requires user interface to specify the depth, number of passes,
feed, and plunge feed, unfortunately.
[git-p4: depot-paths = "//depot/solvespace/": change = 2106]
breaks with the new path stuff, since circular holes really do have
to go ccw. So fix that.
[git-p4: depot-paths = "//depot/solvespace/": change = 2062]
also means that closed contours will get output as a single path
now, vs. one open path per Bezier segment before.
I've simplified the 2d/3d wireframe export targets somewhat; they
now support only Beziers, without an additional special case for
line segments. The performance penalty for that should not be worth
caring about, since that's infrequent.
And fix a memory leak in FindOuterFacesFrom(), fix ugly output of
filled triangles in PDF (because the line join style did bad things
on long skinny triangles), fix non-zero Z coordinates for exported
views or sections in DXF or STEP.
[git-p4: depot-paths = "//depot/solvespace/": change = 2061]
the same plumbing as the 2d vector output.
Also fix piecewise linear tolerance when the export scale factor is
not equal to one; have to scale the chord tol along with that.
[git-p4: depot-paths = "//depot/solvespace/": change = 2053]
formats, with the proper color and width. This may need a bit of
cleanup for stuff like the hidden line removal, which currently
loses the style.
Also fix a bug in the test for arcs of a circle. A second-order
Bezier with collinear control points really is an arc, but it's an
arc with infinite radius so stuff tends to blow up. So return false
for that one.
[git-p4: depot-paths = "//depot/solvespace/": change = 2030]