Dot Density map with Openlayer

[James Bond]

Hi, 

I'm trying to create a dot-density map with OL and GeoServer. I've a counties shape file and I'm creating a vector layer in OL with county shape file set as source for the vector layer. I need to show dots (based on data in our api) inside the county feature. According to this example, a coordinate is required to draw a point. I need to make sure that any coordinate I give is inside the county feature.

My question is if its possible with jsts to get all coordinates inside a feature. 

Thank you!