A blue button is begging to be clicked, but clicking it will do nothing. Instead, we should communicate that no action is needed by disabling the button when the default settings are already in use.
Using `&&` will result in false negatives for settings where a falsy value might be valid. For example, any setting for which 0 is a valid number. To be on the safe side, just use an explicit null check on all values.
We use an in-memory cache for PIL images to reduce I/O. If a node mutates the image in any way, the cached image object is also updated (but the on-disk image file is not).
We've lucked out that this hasn't caused major issues in the past (well, maybe it has but we didn't understand them?) mainly because of a happy accident. When you call `context.images.get_pil` in a node, if you provide an image mode (e.g. `mode="RGB"`), we call `convert` on the image. This returns a copy. The node can do whatever it wants to that copy and nothing breaks.
However, when mode is not specified, we return the image directly. This is where we get in trouble - nodes that load the image like this, and then mutate the image, update the cache. Other nodes that reference that same image will now get the mutated version of it.
The fix is super simple - we make sure to return only copies from `get_pil`.
- Use a hash of the last processed points instead of a `hasProcessed` flag to determine whether or not we should re-process a given set of points.
- Store point coords in state instead of pulling them out of the konva node positions. This makes moving a point a more explicit action in code.
- Add a `roundCoord` util to round the x and y values of a coordinate.
- Ensure we always re-process when $points changes.
