BRT Community

General Category => Discussion - EVE => Topic started by: rmand on November 01, 2023, 02:27:13 PM

Title: Clarification on scrolling
Post by: rmand on November 01, 2023, 02:27:13 PM
From what I have gathered scrolling on EVE is achieved by simply redrawing the list at a new position.  This works really well when scrolling images and lighter lists.

In our case, we're trying to implement a menu swipe and the screen (list) contains a lot of active elements. Just the SPI transfer of the list takes a bit of time; but this is fine if you're rendering the screen once as it loads.

When it comes to scrolling, however, I think we're limited by the SPI bandwidth and BT817's FIFO and ability to process the list.

Is there a way to tell the chip to "shift" an already loaded list? or a smoother way of accomplishing this?

tia

Title: Re: Clarification on scrolling
Post by: BRT Community on November 07, 2023, 04:51:46 PM
Hi,

For your scrolling, was it mainly for a whole page (e.g. if a menu fills the whole screen or to swipe between pages) or was it for just certain items on a page (for example the list of items in a menu area of the screen)?

One thing that may be useful in some cases is the VERTEX_TRANSLATE which allows you to add an offset to the subsequent Vertex calls. However, it may not always be the best solution,

Best Regards, BRT Community

Title: Re: Clarification on scrolling
Post by: rmand on November 09, 2023, 09:28:52 PM
Thanks for responding!

Yes.  We need the whole page slid over. For partial screen e.g. list of items it's easy to manage the animation.

I'll look into VERTTEX_TRANSLATE.  It'd be nice to be able wrap the entire page in it.