Background

This issue has been raised in the Slack channel:

When using the IconLayer with auto packing, the application may not know the dimensions of an icon before loading it. Providing the wrong width/height will cause the rendered icon to be stretched.

After this PR, the IconManager preserves the aspect ratio of the incoming icon image while resizing.

This is technically a breaking change with no way of reverting to the old behavior. I would argue that it is the expected behavior, though.

Other caveats:

• The packing algorithm is still run before any icon is loaded using the user-provided width/height, so there may end up being some empty pixels in the texture when all is loaded. However, this way we only have to resize the texture once.
• If an icon image's aspect ratio is different from the pre-defined dimension, the pixels are centered in the provided bounding box. The default anchorX/anchorY (center of bounding box) will not be affected, but other values may appear off.

Change List

• IconManager preserve aspect ratio when auto packing
• Unit test