Allow static images without zooming

[jukkatupamaki]

These changes make the Ken Burns effect optional. If a clip does not specify the zoomDirection parameter, it renders a static image instead.

[mifi]

Thanks for the PR, but can't the same be achieved by setting scaleFactor to 0?

[jukkatupamaki]

Yes that is true but it is a bit counter intuitive. 😕 By looking at the json config, I’d expect it to not zoom in/out if I leave out both direction and amount. I guess I could have changed just the default factor from 1 to 0.

[mifi]

I agree it's a bit counter intuitive. I wanted the defaults to be opinionated and "feature rich". That's why also there is random background colors, random gradients and random transitions enabled by default. Maybe we can just make it so that if zoomDirection is anything else than 'in' or 'out', then zooming is also disabled?

[chapmanjacobd]

I agree the opinionated defaults are nice but it would be good to also have an unopinionated example template that people could use. Can we do something like

defaults: {
    layers: [ 
        { type: 'image', zoomDirection: 'none' }
    ]
},

So we don't need to specify it on each one?

[mifi]

I implemented this check now, so you can use zoomDirection: null or 'none' or anything else to disable. Thanks @tukkajukka