Trying to digitize a floor plan for a building (just need polygons for each room) in QGIS (shapefile layer).  I started just trying to draw the features, but want to align polygons so that there is no gap or overlap.   That led me to the Snapping features which helped a lot.  But having trouble making sure my rectangles have 90 degree corners.  

Then I discovered the rectangles ovals digitizing tool which solves that problem.  Unfortunately--it seems to ignore the "snapping" that I got when just drawing features node to node.  Is there a way to get both snapping and rectangles in QGIS?