workplanes. And fix up our polygon normals, so that everything gets
shaded correctly (and so that later we can generate our STL files
with correct normals).
[git-p4: depot-paths = "//depot/solvespace/": change = 1706]
faces of the polyhedron. And shade the faces when I draw them, and
fix up our projection matrix so that the depth testing works
properly.
[git-p4: depot-paths = "//depot/solvespace/": change = 1703]
issues, when the points are not all in the same coordinate system.
All painful, of course. Also add continuous line drawing, and
auto-constraining of line segments as I draw.
[git-p4: depot-paths = "//depot/solvespace/": change = 1683]
Jonathan Westhues