Fill tool in GraphTool doesn't work if fill point is too close to a boundary

[dlglin]

If the fill point in a GraphTool fill object is within half of the snapSize of a boundary, then the region does not get filled. See the MWE below.

If this is the expected behaviour then we should put a note in the POD about it.

DOCUMENT();

loadMacros('PGstandard.pl', 'PGML.pl', 'parserGraphTool.pl', 'PGcourse.pl');

$gt1 = GraphTool(
    "{line,solid,(0,0),(0,-1)},
    {fill,(-1/2,0)}"
);

$gt2 = GraphTool(
    "{line,solid,(0,0),(0,-1)},
    {fill,(-.5001,0)}"
);

$gt3 = GraphTool(
    "{line,solid,(0,0),(0,-1)},
    {fill,(-1/4,0)}"
)->with(snapSizeX => 1/2);

$gt4 = GraphTool(
    "{line,solid,(0,0),(0,-1)},
    {fill,(-.251,0)}"
)->with(snapSizeX => 1/2);

BEGIN_PGML
[@ $gt1->generateAnswerGraph() @]*

[@ $gt2->generateAnswerGraph() @]*

[@ $gt3->generateAnswerGraph() @]*

[@ $gt4->generateAnswerGraph() @]*
END_PGML

ENDDOCUMENT();