I am working with Latitude / Longitude coordinates in a google map.
I have two lines :
- Line A : 48.31508162629726, -2.591741396838972 to 48.40216156645915, -2.2218462112093404
- Line B : 48.383816077371215, -2.274292940053768 to 48.66103546935337, -1.7066197241571377
I then use the following formula to find the point where they cross.
var XAsum = A.LngStart - A.LngEnd;
var XBsum = B.LngStart - B.LngEnd;
var YAsum = A.LatStart - A.LatEnd;
var YBsum = B.LatStart - B.LatEnd;
var LineDenominator = XAsum * YBsum - YAsum * XBsum;
if(LineDenominator == 0.0)
return false;
var a = A.LngStart * A.LatEnd - A.LatStart * A.LngEnd;
var b = B.LngStart * B.LatEnd - B.LatStart * B.LngEnd;
var x = (a * XBsum - b * XAsum) / LineDenominator;
var y = (a * YBsum - b * YAsum) / LineDenominator;
This tells me that the lines do indeed cross and returns the x and y values.
However, when I plot the returned point, it is offset (not much) from the real intersection.
Is there a better and just as fast algorithm I could use which will return me the correct intersection point ?
It needs to be fast as I am iterating over a large number of lines (~1000).
EDIT : Note this is giving me an error offset of around 7.5 meters