google maps - Given two point's latitude and longitude, computing coordinates of point in between -

google maps - Given two point's latitude and longitude, computing coordinates of point in between -

i'm trying generate annotations on map. currently, i'm using openstreetmap query general. have 2 end points on map , corpus of few selected points highlight.

the 2 endpoints given in form lat, long

<walksteps> <distance>9.742464221826811</distance> <streetname>5th st nw</streetname> <absolutedirection>east</absolutedirection> <stayon>false</stayon> <bogusname>false</bogusname> <lon>-84.3937361115149</lon> <lat>33.77692965678444</lat> <elevation/> </walksteps> <walksteps> <distance>508.2608917548245</distance> <relativedirection>left</relativedirection> <streetname>fowler st nw</streetname> <absolutedirection>north</absolutedirection> <stayon>false</stayon> <bogusname>false</bogusname> <lon>-84.39363494600667</lon> <lat>33.77692904176358</lat> <elevation/> </walksteps>

my aim highlight points on map, nowadays in corpus , lie in line connecting these 2 points.

how can go querying corpus same? annotating on map given lat, lng not issue

rounding errors prevent straight doing want. should doing instead determining great-circle path between 2 end points , highlighting members of corpus within distance of great circle route. known cross-track distance or cross-track error. formulas computing cross-track distance can found @ 1 of standard reference sites geospatial equations there others well.. problem becomes 1 of searching points in corpus close plenty great circle path between 2 end points.

google-maps math maps mapping latitude-longitude