Reproject Sentinel 3 image with snappy

Hello.
I didn’t find where snappy questions are, therefore I write here.
I recently installed snappy and I’d like to use it to automatically use, through my python script, the SNAP functions optical->preprocessing->radiance-to-reflectance and raster->geometric operation->reprojection.
My first question is are those functions implemented in snappy?
I checked some topics like this Overview of snappy functions?, but it’s quite chaotic for me since there is a huge amount of information. Some refer to a jupyter notebook that I don’t even understand what it is.
Anyway, my second question is is there a direct link in github for the reprojection function? I already found the code of radiance to reflectance so I could implement it by myself, but I didn’t have the same luck with the reprojection one.
Thank you in advance.

The processors are all callable from snappy. For some other functions it is different.
That’s I’ve mentione a few minutes ago here:

The sticky post gives a general breif introduction and points to useful pages.

With the following snippets you get a list of operation you can invoke from snappy with GPF.

op_spi_it = GPF.getDefaultInstance().getOperatorSpiRegistry().getOperatorSpis().iterator()
while op_spi_it.hasNext():
    op_spi = op_spi_it.next()
    print("op_spi:", op_spi.getOperatorAlias())

In general all operations are invoked more or less the same:

GPF.createProduct(“OperatorAlias”, parameterMap, sourceProduct)

If you search for ‘GPF.createProduct’ in this forum you will find several examples which can help you.