Bingliang

After digging into the source code, I'm pretty sure `viewport.worldToCanvas` is the root cause. [multiVolumeCanvasToWorld](https://www.cornerstonejs.org/live-examples/multiVolumeCanvasToWorld.html) and [stackcanvastoworld](https://www.cornerstonejs.org/live-examples/stackcanvastoworld) also have this bug when browser zoom in/out. The canvas' value is correct,...

I think the remaining 8 issues checked by codeclimate are not so urgent to be fixed. Go on finishing other parts.

There are some dependencies issues need Node 10. Would be nice to see travis-ci's node version being updated. All npm scripts are checked.

I need some feedback.

Travis CI failed due to this, how can I upgrade that? > error @typescript-eslint/[email protected]: The engine "node" is incompatible with this module. Expected version "^8.10.0 || ^10.13.0 || >=11.10.1". Got...