tdf#129916 svx: fix origin of scaled shadow

We assumed that the top left corner is the origin for scaling, but that
is not necessarily the case. The intention is that the shadow direction
can be determined from its x and y offset, and the origin is the
opposite corner of the shape.

(cherry picked from commit e21d522dddce2590ed435890ae8d5fe39658a71a)

Conflicts:
svx/CppunitTest_svx_unit.mk

Change-Id: I6759302767d20739b6e2be79d379740dd06f70f5

1 files changed, 12 insertions, 2 deletions

diff --git a/svx/source/sdr/primitive2d/sdrdecompositiontools.cxx b/svx/source/sdr/primitive2d/sdrdecompositiontools.cxx
index 42c0bb60ecc9..48575d3b4917 100644
--- a/svx/source/sdr/primitive2d/sdrdecompositiontools.cxx
+++ b/svx/source/sdr/primitive2d/sdrdecompositiontools.cxx
@@ -499,9 +499,19 @@ namespace drawinglayer
                         double fShearX = 0;
                         rObjectMatrix.decompose(aScale, aTranslate, fRotate, fShearX);
                         // Scale the shadow
-                        aShadowOffset.translate(-aTranslate.getX(), -aTranslate.getY());
+                        double nTranslateX = aTranslate.getX();
+                        double nTranslateY = aTranslate.getY();
+
+                        // The origin for scaling is the top left corner by default. A negative
+                        // shadow offset changes the origin.
+                        if (rShadow.getOffset().getX() < 0)
+                            nTranslateX += aScale.getX();
+                        if (rShadow.getOffset().getY() < 0)
+                            nTranslateY += aScale.getY();
+
+                        aShadowOffset.translate(-nTranslateX, -nTranslateY);
                         aShadowOffset.scale(rShadow.getSize().getX() * 0.00001, rShadow.getSize().getY() * 0.00001);
-                        aShadowOffset.translate(aTranslate.getX(), aTranslate.getY());
+                        aShadowOffset.translate(nTranslateX, nTranslateY);
                     }
 
                     aShadowOffset.translate(rShadow.getOffset().getX(), rShadow.getOffset().getY());