I literally just did the CirclevsCircle stuff this week, so it's possible I haven't flushed through a change I need to to make it work. I wouldn't worry about it for now.
The warnings are not failures as much as a running TODO list.
Upgrading to VS 2013 is on my todo list, but I haven't tackled it yet. I imagine it will make this stuff much easier.
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Basically:
Entering/Exiting - A forcefull collision, with the collider entering or exiting the collidee.
GlancingParallel - Two features (ie: vertex or edge) are rubbing against each other in such a way that they are neither entering nor exiting each other. Imagine one box sliding on top of another, for instance.
GlancingInside/Outside - Imagine throwing a ball up to the ceiling so that it *just* touches the ceiling and then falls back down. Here, *just* means it has 0 velocity when it touches. Inside/Outside indicates whether you're inside the polygon glancing against the boundary from the inside or outside the polygon glancing against the boundary from the outside.
Stationary - Means the two features are intersecting but not moving relative to each other. Basically if you had a GlancingParallel collision and froze the motion, it would be Stationary.
GlancingParallelEntering/Exiting - I don't think this will get returned by anything; it's mostly used internally.
FeaturesAligning - Usually means two polygons are
really deeply penetrating. Basically the interior side of one feature is colliding against the exterior side of another feature, and continuing on.
I need to play with it all some more. I might collapse some of the states, or rename them, or combine them, or add more. I don't have a good intuitive sense of what the different states really are for two colliding polygons. I originally thought I could get away with just entering/exiting states but I need more data than that when I process the results of the collision detection algorithm to feed it in to a useful format.
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In terms of visualizing, there isn't anything super convenient right now. If you were feeling adventurous you could see about generating animated SVGs from the test description. The SimplePolygon class already has something for spitting out SVG descriptions of the polygons, for instance, and there's a javascript library I'm using to allow the mouse to zoom and pan the image in the browser. See for instance Modules\Annulus\Annulus.UnitTests\CSG\StraightSkeletonBuilderTests.cs, around line 1160, where I set up a full SVG for a test. I haven't played with it at all but I think
SVG animation is possible. The advantage of SVG animation is that you can literally specify the angular velocity, position, linear velocity, etc. and update the elements' transforms from those, so it would be the easiest way to visualize what the input data is doing. Of course, it involves very webby programming, which I'm not all that knowledgeable about so I don't know how much help I could give. It's almost certainly worth the effort if you could do it.
There's also Annulus.Testbed, but whether you can get it to run or not is questionable. You'd have to manually copy the test input data to Modules\Annulus\Annulus.Testbed\Main.cs to get it to work. And I haven't done much proofing of the graphics stuff so I'm not sure what you'd have to have installed in terms of DirectX SDKs, etc., to make sure it would work.