tdf#145245 correct relative position of extrusion

ODF specifies for draw:extrusion-depth, 'The draw:extrusion-depth
attribute specifies the depth of an extrusion. It takes two white space
separated values. The first value specifies the depth of the extrusion
in units, the second value specifies the fraction of the extrusion that
lies before a shape. The second value shall be in the range [0,1].'

The default for the second value is 0. Because LibreOffice has no UI to
change the value, the error becomes only visible, if you create own
custom shapes.

On import the ODF values are put in CustomShapeGeometry>Extrusion>
Depth. Method GetExtrusionDepth() calculates from that the length
values rBackwardDepth and rForwardDepth so that its sum is the depth.

CreateCustomShapeProperties() in escherex.cxx#2699 and
ApplyCustomShapeGeometryAttributes() in msdffimp.cxx#1684 use them in
the same sence.

But methods Create3DObject() and CalculateNewSnapRect() in
EnhancedCustomShape3d.cxx have used these values as if they were
coordinates.

I have keept the calculation in GetExtrusionDepth(), because it
reflects the meaning in ODF. I have corrected the signs in
Create3DObject() and CalculateNewSnapRect().

Change-Id: If275bb263b6f3d790f5893a69f38f8433acfbe7f
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/123997
Tested-by: Jenkins
Reviewed-by: Regina Henschel <rb.henschel@t-online.de>

3 files changed, 45 insertions, 2 deletions

diff --git a/svx/qa/unit/customshapes.cxx b/svx/qa/unit/customshapes.cxx
index d4e7ff045fe1..92fbfc9fa62e 100644
--- a/svx/qa/unit/customshapes.cxx
+++ b/svx/qa/unit/customshapes.cxx
@@ -127,6 +127,49 @@ void lcl_AssertRectEqualWithTolerance(std::string_view sInfo, const tools::Recta
                            std::abs(rExpected.GetHeight() - rActual.GetHeight()) <= nTolerance);
 }
 
+CPPUNIT_TEST_FIXTURE(CustomshapesTest, testTdf145245_ExtrusionPosition)
+{
+    // The second parameter of the extrusion-depth property specifies how much of the extrusion
+    // lies before the shape. The file contains three shapes which have the values 0, 0.5 and 1.
+    // They are rotated around the x-axis so that the extrusion becomes visible. The extrusion
+    // depth itself is 5cm. Y-coordinate of shape is 6cm.
+
+    // Load document
+    OUString aURL = m_directories.getURLFromSrc(sDataDirectory) + "tdf145245_ExtrusionPosition.odp";
+    mxComponent = loadFromDesktop(aURL, "com.sun.star.comp.presentation.PresentationDocument");
+
+    // The tolerance 40 is estimated and can be adjusted if required for HiDPI.
+    {
+        // First shape has extrusion behind the shape.
+        uno::Reference<drawing::XShape> xShape0(getShape(0));
+        SdrObjCustomShape& rSdrCustomShape(
+            static_cast<SdrObjCustomShape&>(*SdrObject::getSdrObjectFromXShape(xShape0)));
+        tools::Rectangle aBoundRect(rSdrCustomShape.GetCurrentBoundRect());
+        tools::Rectangle aExpected(Point(1000, 1000), Size(6002, 5001));
+        lcl_AssertRectEqualWithTolerance("Pos 0.0 extrusion", aExpected, aBoundRect, 40);
+    }
+    {
+        // Second shape has half of extrusion behind the shape.
+        uno::Reference<drawing::XShape> xShape(getShape(1));
+        SdrObjCustomShape& rSdrCustomShape(
+            static_cast<SdrObjCustomShape&>(*SdrObject::getSdrObjectFromXShape(xShape)));
+        // Without the fix the height was 1 instead of 5001.
+        tools::Rectangle aBoundRect(rSdrCustomShape.GetCurrentBoundRect());
+        tools::Rectangle aExpected(Point(9000, 3500), Size(6002, 5001));
+        lcl_AssertRectEqualWithTolerance("Pos 0.5 extrusion", aExpected, aBoundRect, 40);
+    }
+    {
+        // Third shape has extrusion before the shape.
+        uno::Reference<drawing::XShape> xShape(getShape(2));
+        SdrObjCustomShape& rSdrCustomShape(
+            static_cast<SdrObjCustomShape&>(*SdrObject::getSdrObjectFromXShape(xShape)));
+        // Without the fix the y-coordinate was 1000 instead of 6000.
+        tools::Rectangle aBoundRect(rSdrCustomShape.GetCurrentBoundRect());
+        tools::Rectangle aExpected(Point(18000, 6000), Size(6002, 5001));
+        lcl_AssertRectEqualWithTolerance("Pos 1.0 extrusion", aExpected, aBoundRect, 40);
+    }
+}
+
 CPPUNIT_TEST_FIXTURE(CustomshapesTest, testTdf145111_Fontwork_rendering_font_size)
 {
     // The tested position and height depend on dpi.
diff --git a/svx/qa/unit/data/tdf145245_ExtrusionPosition.odp b/svx/qa/unit/data/tdf145245_ExtrusionPosition.odp
new file mode 100644
index 000000000000..a356cf9ed396
--- /dev/null
+++ b/svx/qa/unit/data/tdf145245_ExtrusionPosition.odp
diff --git a/svx/source/customshapes/EnhancedCustomShape3d.cxx b/svx/source/customshapes/EnhancedCustomShape3d.cxx
index 2f13eb8b986b..b6e3e04234ab 100644
--- a/svx/source/customshapes/EnhancedCustomShape3d.cxx
+++ b/svx/source/customshapes/EnhancedCustomShape3d.cxx
@@ -304,7 +304,7 @@ SdrObject* EnhancedCustomShape3d::Create3DObject(
 
         double fExtrusionBackward, fExtrusionForward;
         GetExtrusionDepth( rGeometryItem, pMap, fExtrusionBackward, fExtrusionForward );
-        double fDepth = fExtrusionBackward - fExtrusionForward;
+        double fDepth = fExtrusionBackward + fExtrusionForward;
         if ( fDepth < 1.0 )
             fDepth = 1.0;
 
@@ -768,7 +768,7 @@ tools::Rectangle EnhancedCustomShape3d::CalculateNewSnapRect(
 
     for ( i = 0; i < 4; i++ )
     {
-        aBoundVolume.append(basegfx::B3DPoint(aPolygon[ static_cast<sal_uInt16>(i) ].X() - aCenter.X(), aPolygon[ static_cast<sal_uInt16>(i) ].Y() - aCenter.Y(), fExtrusionForward));
+        aBoundVolume.append(basegfx::B3DPoint(aPolygon[ static_cast<sal_uInt16>(i) ].X() - aCenter.X(), aPolygon[ static_cast<sal_uInt16>(i) ].Y() - aCenter.Y(), -fExtrusionForward));
     }
 
     for ( i = 0; i < 4; i++ )