Improve performance of trimmed(from:,to:) #192
Merged
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
So, I found the performance of the
LineString.trimmed(from:to:)
to be unusably slow and that it's caused by this distance calculation.Calculating the distance between coordinates
i
andi+1
can be done with a simple/cheapdistance(to:)
, but instead theLineString.distance(from:to:)
is used, which kills performance because it allowsfrom
/to
to not be on the line and has to calculate which line coordinate is closest usingclosestCoordinate(to:)
, a O(n) operation, which leavestrimmed(from:to:)
at a terrible O(n^2).Please let me know if I'm missing anything.