center bodies in x-direction at zero

dune/tectonic/factories/twoblocksfactory.cc

@@ -36,8 +36,8 @@ void TwoBlocksFactory<HostGridType, VectorTEMPLATE>::setBodies() {
         cuboidGeometries_[1] = std::make_shared<CuboidGeometry>(origins[1], lengths[1], heights[1], depths[1]);
         cuboidGeometries_[1]->addWeakeningPatch(frictionParset, origins[1], {origins[1][0] + lengths[1], origins[1][1], 0});
 #elif MY_DIM == 2
-        origins[0] = {0, 0};
-        origins[1] = {lengths[0]/2.0, origins[0][1] + heights[0]};
+        origins[0] = {-lengths[0]/2.0, 0};
+        origins[1] = {-lengths[1]/2.0, origins[0][1] + heights[0]};
 
         cuboidGeometries_[0] = std::make_shared<CuboidGeometry>(origins[0], lengths[0], heights[0]);
         cuboidGeometries_[0]->addWeakeningPatch(frictionParset, {origins[0][0], origins[0][1]+ heights[0]}, {origins[0][0] + lengths[0], origins[0][1]+ heights[0]});