bufferedBitmap ans screen transition.

My watchface is drawing a complex graph in a bufferedBitmap to minimise the screen redraws.
When I switch from a widget back to my watchface, its slow because I have to render the full graph again.

Is there a way to use previous rendered bufferedBitmap to draw the screen quickly during the transition ?

jim_m_58 over 8 years ago

How slow is "slow"?

Things can be saved when the WF exits and be used when it starts in the Object Store/Application.Storage, but I don't think you can save the buffered bitmap (it's it will be noted in the API doc). So maybe save the data needed to redraw the graph without recalculating it.

But, that may not help. Consider the case where the WF saves the data, and the user starts a 1hr run, then comes back to the WF. The saved data would be 1hr old can could be stale, and you want to completely re-draw it anyway.

I'd probably look for ways to optimize drawing the graph. Not knowing what the graph is, that could be things like preloading resources, maybe only redrawing the graph if something has changed, maybe reducing the data points you use in the graph, etc.

phgerin over 8 years ago

Thank you Jim !

Well, no you can't save bitmap with application storage.
Its not really slow, but its slow enough to notice it.....maybe 1 second on a Fenix 5S.