That depends on how you define "an area". Is it a rectangle, given the coords of two points of a diagonal? A triangle, given the coords of the three points? A circle, given the radius and coords of the center? An oval, given the coords of the center, max radius and min radius? A semicircle, given the radius, the coords of the center and the angle to cut the circle from? Or a polygon, given the coords of the points? (So polygon includes triangle too) This link may help you with circle, rectangle and polygon (IrregularShape) checking. https://github.com/PEMapModder/Small-ZC-Plugins/tree/master/CustomAreas/src/customareas/shape (see the isInside function)
