improved B2DHomMatrix

since we know that this is a matrix only used for 2D transforms,
we know that the last row of the matrix is always { 0, 0, 1 }.

Therefore, we don't need to store that information, and
we can simplify some of the computations.

Also remove operations like operator+ which are not legal for
such a matrix.

Change-Id: I482de9a45ebbedf79e3b6033575aab590e61c2d5
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/151909
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

1 files changed, 7 insertions, 6 deletions

diff --git a/svx/source/unodraw/unoshape.cxx b/svx/source/unodraw/unoshape.cxx
index f46727299cef..8494f493513d 100644
--- a/svx/source/unodraw/unoshape.cxx
+++ b/svx/source/unodraw/unoshape.cxx
@@ -2076,9 +2076,10 @@ bool SvxShape::setPropertyValueImpl( const OUString&, const SfxItemPropertyMapEn
             aNewHomogenMatrix.set(1, 0, aMatrix.Line2.Column1);
             aNewHomogenMatrix.set(1, 1, aMatrix.Line2.Column2);
             aNewHomogenMatrix.set(1, 2, aMatrix.Line2.Column3);
-            aNewHomogenMatrix.set(2, 0, aMatrix.Line3.Column1);
-            aNewHomogenMatrix.set(2, 1, aMatrix.Line3.Column2);
-            aNewHomogenMatrix.set(2, 2, aMatrix.Line3.Column3);
+            // For this to be a valid 2D transform matrix, the last row must be [0,0,1]
+            assert( aMatrix.Line3.Column1 == 0 );
+            assert( aMatrix.Line3.Column2 == 0 );
+            assert( aMatrix.Line3.Column3 == 1 );
 
             // tdf#117145 metric of SdrModel is app-specific, metric of UNO API is 100thmm
             // Need to adapt aNewHomogenMatrix from 100thmm to app-specific
@@ -2578,9 +2579,9 @@ bool SvxShape::getPropertyValueImpl( const OUString&, const SfxItemPropertyMapEn
         aMatrix.Line2.Column1 = aNewHomogenMatrix.get(1, 0);
         aMatrix.Line2.Column2 = aNewHomogenMatrix.get(1, 1);
         aMatrix.Line2.Column3 = aNewHomogenMatrix.get(1, 2);
-        aMatrix.Line3.Column1 = aNewHomogenMatrix.get(2, 0);
-        aMatrix.Line3.Column2 = aNewHomogenMatrix.get(2, 1);
-        aMatrix.Line3.Column3 = aNewHomogenMatrix.get(2, 2);
+        aMatrix.Line3.Column1 = 0;
+        aMatrix.Line3.Column2 = 0;
+        aMatrix.Line3.Column3 = 1;
 
         rValue <<= aMatrix;