POLYEND doesn't throw an error when there are two vertices
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#477 POLYEND doesn't throw an error when there are two vertices
POLYEND has some logic to throw an error if the polygon has fewer than three vertices. However, due to a simple coding error, it does not throw an error if the polygon has two vertices. Instead, it creates an illegal polygon and renders nothing when POLYVIEW is run.
The bug has existed since at least MSWLogo 6.5b.
Steps to Reproduce:
PERSPECTIVE POLYSTART FD 100 RT 90 FD 100 POLYEND
What Happens:
There is no error. If you run POLYVIEW you see nothing.
Expected Result:
When POLYEND is run, FMSLogo displays an error message about a polygon having too view vertices.
Compare this behavior to what happens when you create a polygon with one vertex, as with:
PERSPECTIVE POLYSTART FD 100 RT 90 POLYEND
Compare this behavior to what happens when you create a polygon with three vertices, as with:
PERSPECTIVE POLYSTART FD 100 RT 90 FD 100 RT 90 FD 100 POLYEND POLYVIEW
I have committed a fix, which will be available in FMSLogo 7.0.