Weird behaviour when detail area is larger than zoomed image dimensions

[frederickfogerty]

Checklist:

• I have checked stackoverflow for this bug and there are no answers or the question does not exist
• I have searched through the issue list for related bugs or issues

Describe the bug
When the high-resolution (i.e. image that shows up in the zoom pane) is a lower resolution than the dimensions of the detail pane, panning around the image is jumpy.

To Reproduce

https://codepen.io/imgix/pen/mKWZqq

Steps to reproduce the behaviour:

1. Hover over the top-left corner of the image.
2. Move cursor to the very top-right corner of the image

Expected behaviour
The zoom pane stays in a consistent position when panning around the image.

Screenshots
When cursor is over left side of image:

When cursor is over very right side of image:

Information:

• drift version: v1.2.0
• browser version: whatsmybrowser.org/b/SBFRP96

[frederickfogerty]

Fixed in #69