Have you tried running simplifying the lines before rendering? Rendering 150k points is cool, but there aren't enough pixels to see that
level of detail.
another major reason for ditching it is that all the series must be x-value-coalesced, so it's impossible to remove/merge datapoints along any single x without incorrectly removing/merging them in an unrelated y.
since the path is drawn directly from the data without any intermediate data->path conversions & allocations, i dont think there will be a reasonable point at which general path simplification would provide a net positive.
i'm pretty sure dygraphs does some form of simplification which seems to render well, but overall it ends up slower (not necessarily due to this, but did not check). it was also written at a time when Canvas was not as fast as it is today, so maybe it made more sense back then.
One really simple idea: group points by their x pixel, connecting the max and min y values for each with a vertical line.
feel free to experiment, but i suspect that any workable solution is not going to be cheap enough and is likely to not be simple and high quality.
you must be able to simplify each data series as a stream (during the path drawing loop itself) rather than allocating another set of 3 x 50,000-element pixel offset arrays, which will eat up all the benefit very quickly.
im on a phone, but will look into it later, thanks!
if you want to open an issue in the repo to work on porting this to the lib for actual apples-to-apples comparison, that would be cool, too :)
I added code for gaps. The tight loop isn't disrupted that much; the number of interruptions is bounded by the x resolution.
added a placeholder issue https://github.com/leeoniya/uPlot/issues/15