//Check hashmap for lines that are equivalent. Note that we need to check one epsilon above and below the actual slope
//since we're defining two lines as equivalent if they're within an epsilon of each other.
int CountEquivalentLines(Dictionary <Double, List <Line> > linesBySlope, Line line)
{
double key = Line.FloorToNearestEpsilon(line.Slope);
int count = CountEquivalentLines(linesBySlope[key], line);
count += linesBySlope.ContainsKey(key - Line.Epsilon)
? CountEquivalentLines(linesBySlope[key - Line.Epsilon], line)
: 0;
count += linesBySlope.ContainsKey(key + Line.Epsilon)
? CountEquivalentLines(linesBySlope[key + Line.Epsilon], line)
: 0;
return(count);
}
// insert line into hashmap
void InsertLine(Dictionary <Double, List <Line> > linesBySlope, Line line)
{
List <Line> lines;
double key = Line.FloorToNearestEpsilon(line.Slope);
if (!linesBySlope.ContainsKey(key))
{
lines = new List <Line>();
linesBySlope.Add(key, lines);
}
else
{
lines = linesBySlope[key];
}
lines.Add(line);
}