Add a feature - Line length

I use the routine below in my tool JLG.Dimension (http://perso.orange.fr/jlg.outils) to calculate the length of a Bezier curve.<br />This is my little contribution to this discussion. To obtain the length as a string, you have to use a routine to convert a AIReal number into a string.<br />I hope this will help somebody.<br /><br />extern void BezierLength(AIArtHandle *path, short unit, AIReal scale, char BezierlengthText[])<br /> {//Calculate in BezierlengthText the total length of the Bezier curve (path). The result is a string.<br /> //If unit is 0 the length will be mm, 1 cm, 2 inches, 3 points, 4 picas and 5 for meters. <br /> AIErr error=kNoErr;<br /> long i, j;<br /> short pathCount, NtS;//NtS for number to string.<br /> AIBoolean IsClosed;<br /> AIRealBezier PtBezier;<br /> AIPathSegment Pt1, Pt2;<br /> //At the beginning, the length is zero.<br /> AIReal LengthOfBezier=0.0;<br /> <br /><br /> error = sPath->GetPathSegmentCount(*path, &pathCount );<br /> //If the path analyzed is closed, it will be necessary to add the length of the last part of the Bezier curve. <br /> error=sPath->GetPathClosed(*path, &IsClosed);<br /><br /> for(j=0;j<pathCount-1;j++)<br /> {//One point and the next point.<br /> error = sPath->GetPathSegments( *path, j, 1, &Pt1);<br /> error = sPath->GetPathSegments( *path, j+1, 1, &Pt2);<br /><br /> PtBezier.p0.h=Pt1.p.h;<br /> PtBezier.p0.v=Pt1.p.v;<br /> <br /> PtBezier.p1.h=Pt1.out.h;<br /> PtBezier.p1.v=Pt1.out.v;<br /><br /> PtBezier.p2.h=Pt2.in.h;<br /> PtBezier.p2.v=Pt2.in.v;<br /><br /> PtBezier.p3.h=Pt2.p.h;<br /> PtBezier.p3.v=Pt2.p.v;<br /><br /> LengthOfBezier+=sBezier->Length(&PtBezier, 1.0);<br /> }<br /><br /> if(IsClosed)<br /> {//The path is closed, we must calculate the length of the last segment (point 0 and point pathCount-1).<br /> error = sPath->GetPathSegments( *path, 0, 1, &Pt1);<br /> error = sPath->GetPathSegments( *path, pathCount-1, 1, &Pt2);<br /><br /> PtBezier.p0.h=Pt1.p.h;<br /> PtBezier.p0.v=Pt1.p.v;<br /><br /> PtBezier.p1.h=Pt1.in.h;<br /> PtBezier.p1.v=Pt1.in.v;<br /><br /> PtBezier.p2.h=Pt2.out.h;<br /> PtBezier.p2.v=Pt2.out.v;<br /><br /> PtBezier.p3.h=Pt2.p.h;<br /> PtBezier.p3.v=Pt2.p.v; <br /> LengthOfBezier+=sBezier->Length(&PtBezier, 1.0);<br /> }<br /><br /> //At this moment, LengthOfBezier contains the total length of the curve but the unit used is the point.<br /> switch(unit)<br /> {case 0://millimeters.<br /> LengthOfBezier=LengthOfBezier* 25.4 / 72.0 / scale;<br /> //Transform the length into a string.<br /> NtS=NumberToString(LengthOfBezier, BezierlengthText);<br /> //Add the unit.<br /> std::strcat(BezierlengthText, " mm");<br /> break;<br /> case 1://centimeters.<br /> LengthOfBezier=LengthOfBezier* 2.54 / 72.0/ scale;<br /> //Transform the length into a string.<br /> NtS=NumberToString(LengthOfBezier, BezierlengthText);<br /> //Add the unit.<br /> std::strcat(BezierlengthText, " cm");<br /> break;<br /> case 2://Inches.<br /> LengthOfBezier=LengthOfBezier/ 72.0 / scale;<br /> //Transform the length into a string.<br /> NtS=NumberToString(LengthOfBezier, BezierlengthText);<br /> //Add the unit.<br /> std::strcat(BezierlengthText, " in");<br /> break;<br /> case 3://Points.<br /> LengthOfBezier=LengthOfBezier/ scale;<br /> //Transform the length into a string.<br /> NtS=NumberToString(LengthOfBezier, BezierlengthText);<br /> //Add the unit.<br /> std::strcat(BezierlengthText, " pt");<br /> break;<br /> case 4://Picas.<br /> LengthOfBezier=LengthOfBezier/ 12.0/ scale;<br /> //Transform the length into a string.<br /> NtS=NumberToString(LengthOfBezier, BezierlengthText);<br /> //Add the unit.<br /> std::strcat(BezierlengthText, " pi");<br /> break;<br /> case 5://Meters.<br /> LengthOfBezier=LengthOfBezier * 0.0254 / 72.0 / scale;<br /> //Transform the length into a string.<br /> NtS=NumberToString(LengthOfBezier, BezierlengthText);<br /> //Add the unit.<br /> std::strcat(BezierlengthText, " m");<br /> break;<br /> default:<br /> break;<br /> }<br /> }<br /><br />JLG.

The AIPathSuite has function GetPathLength() that will get you the length of any path in points. Just pass it the handle of the line and you'll get your length value back. If you want that value in something other than points you'll have to convert it from points to whatever. That part you'll have to do yourself I think, but then there are well known conversion values for all the document units Illustrator uses.

Could you please explain better the function you are talking about? I don't quite understand how to get there. I'm having the same issue, I need to find out the length of a line. I was told that exporting the illustrator file to autocad, would do the trick, but I'm having problems doing it from CS3. If tehre is a way to find the lenght in Illustrator, it would be great!
Thanks,

If you're just trying to calculate that value in page units, there's a function AIPathSuite::GetPathLength() that should give you the length in *points*. You'll have to convert that to whatever units you want that in (be it inches, millimeters, centimeters, etc.). From what I remember, this should work for bezier lines as well.

If that doesn't work for some reason, I can point you to some example code that would let you do that yourself.

Not sure your understanding what I am asking for. Example is if you have a circle. what is the length of the line that makes up the circle.

I'm not quite sure what you're asking, but at least part of it sounds like you're wondering if you can display the length of a path in the Info window. If that's what you're asking, no, that's not possible. Nothing stops you from creating your own small palette to display such information though.

As for constraining the ability to edit parts of a path, no, you can't do that either. You might be able to construct a custom art type that let you do that, but it wouldn't be considered path art by Illustrator. If that's okay though, you might check out the AIPluginGroup suite.

> Would it be possible to add some sort of conversion tool that
> allows someone to take full illustrations a scale them to
> architectural scales. but does not affect the scaling of the
> illustration. some sort of window that has preset scale
> measurements.

Again, I'm not quite sure I follow. It kind of sounds like the work we do with MAPublisher, at least a little. If so, I'm guessing 'yes', but I'm not 100% sure since I don't quite understand what you're trying to do.