Speed up of custom grid

[Peter Rehani]

Hi all,

I am designing a multi-view EKG tool that requires a custom grid: I have the entire thing contained within a DockArea for the easiest customization, and need to generate a few thousands lines to represent the grid lines as the user moves around the graph (top graph contains a static plot on top with a LinearRegionItem that updates the view on the bottom as it's dragged around). The problem is poor performance whenever the LinearRegionItem is dragged around and the bottom plot updates it's view. I have tried drawing my own lines as basic plots (just vertical and horizontal lines) as well as InfiniteLines, which is what I'm using right now. 

The data is a 2D array that represents changes in electrical pulses over a certain time sequence: I have the exact spacing that I need relative to the number of indexes that pass(I.e. I should have a line on say every 5th point). it just needs to be a bit more responsive than the 2-3 second delay between dragging and actually getting an output. 

Here's an example of what it would eventually hopefully look like: 

And here is what it looks like currently (attached, can't upload for some reason). The same style of grid would be applied to the bottom graph as well. 

I thought about trying to write it as an OpenGL plot that has a locked view (so you couldn't move around in Z) and then just keep it there as the graph expands. Any thoughts? I'm not sure if this post from 2013 was ever updated https://groups.google.com/forum/#!topic/pyqtgraph/5FyqefEm424. 

Thanks for any help you all can provide! 

Peter