"Select Touching" misses some brushes

[ericwa]

System Information

TrenchBroom V2.0.0-RC4 on macOS
also reproduced on a build of release/v2.0.0 + open PR's.

Expected Behavior

"Select touching" should select all touching brushes. In this case the pipes should have been selected, but they weren't for some reason:

Steps to Reproduce

1. Get pritchard1-valve.map from Hard lines in shadows/dirtmap ericwa/ericw-tools#134

2. Copy and "paste at original position" the following brush:

// entity 0
{
"classname" "worldspawn"
// brush 0
{
( 784 -624 656 ) ( 5536 -624 672 ) ( 5536 -624 656 ) __TB_empty [ 1 0 0 -0 ] [ 0 0 -1 -0 ] -0 1 1
( 784 -208 656 ) ( 784 4672 672 ) ( 784 -208 672 ) __TB_empty [ 0 -1 0 -0 ] [ 0 0 -1 -0 ] -0 1 1
( 784 -208 -1792 ) ( 5536 4672 -1792 ) ( 784 4672 -1792 ) __TB_empty [ -1 0 0 -0 ] [ 0 -1 0 -0 ] -0 1 1
( 784 -208 1200 ) ( 5536 4672 1200 ) ( 5536 -208 1200 ) __TB_empty [ 1 0 0 -0 ] [ 0 -1 0 -0 ] -0 1 1
( 784 4672 656 ) ( 5536 4672 672 ) ( 784 4672 672 ) __TB_empty [ -1 0 0 -0 ] [ 0 0 -1 -0 ] -0 1 1
( 5536 -208 656 ) ( 5536 4672 672 ) ( 5536 4672 656 ) __TB_empty [ 0 1 0 -0 ] [ 0 0 -1 -0 ] -0 1 1
}
}

3. Use the "select touching command". Press delete to delete a large chunk of the map. There will be some pipes left over that should have been deleted:

[ericwa]

Reduced test case with one worldspawn brush:
touching.map.txt

Use the same cube as above for the "select touching" operation.

[ericwa]

I extracted it into a test case which I'll push in a second. Seems like Polyhedron<T,FP,VP>::polyhedronIntersectsPolyhedron is returning a wrong answer (false) when it should return true.
const V direction = crossed(lhsEdgeVec, rhsEdgeVec);
is almost a null vector:

(lldb) print direction
(V) $5 = {
  v = ([0] = 0, [1] = -0.00000001728767529129982, [2] = -0.00000000864383764564991)
}
(lldb) print lhsEdgeVec
(V) $6 = {
  v = ([0] = 4752, [1] = 0, [2] = 0)
}
(lldb) print rhsEdgeVec
(V) $7 = {
  v = ([0] = -320, [1] = -0.0000000000018189894035458565, [2] = 0.000000000003637978807091713)
}

[ericwa]

Fixed in 71804d4