On 1/16/2022 8:07 AM, Joe Weinpert wrote: > Was not sure what "closed" meant. In the world of polygons, "closed" means that the path comes back to finish at its start.  When you're representing a closed polygon as a list, the fact that there's a beginning and an end is kind of an unfortunate implementation artifact, because logically the "first" point immediately follows the "last".  A closed polygon is a loop with no true beginning and end. > If I understand, it now means to remove any and all end rows in the > array that match the very first row. Assuming that we're talking about a deduplicator... yes, in addition to removing all *other* points that duplicate the immediately previous point. https://github.com/revarbat/BOSL2/wiki/comparisons.scad#function-deduplicate has some examples. For completeness, though it's not directly relevant in this discussion, in a 3D mesh "closed" means that there are faces completely covering the object, that the "inside" is entirely on the inside.  If you're trying to build a cube, it is not "closed" until you have supplied all six faces.

The term "closed" here is a BOSL2 term, not a general OpenSCAD or modeling term, I think. It is meant to indicate that the sequence of points has no end, that the first and last point are adjacent. We are thinking that we may change "closed=true" to "wrap=true" in some cases. (And in other cases to "polygon=true", to distinguish a path with two endpoints from one that describes a polygon.) Does this seem more clear to you? On Sun, Jan 16, 2022 at 11:08 AM Joe Weinpert <joe.weinpert@gmail.com> wrote: > > Well, to me I am looking at a list as an array. Was not sure what "closed" meant. I am guessing now that it is something in the world of mesh. My ignorance of the OpenSCAD terminology will stay with me for a long time. I was expecting something like javaScript (not sure why). If I understand, it now means to remove any and all end rows in the array that match the very first row. > > > Joe Weinpert > (440) 796-7165 > joe.weinpert@gmail.com > > > > On Sat, Jan 15, 2022 at 7:11 PM Adrian Mariano <avm4@cornell.edu> wrote: >> >> Can you elaborate on what you are referring to (something in the BOSL2 >> docs?) that made you think that "equality" referred only the x >> coordinate? How could the docs be clarified to improve this? >> >> On Sat, Jan 15, 2022 at 6:46 PM Joe Weinpert <joe.weinpert@gmail.com> wrote: >> > >> > I will try that, too. However, The description of the "Closed" clause I read as being only based on the value of each value within the sub arrays being checked ... i.e. check only the X value and if it matches delete the row without needing to check the Y value. >> > >> > On Sat, Jan 15, 2022, 6:27 PM Adrian Mariano <avm4@cornell.edu> wrote: >> >> >> >> It occurs to me that if you're running deduplicate already when >> >> creating your point list that you should just add closed=true to >> >> deduplicate, and it will remove repeated points between the start and >> >> end as well. The BOSL2 deduplicate implementation considers points >> >> equal if they are closer than eps, which defaults to 1e-9. I don't >> >> think doing exact compares for floats is the best plan, though I guess >> >> it might work. (You could end up with some very tiny triangles in >> >> your model.) >> >> >> >> On Sat, Jan 15, 2022 at 5:40 PM Joe Weinpert <joe.weinpert@gmail.com> wrote: >> >> > >> >> > I am finding answers here, so it is appreciated. Will look deeper into the BOSL library as I go. Knowing what to look for is tough. >> >> > >> >> > On Sat, Jan 15, 2022, 5:22 PM Adrian Mariano <avm4@cornell.edu> wrote: >> >> >> >> >> >> Variables can only be set once. If you think you're setting one a >> >> >> second time it's actually in a nested scope and it will vanish once >> >> >> you leave the scope. With let() statements you can cascade scopes in >> >> >> a way that looks like you are redefining the variables, but each let >> >> >> opens a new scope. >> >> >> >> >> >> Looks like nophead has explained a way around this using the ? >> >> >> operator. You might also want to use BOSL2's cleanup_path() function, >> >> >> assuming your data is numeric. >> >> >> >> >> >> On Sat, Jan 15, 2022 at 5:09 PM Joe Weinpert <joe.weinpert@gmail.com> wrote: >> >> >> > >> >> >> > What am I missing here? >> >> >> > >> >> >> > I need to set a new array of points with the last index removed from the original array or the whole original array depending on if the last one in the original array equals the first one in the original array. >> >> >> > >> >> >> > Essentially: >> >> >> > >> >> >> > x = len( objPoints )-1; >> >> >> > if( str( objPoints[x] ) == str( objPoints[0] ) ){ >> >> >> > newPoints = list_remove( objPoints, x ); >> >> >> > }else{ >> >> >> > newPoints = objPoints; >> >> >> > } >> >> >> > echo( newPoints ); >> >> >> > >> >> >> > >> >> >> > So why isn't the newPoints variable recognized outside the IF statement? >> >> >> > >> >> >> > _______________________________________________ >> >> >> > OpenSCAD mailing list >> >> >> > To unsubscribe send an email to discuss-leave@lists.openscad.org >> >> >> _______________________________________________ >> >> >> OpenSCAD mailing list >> >> >> To unsubscribe send an email to discuss-leave@lists.openscad.org >> >> > >> >> > _______________________________________________ >> >> > OpenSCAD mailing list >> >> > To unsubscribe send an email to discuss-leave@lists.openscad.org >> >> _______________________________________________ >> >> OpenSCAD mailing list >> >> To unsubscribe send an email to discuss-leave@lists.openscad.org >> > >> > _______________________________________________ >> > OpenSCAD mailing list >> > To unsubscribe send an email to discuss-leave@lists.openscad.org >> _______________________________________________ >> OpenSCAD mailing list >> To unsubscribe send an email to discuss-leave@lists.openscad.org > > _______________________________________________ > OpenSCAD mailing list > To unsubscribe send an email to discuss-leave@lists.openscad.org