Refinement of math from previous check-in (avoiding some DOM calls)
Refinement of math from previous check-in (avoiding some DOM calls)

trentmillar/ddp-level-editor,ryanramage/svg-editor,ryanramage/svg-editor,ryanramage/svg-editor,trentmillar/ddp-level-editor,trentmillar/ddp-level-editor