Transition to terra

[see24]

Start a new branch to work on using terra instead of raster. Continue supporting raster inputs though. Look into whether terra can do the things we currently do with stars to see if we can remove that dependency. I will document any challenges that come up here as a reference for repeating the process in other packages

The terra website has a table showing new function names and raster equivalents and highlights differences in behaviour https://rspatial.github.io/terra/reference/terra-package.html#xxv-new-method-names-1

[see24]

Functions that seem different but not included in table above

raster	terra	behaviour change
clump	patches	raster used 0 and NA as background default in terra is just NA
unique	unique	Now returns a data.frame (in both raster and terra) used to be a vector?
rasterToPoints	as.points	No longer has option to use a function
as.matrix	as.matrix	Returns 1 column per layer unless wide = TRUE

[see24]

Note that terra::vect which converts sf objects to SpatVector will drop additional geometry types if the input is a geometry collection. See terra issue

[see24]

Needed to keep sp and raster as dependencies in the package in order to deal with sp and raster inputs. Also kept the demoScen rasters as Raster* objects because terra SpatRasters cannot be stored in .rds files without first wrapping them which would then need to be unwrapped before using

[see24]

Doing something like rast[is.na(other_rast)] <- NA worked with RasterLayers if they had resolutions that fit together even if they were different but doesn't work for terra SpatRaster unless the resolutions are the same

[see24]

See this discussion from Alex about setting options if I come here looking for that https://for-cast.zulipchat.com/#narrow/stream/296360-r-help/topic/terra/near/322152043