fix line width in DrawPolyLine() with matrix (tdf#132498)

For backends that do the object-to-device coordinates transformation
directly, it's necessary to also convert the size of line width.
But simply multiplying it with the matrix can also rotate the line
width "vector", making it e.g. negative. So don't use just the X
coordinate, use vector length for the transformation, which is ok.
In fact it doesn't even make sense to treat width as a vector, because
a width simply is not a vector (and for this reason it's also not
actually used).

Change-Id: I1241c9cb29155df105170d568a879ebc32b11a5f
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/93203
Reviewed-by: Tomaž Vajngerl <quikee@gmail.com>
Tested-by: Jenkins

33 files changed, 148 insertions, 130 deletions

diff --git a/vcl/CppunitTest_vcl_backend_test.mk b/vcl/CppunitTest_vcl_backend_test.mk
index f146cb6238fe..5a886224034a 100644
--- a/vcl/CppunitTest_vcl_backend_test.mk
+++ b/vcl/CppunitTest_vcl_backend_test.mk
@@ -14,6 +14,7 @@ $(eval $(call gb_CppunitTest_add_exception_objects,vcl_backend_test, \
 ))
 
 $(eval $(call gb_CppunitTest_use_libraries,vcl_backend_test, \
+	basegfx \
 	comphelper \
 	cppu \
 	cppuhelper \
diff --git a/vcl/headless/svpgdi.cxx b/vcl/headless/svpgdi.cxx
index b5649b093e31..fadf641fd290 100644
--- a/vcl/headless/svpgdi.cxx
+++ b/vcl/headless/svpgdi.cxx
@@ -1092,7 +1092,7 @@ void SvpSalGraphics::drawPolyLine(sal_uInt32 nPoints, const SalPoint* pPtAry)
         basegfx::B2DHomMatrix(),
         aPoly,
         0.0,
-        basegfx::B2DVector(1.0, 1.0),
+        1.0,
         nullptr, // MM01
         basegfx::B2DLineJoin::Miter,
         css::drawing::LineCap_BUTT,
@@ -1456,7 +1456,7 @@ bool SvpSalGraphics::drawPolyLine(
     const basegfx::B2DHomMatrix& rObjectToDevice,
     const basegfx::B2DPolygon& rPolyLine,
     double fTransparency,
-    const basegfx::B2DVector& rLineWidth,
+    double fLineWidth,
     const std::vector< double >* pStroke, // MM01
     basegfx::B2DLineJoin eLineJoin,
     css::drawing::LineCap eLineCap,
@@ -1488,7 +1488,7 @@ bool SvpSalGraphics::drawPolyLine(
             rObjectToDevice,
             rPolyLine,
             fTransparency,
-            rLineWidth,
+            fLineWidth,
             pStroke, // MM01
             eLineJoin,
             eLineCap,
@@ -1508,7 +1508,7 @@ bool SvpSalGraphics::drawPolyLine(
     const basegfx::B2DHomMatrix& rObjectToDevice,
     const basegfx::B2DPolygon& rPolyLine,
     double fTransparency,
-    const basegfx::B2DVector& rLineWidth,
+    double fLineWidth,
     const std::vector< double >* pStroke, // MM01
     basegfx::B2DLineJoin eLineJoin,
     css::drawing::LineCap eLineCap,
@@ -1522,21 +1522,20 @@ bool SvpSalGraphics::drawPolyLine(
     }
 
     // need to check/handle LineWidth when ObjectToDevice transformation is used
-    basegfx::B2DVector aLineWidth(rLineWidth);
     const bool bObjectToDeviceIsIdentity(rObjectToDevice.isIdentity());
 
     // tdf#124848 calculate-back logical LineWidth for a hairline
     // since this implementation hands over the transformation to
     // the graphic sub-system
-    if(aLineWidth.equalZero())
+    if(fLineWidth == 0)
     {
-        aLineWidth = basegfx::B2DVector(1.0, 1.0);
+        fLineWidth = 1.0;
 
         if(!bObjectToDeviceIsIdentity)
         {
             basegfx::B2DHomMatrix aObjectToDeviceInv(rObjectToDevice);
             aObjectToDeviceInv.invert();
-            aLineWidth = aObjectToDeviceInv * aLineWidth;
+            fLineWidth = (aObjectToDeviceInv * basegfx::B2DVector(fLineWidth, 0)).getLength();
         }
     }
 
@@ -1617,7 +1616,7 @@ bool SvpSalGraphics::drawPolyLine(
 
     cairo_set_line_join(cr, eCairoLineJoin);
     cairo_set_line_cap(cr, eCairoLineCap);
-    cairo_set_line_width(cr, aLineWidth.getX());
+    cairo_set_line_width(cr, fLineWidth);
     cairo_set_miter_limit(cr, fMiterLimit);
 
     // try to access buffered data
@@ -1654,7 +1653,7 @@ bool SvpSalGraphics::drawPolyLine(
 
     // check for basegfx::B2DLineJoin::NONE to react accordingly
     const bool bNoJoin((basegfx::B2DLineJoin::NONE == eLineJoin
-        && basegfx::fTools::more(aLineWidth.getX(), 0.0)));
+        && basegfx::fTools::more(fLineWidth, 0.0)));
 
     if(pSystemDependentData_CairoPath)
     {
diff --git a/vcl/inc/headless/svpgdi.hxx b/vcl/inc/headless/svpgdi.hxx
index 99300ed03a53..3d1617d07100 100644
--- a/vcl/inc/headless/svpgdi.hxx
+++ b/vcl/inc/headless/svpgdi.hxx
@@ -113,7 +113,7 @@ public:
         const basegfx::B2DHomMatrix& rObjectToDevice,
         const basegfx::B2DPolygon& rPolyLine,
         double fTransparency,
-        const basegfx::B2DVector& rLineWidths,
+        double fLineWidth,
         const std::vector< double >* pStroke, // MM01
         basegfx::B2DLineJoin eLineJoin,
         css::drawing::LineCap eLineCap,
@@ -211,7 +211,7 @@ public:
                                 const basegfx::B2DHomMatrix& rObjectToDevice,
                                 const basegfx::B2DPolygon&,
                                 double fTransparency,
-                                const basegfx::B2DVector& rLineWidths,
+                                double fLineWidth,
                                 const std::vector< double >* pStroke, // MM01
                                 basegfx::B2DLineJoin,
                                 css::drawing::LineCap,
diff --git a/vcl/inc/opengl/RenderList.hxx b/vcl/inc/opengl/RenderList.hxx
index 06dd03b4d7d1..213a2f43b554 100644
--- a/vcl/inc/opengl/RenderList.hxx
+++ b/vcl/inc/opengl/RenderList.hxx
@@ -163,7 +163,7 @@ public:
                             Color nLineColor, Color nFillColor, bool bUseAA);
 
     void addDrawPolyLine(const basegfx::B2DPolygon& rPolygon, double fTransparency,
-                         const basegfx::B2DVector& rLineWidth, basegfx::B2DLineJoin eLineJoin,
+                         double fLineWidth, basegfx::B2DLineJoin eLineJoin,
                          css::drawing::LineCap eLineCap, double fMiterMinimumAngle,
                          Color nLineColor, bool bUseAA);
 };
diff --git a/vcl/inc/opengl/gdiimpl.hxx b/vcl/inc/opengl/gdiimpl.hxx
index ac488a28116e..a6de106a6018 100644
--- a/vcl/inc/opengl/gdiimpl.hxx
+++ b/vcl/inc/opengl/gdiimpl.hxx
@@ -259,7 +259,7 @@ public:
                 const basegfx::B2DHomMatrix& rObjectToDevice,
                 const basegfx::B2DPolygon&,
                 double fTransparency,
-                const basegfx::B2DVector& rLineWidths,
+                double fLineWidth,
                 const std::vector< double >* pStroke, // MM01
                 basegfx::B2DLineJoin,
                 css::drawing::LineCap,
diff --git a/vcl/inc/qt5/Qt5Graphics.hxx b/vcl/inc/qt5/Qt5Graphics.hxx
index 0a66271c34e5..bc4870ee7e18 100644
--- a/vcl/inc/qt5/Qt5Graphics.hxx
+++ b/vcl/inc/qt5/Qt5Graphics.hxx
@@ -118,8 +118,7 @@ public:
                                        const SalPoint* const* pPtAry,
                                        const PolyFlags* const* pFlgAry) override;
     virtual bool drawPolyLine(const basegfx::B2DHomMatrix& rObjectToDevice,
-                              const basegfx::B2DPolygon&, double fTransparency,
-                              const basegfx::B2DVector& rLineWidths,
+                              const basegfx::B2DPolygon&, double fTransparency, double fLineWidths,
                               const std::vector<double>* pStroke, // MM01
                               basegfx::B2DLineJoin, css::drawing::LineCap eLineCap,
                               double fMiterMinimumAngle, bool bPixelSnapHairline) override;
diff --git a/vcl/inc/quartz/salgdi.h b/vcl/inc/quartz/salgdi.h
index 3fa3a0e38e77..5e0222be05df 100644
--- a/vcl/inc/quartz/salgdi.h
+++ b/vcl/inc/quartz/salgdi.h
@@ -240,7 +240,7 @@ public:
                                 const basegfx::B2DHomMatrix& rObjectToDevice,
                                 const basegfx::B2DPolygon&,
                                 double fTransparency,
-                                const basegfx::B2DVector& rLineWidths,
+                                double rLineWidth,
                                 const std::vector< double >* pStroke, // MM01
                                 basegfx::B2DLineJoin,
                                 css::drawing::LineCap eLineCap,
diff --git a/vcl/inc/salgdi.hxx b/vcl/inc/salgdi.hxx
index 8ae88aba161a..2161ebeb6358 100644
--- a/vcl/inc/salgdi.hxx
+++ b/vcl/inc/salgdi.hxx
@@ -246,7 +246,7 @@ public:
                                     const basegfx::B2DHomMatrix& rObjectToDevice,
                                     const basegfx::B2DPolygon& i_rPolygon,
                                     double i_fTransparency,
-                                    const basegfx::B2DVector& i_rLineWidth,
+                                    double i_fLineWidth,
                                     const std::vector< double >* i_pStroke, // MM01
                                     basegfx::B2DLineJoin i_eLineJoin,
                                     css::drawing::LineCap i_eLineCap,
@@ -466,7 +466,7 @@ protected:
                                     const basegfx::B2DHomMatrix& rObjectToDevice,
                                     const basegfx::B2DPolygon&,
                                     double fTransparency,
-                                    const basegfx::B2DVector& rLineWidths,
+                                    double fLineWidth,
                                     const std::vector< double >* pStroke, // MM01
                                     basegfx::B2DLineJoin,
                                     css::drawing::LineCap,
diff --git a/vcl/inc/salgdiimpl.hxx b/vcl/inc/salgdiimpl.hxx
index 3b179a7131ad..0e62669d654e 100644
--- a/vcl/inc/salgdiimpl.hxx
+++ b/vcl/inc/salgdiimpl.hxx
@@ -109,7 +109,7 @@ public:
                 const basegfx::B2DHomMatrix& rObjectToDevice,
                 const basegfx::B2DPolygon&,
                 double fTransparency,
-                const basegfx::B2DVector& rLineWidths,
+                double fLineWidth,
                 const std::vector< double >* pStroke, // MM01
                 basegfx::B2DLineJoin,
                 css::drawing::LineCap,
diff --git a/vcl/inc/skia/gdiimpl.hxx b/vcl/inc/skia/gdiimpl.hxx
index 68652cacc790..c78845fe6ffa 100644
--- a/vcl/inc/skia/gdiimpl.hxx
+++ b/vcl/inc/skia/gdiimpl.hxx
@@ -103,8 +103,7 @@ public:
                                  const basegfx::B2DPolyPolygon&, double fTransparency) override;
 
     virtual bool drawPolyLine(const basegfx::B2DHomMatrix& rObjectToDevice,
-                              const basegfx::B2DPolygon&, double fTransparency,
-                              const basegfx::B2DVector& rLineWidths,
+                              const basegfx::B2DPolygon&, double fTransparency, double fLineWidth,
                               const std::vector<double>* pStroke, // MM01
                               basegfx::B2DLineJoin, css::drawing::LineCap,
                               double fMiterMinimumAngle, bool bPixelSnapHairline) override;
diff --git a/vcl/inc/unx/genpspgraphics.h b/vcl/inc/unx/genpspgraphics.h
index 6dfca7548f4b..6e68c9695c98 100644
--- a/vcl/inc/unx/genpspgraphics.h
+++ b/vcl/inc/unx/genpspgraphics.h
@@ -131,7 +131,7 @@ public:
                                 const basegfx::B2DHomMatrix& rObjectToDevice,
                                 const basegfx::B2DPolygon&,
                                 double fTransparency,
-                                const basegfx::B2DVector& rLineWidths,
+                                double fLineWidth,
                                 const std::vector< double >* pStroke, // MM01
                                 basegfx::B2DLineJoin,
                                 css::drawing::LineCap,
diff --git a/vcl/inc/unx/salgdi.h b/vcl/inc/unx/salgdi.h
index 19abfa0b8133..4216b703c14e 100644
--- a/vcl/inc/unx/salgdi.h
+++ b/vcl/inc/unx/salgdi.h
@@ -169,7 +169,7 @@ public:
                                         const basegfx::B2DHomMatrix& rObjectToDevice,
                                         const basegfx::B2DPolygon&,
                                         double fTransparency,
-                                        const basegfx::B2DVector& rLineWidth,
+                                        double fLineWidth,
                                         const std::vector< double >* pStroke, // MM01
                                         basegfx::B2DLineJoin,
                                         css::drawing::LineCap,
diff --git a/vcl/inc/win/salgdi.h b/vcl/inc/win/salgdi.h
index c45611a6e36e..4d1029167a85 100644
--- a/vcl/inc/win/salgdi.h
+++ b/vcl/inc/win/salgdi.h
@@ -241,7 +241,7 @@ protected:
         const basegfx::B2DHomMatrix& rObjectToDevice,
         const basegfx::B2DPolygon&,
         double fTransparency,
-        const basegfx::B2DVector& rLineWidth,
+        double fLineWidth,
         const std::vector< double >* pStroke, // MM01
         basegfx::B2DLineJoin,
         css::drawing::LineCap,
diff --git a/vcl/opengl/RenderList.cxx b/vcl/opengl/RenderList.cxx
index 81817950d05a..4830f1040de9 100644
--- a/vcl/opengl/RenderList.cxx
+++ b/vcl/opengl/RenderList.cxx
@@ -372,7 +372,7 @@ void RenderList::addDrawTextureWithMaskColor(OpenGLTexture const & rTexture, Col
 }
 
 void RenderList::addDrawPolyLine(const basegfx::B2DPolygon& rPolygon, double fTransparency,
-                                 const basegfx::B2DVector& rLineWidth, basegfx::B2DLineJoin eLineJoin,
+                                 double fLineWidth, basegfx::B2DLineJoin eLineJoin,
                                  css::drawing::LineCap eLineCap, double fMiterMinimumAngle,
                                  Color nLineColor, bool bUseAA)
 {
@@ -383,8 +383,8 @@ void RenderList::addDrawPolyLine(const basegfx::B2DPolygon& rPolygon, double fTr
     if (fTransparency == 1.0)
         return;
 
-    const bool bIsHairline = (rLineWidth.getX() == rLineWidth.getY()) && (rLineWidth.getX() <= 1.2);
-    const float fLineWidth = bIsHairline ? 1.0f : rLineWidth.getX();
+    const bool bIsHairline = fLineWidth <= 1.2;
+    fLineWidth = bIsHairline ? 1.0f : fLineWidth;
 
     basegfx::B2DPolygon aPolygon(rPolygon);
     if (rPolygon.areControlPointsUsed())
diff --git a/vcl/opengl/gdiimpl.cxx b/vcl/opengl/gdiimpl.cxx
index 25cac157a56b..6c76154ea498 100644
--- a/vcl/opengl/gdiimpl.cxx
+++ b/vcl/opengl/gdiimpl.cxx
@@ -1560,7 +1560,7 @@ void OpenGLSalGraphicsImpl::drawPolyLine( sal_uInt32 nPoints, const SalPoint* pP
         basegfx::B2DHomMatrix(),
         aPoly,
         0.0,
-        basegfx::B2DVector(1.0, 1.0),
+        1.0,
         nullptr, // MM01
         basegfx::B2DLineJoin::Miter,
         css::drawing::LineCap_BUTT,
@@ -1638,7 +1638,7 @@ bool OpenGLSalGraphicsImpl::drawPolyLine(
     const basegfx::B2DHomMatrix& rObjectToDevice,
     const basegfx::B2DPolygon& rPolygon,
     double fTransparency,
-    const basegfx::B2DVector& rLineWidth,
+    double fLineWidth,
     const std::vector< double >* pStroke, // MM01
     basegfx::B2DLineJoin eLineJoin,
     css::drawing::LineCap eLineCap,
@@ -1680,10 +1680,10 @@ bool OpenGLSalGraphicsImpl::drawPolyLine(
     if(bPixelSnapHairline) { aPolyPolygonLine = basegfx::utils::snapPointsOfHorizontalOrVerticalEdges(aPolyPolygonLine); }
 
     // tdf#124848 get correct LineWidth in discrete coordinates,
-    // take hairline case into account
-    const basegfx::B2DVector aLineWidth(rLineWidth.equalZero()
-        ? basegfx::B2DVector(1.0, 1.0)
-        : rObjectToDevice * rLineWidth);
+    if(fLineWidth == 0) // hairline
+        fLineWidth = 1.0;
+    else // Adjust line width for object-to-device scale.
+        fLineWidth = (rObjectToDevice * basegfx::B2DVector(fLineWidth, 0)).getLength();
 
     for(sal_uInt32 a(0); a < aPolyPolygonLine.count(); a++)
     {
@@ -1695,7 +1695,7 @@ bool OpenGLSalGraphicsImpl::drawPolyLine(
         mpRenderList->addDrawPolyLine(
             aPolyLine,
             fTransparency,
-            aLineWidth,
+            fLineWidth,
             eLineJoin,
             eLineCap,
             fMiterMinimumAngle,
diff --git a/vcl/qa/cppunit/BackendTest.cxx b/vcl/qa/cppunit/BackendTest.cxx
index 802e4eb239c6..f06d8fccb648 100644
--- a/vcl/qa/cppunit/BackendTest.cxx
+++ b/vcl/qa/cppunit/BackendTest.cxx
@@ -13,6 +13,7 @@
 #include <vcl/bitmap.hxx>
 #include <tools/stream.hxx>
 #include <vcl/graphicfilter.hxx>
+#include <basegfx/matrix/b2dhommatrix.hxx>
 
 #include <test/outputdevice.hxx>
 
@@ -44,6 +45,16 @@ class BackendTest : public test::BootstrapFixture
         }
     }
 
+    void exportDevice(const OUString& filename, const VclPtr<VirtualDevice>& device)
+    {
+        if (mbExportBitmap)
+        {
+            BitmapEx aBitmapEx(device->GetBitmap(Point(0, 0), device->GetOutputSizePixel()));
+            SvFileStream aStream(filename, StreamMode::WRITE | StreamMode::TRUNC);
+            GraphicFilter::GetGraphicFilter().compressAsPNG(aBitmapEx, aStream);
+        }
+    }
+
 public:
     BackendTest()
         : BootstrapFixture(true, false)
@@ -444,6 +455,36 @@ public:
             CPPUNIT_ASSERT(eResult != vcl::test::TestResult::Failed);
     }
 
+    void testTdf124848()
+    {
+        ScopedVclPtr<VirtualDevice> device = VclPtr<VirtualDevice>::Create(DeviceFormat::DEFAULT);
+        device->SetOutputSizePixel(Size(100, 100));
+        device->SetBackground(Wallpaper(COL_WHITE));
+        device->Erase();
+        device->SetAntialiasing(AntialiasingFlags::EnableB2dDraw);
+        device->SetLineColor(COL_BLACK);
+        basegfx::B2DHomMatrix matrix;
+        // DrawPolyLine() would apply the whole matrix to the line width, making it negative
+        // in case of a larger rotation.
+        matrix.rotate(M_PI); //180 degrees
+        matrix.translate(100, 100);
+        CPPUNIT_ASSERT(device->DrawPolyLineDirect(
+            matrix, basegfx::B2DPolygon{ { 50, 50 }, { 50, 100 } }, 100));
+        exportDevice("/tmp/tdf124848-1.png", device);
+        // 100px wide line should fill the entire width of the upper half
+        CPPUNIT_ASSERT_EQUAL(COL_BLACK, device->GetPixel(Point(2, 2)));
+
+        // Also check hairline.
+        device->Erase();
+        CPPUNIT_ASSERT(
+            device->DrawPolyLineDirect(matrix, basegfx::B2DPolygon{ { 50, 50 }, { 50, 100 } }, 0));
+        exportDevice("/tmp/tdf124848-2.png", device);
+        // 1px wide
+        CPPUNIT_ASSERT_EQUAL(COL_BLACK, device->GetPixel(Point(50, 20)));
+        CPPUNIT_ASSERT_EQUAL(COL_WHITE, device->GetPixel(Point(49, 20)));
+        CPPUNIT_ASSERT_EQUAL(COL_WHITE, device->GetPixel(Point(51, 20)));
+    }
+
     CPPUNIT_TEST_SUITE(BackendTest);
     CPPUNIT_TEST(testDrawRectWithRectangle);
     CPPUNIT_TEST(testDrawRectWithPixel);
@@ -487,6 +528,8 @@ public:
     CPPUNIT_TEST(testDrawBlend);
     CPPUNIT_TEST(testDrawXor);
 
+    CPPUNIT_TEST(testTdf124848);
+
     CPPUNIT_TEST_SUITE_END();
 };
 
diff --git a/vcl/qt5/Qt5Graphics_GDI.cxx b/vcl/qt5/Qt5Graphics_GDI.cxx
index eb43811466d4..cfebca7c6acb 100644
--- a/vcl/qt5/Qt5Graphics_GDI.cxx
+++ b/vcl/qt5/Qt5Graphics_GDI.cxx
@@ -325,7 +325,7 @@ bool Qt5Graphics::drawPolyPolygonBezier(sal_uInt32 /*nPoly*/, const sal_uInt32*
 
 bool Qt5Graphics::drawPolyLine(const basegfx::B2DHomMatrix& rObjectToDevice,
                                const basegfx::B2DPolygon& rPolyLine, double fTransparency,
-                               const basegfx::B2DVector& rLineWidth,
+                               double fLineWidth,
                                const std::vector<double>* pStroke, // MM01
                                basegfx::B2DLineJoin eLineJoin, css::drawing::LineCap eLineCap,
                                double fMiterMinimumAngle, bool bPixelSnapHairline)
@@ -371,9 +371,10 @@ bool Qt5Graphics::drawPolyLine(const basegfx::B2DHomMatrix& rObjectToDevice,
     }
 
     // tdf#124848 get correct LineWidth in discrete coordinates,
-    // take hairline case into account
-    const basegfx::B2DVector aLineWidth(rLineWidth.equalZero() ? basegfx::B2DVector(1.0, 1.0)
-                                                               : rObjectToDevice * rLineWidth);
+    if (fLineWidth == 0) // hairline
+        fLineWidth = 1.0;
+    else // Adjust line width for object-to-device scale.
+        fLineWidth = (rObjectToDevice * basegfx::B2DVector(fLineWidth, 0)).getLength();
 
     // setup poly-polygon path
     QPainterPath aPath;
@@ -390,7 +391,7 @@ bool Qt5Graphics::drawPolyLine(const basegfx::B2DHomMatrix& rObjectToDevice,
 
     // setup line attributes
     QPen aPen = aPainter.pen();
-    aPen.setWidth(aLineWidth.getX());
+    aPen.setWidth(fLineWidth);
 
     switch (eLineJoin)
     {
diff --git a/vcl/quartz/salgdicommon.cxx b/vcl/quartz/salgdicommon.cxx
index 51de3820f93d..3126400709f2 100644
--- a/vcl/quartz/salgdicommon.cxx
+++ b/vcl/quartz/salgdicommon.cxx
@@ -817,7 +817,7 @@ bool AquaSalGraphics::drawPolyLine(
     const basegfx::B2DHomMatrix& rObjectToDevice,
     const basegfx::B2DPolygon& rPolyLine,
     double fTransparency,
-    const basegfx::B2DVector& rLineWidth,
+    double fLineWidth,
     const std::vector< double >* pStroke, // MM01
     basegfx::B2DLineJoin eLineJoin,
     css::drawing::LineCap eLineCap,
@@ -836,15 +836,15 @@ bool AquaSalGraphics::drawPolyLine(
 #endif
 
     // tdf#124848 get correct LineWidth in discrete coordinates,
-    // take hairline case into account
-    const basegfx::B2DVector aLineWidth(rLineWidth.equalZero()
-        ? basegfx::B2DVector(1.0, 1.0)
-        : rObjectToDevice * rLineWidth);
+    if(fLineWidth == 0) // hairline
+        fLineWidth = 1.0;
+    else // Adjust line width for object-to-device scale.
+        fLineWidth = (rObjectToDevice * basegfx::B2DVector(fLineWidth, 0)).getLength();
 
     // #i101491# Aqua does not support B2DLineJoin::NONE; return false to use
     // the fallback (own geometry preparation)
     // #i104886# linejoin-mode and thus the above only applies to "fat" lines
-    if( (basegfx::B2DLineJoin::NONE == eLineJoin) && (aLineWidth.getX() > 1.3) )
+    if( (basegfx::B2DLineJoin::NONE == eLineJoin) && (fLineWidth > 1.3) )
         return false;
 
     // MM01 need to do line dashing as fallback stuff here now
@@ -935,12 +935,7 @@ bool AquaSalGraphics::drawPolyLine(
         CGContextSetAlpha( maContextHolder.get(), 1.0 - fTransparency );
         CGContextSetLineJoin( maContextHolder.get(), aCGLineJoin );
         CGContextSetLineCap( maContextHolder.get(), aCGLineCap );
-
-        // aLineWidth.getX() can be negative here. That causes a warning that shows up in the debugger.
-        if (aLineWidth.getX() > 0)
-        {
-            CGContextSetLineWidth( maContextHolder.get(), aLineWidth.getX() );
-        }
+        CGContextSetLineWidth( maContextHolder.get(), fLineWidth );
         CGContextSetMiterLimit(maContextHolder.get(), fCGMiterLimit);
         CGContextDrawPath( maContextHolder.get(), kCGPathStroke );
         maContextHolder.restoreState();
diff --git a/vcl/skia/gdiimpl.cxx b/vcl/skia/gdiimpl.cxx
index bd55aaf8a044..00cf34d0eda6 100644
--- a/vcl/skia/gdiimpl.cxx
+++ b/vcl/skia/gdiimpl.cxx
@@ -650,7 +650,7 @@ void SkiaSalGraphicsImpl::drawPolyLine(sal_uInt32 nPoints, const SalPoint* pPtAr
         aPolygon.setB2DPoint(i, basegfx::B2DPoint(pPtAry[i].mnX, pPtAry[i].mnY));
     aPolygon.setClosed(false);
 
-    drawPolyLine(basegfx::B2DHomMatrix(), aPolygon, 0.0, basegfx::B2DVector(1.0, 1.0),
+    drawPolyLine(basegfx::B2DHomMatrix(), aPolygon, 0.0, 1.0,
                  nullptr, // MM01
                  basegfx::B2DLineJoin::Miter, css::drawing::LineCap_BUTT,
                  basegfx::deg2rad(15.0) /*default*/, false);
@@ -742,7 +742,7 @@ bool SkiaSalGraphicsImpl::drawPolyPolygon(const basegfx::B2DHomMatrix& rObjectTo
 
 bool SkiaSalGraphicsImpl::drawPolyLine(const basegfx::B2DHomMatrix& rObjectToDevice,
                                        const basegfx::B2DPolygon& rPolyLine, double fTransparency,
-                                       const basegfx::B2DVector& rLineWidth,
+                                       double fLineWidth,
                                        const std::vector<double>* pStroke, // MM01
                                        basegfx::B2DLineJoin eLineJoin,
                                        css::drawing::LineCap eLineCap, double fMiterMinimumAngle,
@@ -759,9 +759,10 @@ bool SkiaSalGraphicsImpl::drawPolyLine(const basegfx::B2DHomMatrix& rObjectToDev
     SAL_INFO("vcl.skia.trace", "drawpolyline(" << this << "): " << rPolyLine << ":" << mLineColor);
 
     // tdf#124848 get correct LineWidth in discrete coordinates,
-    // take hairline case into account
-    const basegfx::B2DVector aLineWidth(rLineWidth.equalZero() ? basegfx::B2DVector(1.0, 1.0)
-                                                               : rObjectToDevice * rLineWidth);
+    if (fLineWidth == 0) // hairline
+        fLineWidth = 1.0;
+    else // Adjust line width for object-to-device scale.
+        fLineWidth = (rObjectToDevice * basegfx::B2DVector(fLineWidth, 0)).getLength();
 
     // MM01 need to do line dashing as fallback stuff here now
     const double fDotDashLength(
@@ -833,7 +834,7 @@ bool SkiaSalGraphicsImpl::drawPolyLine(const basegfx::B2DHomMatrix& rObjectToDev
     aPaint.setStrokeJoin(eSkLineJoin);
     aPaint.setColor(toSkColorWithTransparency(mLineColor, fTransparency));
     aPaint.setStrokeMiter(fMiterLimit);
-    aPaint.setStrokeWidth(aLineWidth.getX());
+    aPaint.setStrokeWidth(fLineWidth);
     aPaint.setAntiAlias(mParent.getAntiAliasB2DDraw());
 
     if (eLineJoin != basegfx::B2DLineJoin::NONE)
diff --git a/vcl/source/gdi/FileDefinitionWidgetDraw.cxx b/vcl/source/gdi/FileDefinitionWidgetDraw.cxx
index 80bcda56b2a6..01698c4e3d6f 100644
--- a/vcl/source/gdi/FileDefinitionWidgetDraw.cxx
+++ b/vcl/source/gdi/FileDefinitionWidgetDraw.cxx
@@ -295,12 +295,11 @@ void drawFromDrawCommands(gfx::DrawRoot const& rDrawRoot, SalGraphics& rGraphics
                 {
                     rGraphics.SetLineColor(Color(*rRectangle.mpStrokeColor));
                     rGraphics.SetFillColor();
-                    rGraphics.DrawPolyLine(
-                        basegfx::B2DHomMatrix(), aB2DPolygon, 1.0 - rRectangle.mnOpacity,
-                        basegfx::B2DVector(rRectangle.mnStrokeWidth, rRectangle.mnStrokeWidth),
-                        nullptr, // MM01
-                        basegfx::B2DLineJoin::Round, css::drawing::LineCap_ROUND, 0.0f, false,
-                        nullptr);
+                    rGraphics.DrawPolyLine(basegfx::B2DHomMatrix(), aB2DPolygon,
+                                           1.0 - rRectangle.mnOpacity, rRectangle.mnStrokeWidth,
+                                           nullptr, // MM01
+                                           basegfx::B2DLineJoin::Round, css::drawing::LineCap_ROUND,
+                                           0.0f, false, nullptr);
                 }
             }
             break;
@@ -343,12 +342,11 @@ void drawFromDrawCommands(gfx::DrawRoot const& rDrawRoot, SalGraphics& rGraphics
                     rGraphics.SetFillColor();
                     for (auto const& rPolygon : aPolyPolygon)
                     {
-                        rGraphics.DrawPolyLine(
-                            basegfx::B2DHomMatrix(), rPolygon, 1.0 - rPath.mnOpacity,
-                            basegfx::B2DVector(rPath.mnStrokeWidth, rPath.mnStrokeWidth),
-                            nullptr, // MM01
-                            basegfx::B2DLineJoin::Round, css::drawing::LineCap_ROUND, 0.0f, false,
-                            nullptr);
+                        rGraphics.DrawPolyLine(basegfx::B2DHomMatrix(), rPolygon,
+                                               1.0 - rPath.mnOpacity, rPath.mnStrokeWidth,
+                                               nullptr, // MM01
+                                               basegfx::B2DLineJoin::Round,
+                                               css::drawing::LineCap_ROUND, 0.0f, false, nullptr);
                     }
                 }
             }
@@ -387,8 +385,7 @@ void munchDrawCommands(std::vector<std::shared_ptr<WidgetDrawAction>> const& rDr
                 rGraphics.SetLineColor(rWidgetDraw.maStrokeColor);
                 rGraphics.SetFillColor();
                 rGraphics.DrawPolyLine(
-                    basegfx::B2DHomMatrix(), aB2DPolygon, 0.0f,
-                    basegfx::B2DVector(rWidgetDraw.mnStrokeWidth, rWidgetDraw.mnStrokeWidth),
+                    basegfx::B2DHomMatrix(), aB2DPolygon, 0.0f, rWidgetDraw.mnStrokeWidth,
                     nullptr, // MM01
                     basegfx::B2DLineJoin::Round, css::drawing::LineCap_ROUND, 0.0f, false, nullptr);
             }
@@ -411,8 +408,7 @@ void munchDrawCommands(std::vector<std::shared_ptr<WidgetDrawAction>> const& rDr
                 };
 
                 rGraphics.DrawPolyLine(
-                    basegfx::B2DHomMatrix(), aB2DPolygon, 0.0f,
-                    basegfx::B2DVector(rWidgetDraw.mnStrokeWidth, rWidgetDraw.mnStrokeWidth),
+                    basegfx::B2DHomMatrix(), aB2DPolygon, 0.0f, rWidgetDraw.mnStrokeWidth,
                     nullptr, // MM01
                     basegfx::B2DLineJoin::Round, css::drawing::LineCap_ROUND, 0.0f, false, nullptr);
             }
diff --git a/vcl/source/gdi/salgdilayout.cxx b/vcl/source/gdi/salgdilayout.cxx
index 16a308064b12..0a50329f62f0 100644
--- a/vcl/source/gdi/salgdilayout.cxx
+++ b/vcl/source/gdi/salgdilayout.cxx
@@ -572,7 +572,7 @@ bool SalGraphics::DrawPolyLine(
     const basegfx::B2DHomMatrix& rObjectToDevice,
     const basegfx::B2DPolygon& i_rPolygon,
     double i_fTransparency,
-    const basegfx::B2DVector& i_rLineWidth,
+    double i_rLineWidth,
     const std::vector< double >* i_pStroke, // MM01
     basegfx::B2DLineJoin i_eLineJoin,
     css::drawing::LineCap i_eLineCap,
diff --git a/vcl/source/outdev/line.cxx b/vcl/source/outdev/line.cxx
index e88dd383e7f3..f451b6e1f645 100644
--- a/vcl/source/outdev/line.cxx
+++ b/vcl/source/outdev/line.cxx
@@ -128,8 +128,7 @@ void OutputDevice::DrawLine( const Point& rStartPt, const Point& rEndPt )
             basegfx::B2DHomMatrix(),
             aB2DPolyLine,
             0.0,
-            // tdf#124848 hairline
-            basegfx::B2DVector::getEmptyVector(),
+            0.0, // tdf#124848 hairline
             nullptr, // MM01
             basegfx::B2DLineJoin::NONE,
             css::drawing::LineCap_BUTT,
@@ -241,8 +240,7 @@ void OutputDevice::drawLine( basegfx::B2DPolyPolygon aLinePolyPolygon, const Lin
                     basegfx::B2DHomMatrix(),
                     rB2DPolygon,
                     0.0,
-                    // tdf#124848 hairline
-                    basegfx::B2DVector::getEmptyVector(),
+                    0.0, // tdf#124848 hairline
                     nullptr, // MM01
                     basegfx::B2DLineJoin::NONE,
                     css::drawing::LineCap_BUTT,
diff --git a/vcl/source/outdev/polygon.cxx b/vcl/source/outdev/polygon.cxx
index c742379d39de..60deaceb822c 100644
--- a/vcl/source/outdev/polygon.cxx
+++ b/vcl/source/outdev/polygon.cxx
@@ -96,8 +96,7 @@ void OutputDevice::DrawPolyPolygon( const tools::PolyPolygon& rPolyPoly )
                     aTransform,
                     rPolygon,
                     0.0,
-                    // tdf#124848 hairline
-                    basegfx::B2DVector::getEmptyVector(),
+                    0.0, // tdf#124848 hairline
                     nullptr, // MM01
                     basegfx::B2DLineJoin::NONE,
                     css::drawing::LineCap_BUTT,
@@ -215,8 +214,7 @@ void OutputDevice::DrawPolygon( const tools::Polygon& rPoly )
                 aTransform,
                 aB2DPolygon,
                 0.0,
-                // tdf#124848 hairline
-                basegfx::B2DVector::getEmptyVector(),
+                0.0, // tdf#124848 hairline
                 nullptr, // MM01
                 basegfx::B2DLineJoin::NONE,
                 css::drawing::LineCap_BUTT,
@@ -326,8 +324,7 @@ void OutputDevice::ImplDrawPolyPolygonWithB2DPolyPolygon(const basegfx::B2DPolyP
                     aTransform,
                     rPolygon,
                     0.0,
-                    // tdf#124848 hairline
-                    basegfx::B2DVector::getEmptyVector(),
+                    0.0, // tdf#124848 hairline
                     nullptr, // MM01
                     basegfx::B2DLineJoin::NONE,
                     css::drawing::LineCap_BUTT,
diff --git a/vcl/source/outdev/polyline.cxx b/vcl/source/outdev/polyline.cxx
index 3e2ed372e01b..d17056d58e13 100644
--- a/vcl/source/outdev/polyline.cxx
+++ b/vcl/source/outdev/polyline.cxx
@@ -71,8 +71,7 @@ void OutputDevice::DrawPolyLine( const tools::Polygon& rPoly )
         aTransform,
         aB2DPolyLine,
         0.0,
-        // tdf#124848 hairline
-        basegfx::B2DVector::getEmptyVector(),
+        0.0, // tdf#124848 hairline
         nullptr, // MM01
         basegfx::B2DLineJoin::NONE,
         css::drawing::LineCap_BUTT,
@@ -348,8 +347,7 @@ bool OutputDevice::DrawPolyLineDirect(
             aTransform,
             rB2DPolygon,
             fTransparency,
-            // tdf#124848 use LineWidth direct, do not try to solve for zero-case (aka hairline)
-            basegfx::B2DVector(fLineWidth, fLineWidth),
+            fLineWidth, // tdf#124848 use LineWidth direct, do not try to solve for zero-case (aka hairline)
             pStroke, // MM01
             eLineJoin,
             eLineCap,
diff --git a/vcl/source/outdev/textline.cxx b/vcl/source/outdev/textline.cxx
index a6eaa6b1c3a7..6ade6113fc99 100644
--- a/vcl/source/outdev/textline.cxx
+++ b/vcl/source/outdev/textline.cxx
@@ -1004,7 +1004,6 @@ void OutputDevice::DrawWaveLine(const Point& rStartPos, const Point& rEndPos, lo
     const basegfx::B2DRectangle aWaveLineRectangle(nStartX, nStartY, nEndX, nEndY + nWaveHeight);
     const basegfx::B2DPolygon aWaveLinePolygon = basegfx::createWaveLinePolygon(aWaveLineRectangle);
     const basegfx::B2DHomMatrix aRotationMatrix = basegfx::utils::createRotateAroundPoint(nStartX, nStartY, basegfx::deg2rad(-fOrientation));
-    const basegfx::B2DVector aLineWidth(nLineWidth, nLineWidth);
     const bool bPixelSnapHairline(mnAntialiasing & AntialiasingFlags::PixelSnapHairline);
 
     mpGraphics->SetLineColor(GetLineColor());
@@ -1012,7 +1011,7 @@ void OutputDevice::DrawWaveLine(const Point& rStartPos, const Point& rEndPos, lo
             aRotationMatrix,
             aWaveLinePolygon,
             0.0,
-            aLineWidth,
+            nLineWidth,
             nullptr, // MM01
             basegfx::B2DLineJoin::NONE,
             css::drawing::LineCap_BUTT,
diff --git a/vcl/source/outdev/transparent.cxx b/vcl/source/outdev/transparent.cxx
index 0cf325d0b40a..e35d4dfbf959 100644
--- a/vcl/source/outdev/transparent.cxx
+++ b/vcl/source/outdev/transparent.cxx
@@ -269,8 +269,7 @@ void OutputDevice::DrawTransparent(
                     aFullTransform,
                     rPolygon,
                     fTransparency,
-                    // tdf#124848 hairline
-                    basegfx::B2DVector::getEmptyVector(),
+                    0.0, // tdf#124848 hairline
                     nullptr, // MM01
                     basegfx::B2DLineJoin::NONE,
                     css::drawing::LineCap_BUTT,
@@ -392,8 +391,7 @@ bool OutputDevice::DrawTransparentNatively ( const tools::PolyPolygon& rPolyPoly
                     aTransform,
                     rPolygon,
                     fTransparency,
-                    // tdf#124848 hairline
-                    basegfx::B2DVector::getEmptyVector(),
+                    0.0, // tdf#124848 hairline
                     nullptr, // MM01
                     basegfx::B2DLineJoin::NONE,
                     css::drawing::LineCap_BUTT,
diff --git a/vcl/unx/generic/gdi/gdiimpl.cxx b/vcl/unx/generic/gdi/gdiimpl.cxx
index 99884a4c0941..ee45815a7c83 100644
--- a/vcl/unx/generic/gdi/gdiimpl.cxx
+++ b/vcl/unx/generic/gdi/gdiimpl.cxx
@@ -1582,7 +1582,7 @@ private:
 
     // all other values the triangulation is based on and
     // need to be compared with to check for data validity
-    basegfx::B2DVector                          maLineWidth;
+    double                                      mfLineWidth;
     basegfx::B2DLineJoin                        meJoin;
     css::drawing::LineCap                       meCap;
     double                                      mfMiterMinimumAngle;
@@ -1592,7 +1592,7 @@ public:
     SystemDependentData_Triangulation(
         basegfx::SystemDependentDataManager& rSystemDependentDataManager,
         const basegfx::triangulator::B2DTriangleVector& rTriangles,
-        const basegfx::B2DVector& rLineWidth,
+        double fLineWidth,
         basegfx::B2DLineJoin eJoin,
         css::drawing::LineCap eCap,
         double fMiterMinimumAngle,
@@ -1600,7 +1600,7 @@ public:
 
     // read access
     const basegfx::triangulator::B2DTriangleVector& getTriangles() const { return maTriangles; }
-    const basegfx::B2DVector& getLineWidth() const { return maLineWidth; }
+    double getLineWidth() const { return mfLineWidth; }
     const basegfx::B2DLineJoin& getJoin() const { return meJoin; }
     const css::drawing::LineCap& getCap() const { return meCap; }
     double getMiterMinimumAngle() const { return mfMiterMinimumAngle; }
@@ -1614,14 +1614,14 @@ public:
 SystemDependentData_Triangulation::SystemDependentData_Triangulation(
     basegfx::SystemDependentDataManager& rSystemDependentDataManager,
     const basegfx::triangulator::B2DTriangleVector& rTriangles,
-    const basegfx::B2DVector& rLineWidth,
+    double fLineWidth,
     basegfx::B2DLineJoin eJoin,
     css::drawing::LineCap eCap,
     double fMiterMinimumAngle,
     const std::vector< double >* pStroke)
 :   basegfx::SystemDependentData(rSystemDependentDataManager),
     maTriangles(rTriangles),
-    maLineWidth(rLineWidth),
+    mfLineWidth(fLineWidth),
     meJoin(eJoin),
     meCap(eCap),
     mfMiterMinimumAngle(fMiterMinimumAngle),
@@ -1649,7 +1649,7 @@ bool X11SalGraphicsImpl::drawPolyLine(
     const basegfx::B2DHomMatrix& rObjectToDevice,
     const basegfx::B2DPolygon& rPolygon,
     double fTransparency,
-    const basegfx::B2DVector& rLineWidth,
+    double fLineWidth,
     const std::vector< double >* pStroke, // MM01
     basegfx::B2DLineJoin eLineJoin,
     css::drawing::LineCap eLineCap,
@@ -1663,7 +1663,6 @@ bool X11SalGraphicsImpl::drawPolyLine(
     }
 
     // need to check/handle LineWidth when ObjectToDevice transformation is used
-    basegfx::B2DVector aLineWidth(rLineWidth);
     const bool bObjectToDeviceIsIdentity(rObjectToDevice.isIdentity());
     basegfx::B2DHomMatrix aObjectToDeviceInv;
 
@@ -1672,9 +1671,9 @@ bool X11SalGraphicsImpl::drawPolyLine(
     // the graphic sub-system, but the triangulation data is prepared
     // view-independent based on the logic LineWidth, so we need to
     // know it
-    if(aLineWidth.equalZero())
+    if(fLineWidth == 0)
     {
-        aLineWidth = basegfx::B2DVector(1.0, 1.0);
+        fLineWidth = 1.0;
 
         if(!bObjectToDeviceIsIdentity)
         {
@@ -1684,7 +1683,7 @@ bool X11SalGraphicsImpl::drawPolyLine(
                 aObjectToDeviceInv.invert();
             }
 
-            aLineWidth = aObjectToDeviceInv * aLineWidth;
+            fLineWidth = (aObjectToDeviceInv * basegfx::B2DVector(fLineWidth, 0)).getLength();
         }
     }
 
@@ -1727,18 +1726,14 @@ bool X11SalGraphicsImpl::drawPolyLine(
     if(pSystemDependentData_Triangulation)
     {
         // check data validity (II)
-        if(pSystemDependentData_Triangulation->getLineWidth() != aLineWidth)
+        if(pSystemDependentData_Triangulation->getLineWidth() != fLineWidth)
         {
             // sometimes small inconsistencies, use a percentage tolerance
-            const double fFactorX(basegfx::fTools::equalZero(aLineWidth.getX())
+            const double fFactor(basegfx::fTools::equalZero(fLineWidth)
                 ? 0.0
-                : fabs(1.0 - (pSystemDependentData_Triangulation->getLineWidth().getX() / aLineWidth.getX())));
-            const double fFactorY(basegfx::fTools::equalZero(aLineWidth.getY())
-                ? 0.0
-                : fabs(1.0 - (pSystemDependentData_Triangulation->getLineWidth().getY() / aLineWidth.getY())));
-
+                : fabs(1.0 - (pSystemDependentData_Triangulation->getLineWidth() / fLineWidth)));
             // compare with 5.0% tolerance
-            if(basegfx::fTools::more(fFactorX, 0.05) || basegfx::fTools::more(fFactorY, 0.05))
+            if(basegfx::fTools::more(fFactor, 0.05))
             {
                 // data invalid, forget
                 pSystemDependentData_Triangulation.reset();
@@ -1803,7 +1798,7 @@ bool X11SalGraphicsImpl::drawPolyLine(
             // aTriangles data (!)
             basegfx::utils::createAreaGeometry(
                 aPolyLine,
-                0.5 * aLineWidth.getX(),
+                0.5 * fLineWidth,
                 eLineJoin,
                 eLineCap,
                 basegfx::deg2rad(12.5),
@@ -1820,7 +1815,7 @@ bool X11SalGraphicsImpl::drawPolyLine(
             pSystemDependentData_Triangulation = rPolygon.addOrReplaceSystemDependentData<SystemDependentData_Triangulation>(
                 ImplGetSystemDependentDataManager(),
                 aTriangles,
-                aLineWidth,
+                fLineWidth,
                 eLineJoin,
                 eLineCap,
                 fMiterMinimumAngle,
diff --git a/vcl/unx/generic/gdi/gdiimpl.hxx b/vcl/unx/generic/gdi/gdiimpl.hxx
index 9a4940eab7d0..061993bb80df 100644
--- a/vcl/unx/generic/gdi/gdiimpl.hxx
+++ b/vcl/unx/generic/gdi/gdiimpl.hxx
@@ -171,7 +171,7 @@ public:
                 const basegfx::B2DHomMatrix& rObjectToDevice,
                 const basegfx::B2DPolygon&,
                 double fTransparency,
-                const basegfx::B2DVector& rLineWidths,
+                double fLineWidth,
                 const std::vector< double >* pStroke, // MM01
                 basegfx::B2DLineJoin,
                 css::drawing::LineCap,
diff --git a/vcl/unx/generic/gdi/salgdi.cxx b/vcl/unx/generic/gdi/salgdi.cxx
index eeb67195dfb7..3ecbe013a88d 100644
--- a/vcl/unx/generic/gdi/salgdi.cxx
+++ b/vcl/unx/generic/gdi/salgdi.cxx
@@ -702,7 +702,7 @@ bool X11SalGraphics::drawPolyLine(
     const basegfx::B2DHomMatrix& rObjectToDevice,
     const basegfx::B2DPolygon& rPolygon,
     double fTransparency,
-    const basegfx::B2DVector& rLineWidth,
+    double fLineWidth,
     const std::vector< double >* pStroke, // MM01
     basegfx::B2DLineJoin eLineJoin,
     css::drawing::LineCap eLineCap,
@@ -739,7 +739,7 @@ bool X11SalGraphics::drawPolyLine(
                 rObjectToDevice,
                 rPolygon,
                 fTransparency,
-                rLineWidth,
+                fLineWidth,
                 pStroke, // MM01
                 eLineJoin,
                 eLineCap,
@@ -759,7 +759,7 @@ bool X11SalGraphics::drawPolyLine(
         rObjectToDevice,
         rPolygon,
         fTransparency,
-        rLineWidth,
+        fLineWidth,
         pStroke, // MM01
         eLineJoin,
         eLineCap,
diff --git a/vcl/unx/generic/print/genpspgraphics.cxx b/vcl/unx/generic/print/genpspgraphics.cxx
index f9bb988047c5..86044621e4ad 100644
--- a/vcl/unx/generic/print/genpspgraphics.cxx
+++ b/vcl/unx/generic/print/genpspgraphics.cxx
@@ -432,7 +432,7 @@ bool GenPspGraphics::drawPolyLine(
     const basegfx::B2DHomMatrix& /* rObjectToDevice */,
     const basegfx::B2DPolygon&,
     double /*fTransparency*/,
-    const basegfx::B2DVector& /*rLineWidths*/,
+    double /*fLineWidth*/,
     const std::vector< double >* /*pStroke*/, // MM01
     basegfx::B2DLineJoin /*eJoin*/,
     css::drawing::LineCap /*eLineCap*/,
diff --git a/vcl/win/gdi/gdiimpl.cxx b/vcl/win/gdi/gdiimpl.cxx
index 08c5f7861e8e..b019692726eb 100644
--- a/vcl/win/gdi/gdiimpl.cxx
+++ b/vcl/win/gdi/gdiimpl.cxx
@@ -2204,7 +2204,7 @@ bool WinSalGraphicsImpl::drawPolyLine(
     const basegfx::B2DHomMatrix& rObjectToDevice,
     const basegfx::B2DPolygon& rPolygon,
     double fTransparency,
-    const basegfx::B2DVector& rLineWidth,
+    double fLineWidth,
     const std::vector< double >* pStroke, // MM01
     basegfx::B2DLineJoin eLineJoin,
     css::drawing::LineCap eLineCap,
@@ -2218,29 +2218,28 @@ bool WinSalGraphicsImpl::drawPolyLine(
     }
 
     // need to check/handle LineWidth when ObjectToDevice transformation is used
-    basegfx::B2DVector aLineWidth(rLineWidth);
     const bool bObjectToDeviceIsIdentity(rObjectToDevice.isIdentity());
-    const bool bIsHairline(aLineWidth.equalZero());
+    const bool bIsHairline(fLineWidth == 0);
 
     // tdf#124848 calculate-back logical LineWidth for a hairline
     // since this implementation hands over the transformation to
     // the graphic sub-system
     if(bIsHairline)
     {
-        aLineWidth = basegfx::B2DVector(1.0, 1.0);
+        fLineWidth = 1.0;
 
         if(!bObjectToDeviceIsIdentity)
         {
             basegfx::B2DHomMatrix aObjectToDeviceInv(rObjectToDevice);
             aObjectToDeviceInv.invert();
-            aLineWidth = aObjectToDeviceInv * aLineWidth;
+            fLineWidth = (aObjectToDeviceInv * basegfx::B2DVector(fLineWidth, 0)).getLength();
         }
     }
 
     Gdiplus::Graphics aGraphics(mrParent.getHDC());
     const sal_uInt8 aTrans = static_cast<sal_uInt8>(basegfx::fround( 255 * (1.0 - fTransparency) ));
     const Gdiplus::Color aTestColor(aTrans, maLineColor.GetRed(), maLineColor.GetGreen(), maLineColor.GetBlue());
-    Gdiplus::Pen aPen(aTestColor.GetValue(), Gdiplus::REAL(aLineWidth.getX()));
+    Gdiplus::Pen aPen(aTestColor.GetValue(), Gdiplus::REAL(fLineWidth));
     bool bNoLineJoin(false);
 
     // Set full (Object-to-Device) transformation - if used
@@ -2340,7 +2339,7 @@ bool WinSalGraphicsImpl::drawPolyLine(
         // the back-calculated logical linewidth is already here, just use it.
         // Still be careful - a zero LineWidth *should* not happen, but...
         std::vector<Gdiplus::REAL> aDashArray(pStroke->size());
-        const double fFactor(aLineWidth.equalZero() ? 1.0 : 1.0 / aLineWidth.getX());
+        const double fFactor(fLineWidth == 0 ? 1.0 : 1.0 / fLineWidth);
 
         for(size_t a(0); a < pStroke->size(); a++)
         {
diff --git a/vcl/win/gdi/gdiimpl.hxx b/vcl/win/gdi/gdiimpl.hxx
index eb56388ff42d..748afbcf04d4 100644
--- a/vcl/win/gdi/gdiimpl.hxx
+++ b/vcl/win/gdi/gdiimpl.hxx
@@ -129,7 +129,7 @@ public:
                 const basegfx::B2DHomMatrix& rObjectToDevice,
                 const basegfx::B2DPolygon&,
                 double fTransparency,
-                const basegfx::B2DVector& rLineWidths,
+                double fLineWidth,
                 const std::vector< double >* pStroke, // MM01
                 basegfx::B2DLineJoin,
                 css::drawing::LineCap,
diff --git a/vcl/win/gdi/salgdi_gdiplus.cxx b/vcl/win/gdi/salgdi_gdiplus.cxx
index ce2f2cc69c20..f56a227609f9 100644
--- a/vcl/win/gdi/salgdi_gdiplus.cxx
+++ b/vcl/win/gdi/salgdi_gdiplus.cxx
@@ -41,7 +41,7 @@ bool WinSalGraphics::drawPolyLine(
     const basegfx::B2DHomMatrix& rObjectToDevice,
     const basegfx::B2DPolygon& rPolygon,
     double fTransparency,
-    const basegfx::B2DVector& rLineWidths,
+    double fLineWidth,
     const std::vector< double >* pStroke, // MM01
     basegfx::B2DLineJoin eLineJoin,
     css::drawing::LineCap eLineCap,
@@ -52,7 +52,7 @@ bool WinSalGraphics::drawPolyLine(
         rObjectToDevice,
         rPolygon,
         fTransparency,
-        rLineWidths,
+        fLineWidth,
         pStroke, // MM01
         eLineJoin,
         eLineCap,