDWriteRenderingParams* pParameters = nullptr;
+    pDWriteFactory->CreateCustomRenderingParams(
+        pDefaultParameters->GetGamma(),
+        pDefaultParameters->GetEnhancedContrast(),
+        pDefaultParameters->GetClearTypeLevel(),
+        pDefaultParameters->GetPixelGeometry(),
+        eRenderingMode,
+        &pParameters);
+    return pParameters;
+}
+
+} // end anonymous namespace
 
 D2DWriteTextOutRenderer::D2DWriteTextOutRenderer()
     : mpD2DFactory(nullptr),
@@ -322,11 +366,12 @@ D2DWriteTextOutRenderer::D2DWriteTextOutRenderer()
     mpGdiInterop(nullptr),
     mpRT(nullptr),
     mRTProps(D2D1::RenderTargetProperties(D2D1_RENDER_TARGET_TYPE_DEFAULT,
-    D2D1::PixelFormat(DXGI_FORMAT_B8G8R8A8_UNORM, D2D1_ALPHA_MODE_PREMULTIPLIED),
-    0, 0)),
+                                          D2D1::PixelFormat(DXGI_FORMAT_B8G8R8A8_UNORM, D2D1_ALPHA_MODE_PREMULTIPLIED),
+                                          0, 0)),
     mpFontFace(nullptr),
     mlfEmHeight(0.0f),
-    mhDC(nullptr)
+    mhDC(nullptr),
+    meTextAntiAliasMode(D2DTextAntiAliasMode::Default)
 {
     HRESULT hr = S_OK;
     hr = D2D1CreateFactory(D2D1_FACTORY_TYPE_SINGLE_THREADED, __uuidof(ID2D1Factory), nullptr, reinterpret_cast<void **>(&mpD2DFactory));
@@ -336,6 +381,8 @@ D2DWriteTextOutRenderer::D2DWriteTextOutRenderer()
         hr = mpDWriteFactory->GetGdiInterop(&mpGdiInterop);
         hr = CreateRenderTarget();
     }
+    meTextAntiAliasMode = lclGetSystemTextAntiAliasMode();
+    mpRenderingParameters = lclSetRenderingMode(mpDWriteFactory, DWRITE_RENDERING_MODE_GDI_CLASSIC);
 }
 
 D2DWriteTextOutRenderer::~D2DWriteTextOutRenderer()
@@ -352,6 +399,27 @@ D2DWriteTextOutRenderer::~D2DWriteTextOutRenderer()
     CleanupModules();
 }
 
+void D2DWriteTextOutRenderer::applyTextAntiAliasMode()
+{
+    D2D1_TEXT_ANTIALIAS_MODE eMode = D2D1_TEXT_ANTIALIAS_MODE_DEFAULT;
+    switch (meTextAntiAliasMode)
+    {
+        case D2DTextAntiAliasMode::Default:
+            eMode = D2D1_TEXT_ANTIALIAS_MODE_ALIASED;
+            break;
+        case D2DTextAntiAliasMode::AntiAliased:
+            eMode = D2D1_TEXT_ANTIALIAS_MODE_GRAYSCALE;
+            break;
+        case D2DTextAntiAliasMode::ClearType:
+            eMode = D2D1_TEXT_ANTIALIAS_MODE_CLEARTYPE;
+            break;
+        default:
+            break;
+    }
+    mpRT->SetTextAntialiasMode(eMode);
+    mpRT->SetTextRenderingParams(mpRenderingParameters);
+}
+
 bool D2DWriteTextOutRenderer::operator ()(CommonSalLayout const &rLayout,
     SalGraphics &rGraphics,
     HDC hDC)
@@ -377,6 +445,7 @@ bool D2DWriteTextOutRenderer::operator ()(CommonSalLayout const &rLayout,
     if (succeeded)
     {
         mpRT->BeginDraw();
+        applyTextAntiAliasMode();
 
         int nStart = 0;
         Point aPos(0, 0);