AI gen code to allow negative buffers

[balbionthebox]

This code, which works for the feature requested by Ken, needs to be double checked as it is fully AI generated.

When given a negative radius now creates a new smaller object compared to the original one, considering the radius absolute value.

This allows to create a raster buffer in a second step:

e.g. try in "Bilbao"

model each ecology:Forest earth:Region
	observing landcover:LandCoverType named lct
	using gis.features.extract(select = [lct is landcover:Forest]); 

thing Banana;

private model each Banana
	observing ecology:Forest earth:Region named frg
	using 
		im.geoprocessing.buffer(artifact = frg, radius = -50, subtract = false);
		
thing Buffer;
		
model presence of Buffer
	 observing 
	 presence of Banana named bana,
     presence of ecology:Forest earth:Region named regio
     set to [regio == true && bana == false]
     ;

[euskalhenriko]

The changes are aesthetic; it seems that the code has not been substantially modified.
These lines should make a difference but they are equal to the previous ones.
New:

// Apply buffer (positive = external, negative = internal)
IShape newShape = workingShape.buffer(bdistance);

Old:

IShape newShape = oshape.buffer(bdistance);

Try entering negative values into the actual code. If this doesn't work, we can check which changes are necessary.

[kbagstad]

It does work. Many thanks for your prompt attention to this! I'll make a note in quick tips that negative values for an inner buffer are also possible.

[balbionthebox]

NOTE to keep the handling of collapsed subjects.
The original code produces results pretending that the collapsed subjects still exist.