I'm hoping to find a way using GEOSwift to take a series of user's LatLngs, construct a linestring and buffer it to always be 30 meters wide regardless of the user's location. I feel like there must be an easier way than the path I'm going down and any help would be appreciated.
Background:
From what I can tell the buffer functions width parameter is currently defined in decimal degrees as my coordinate system is EPSG 4326, which makes calculating the width in meters difficult. I can get a rough estimation of meters per decimal degree for both longitude or latitude with the Haversine formula.
The problem I have is the series of points can move both latitudinally and longitudinally. So the buffer width I need in these cases lies somewhere between ThirtyMetersInLatDegrees and ThirtyMetersInLngDegrees. And in this case the width to supply to the buffer function becomes a weird approximation/ average of the user's overall longitudinal and latitudinal movement throughout the linestring related to ThirtyMetersInLngDegrees and ThirtyMetersInLatDegrees.
i.e. assuming ThirtyMetersInLngDegrees is the max:
ThirtyMetersInLatDegrees <= bufferWidth <= ThirtyMetersInLngDegrees
How can I better accomplish this?
Here's how I'm calculating meters per decimal degree:
//Earth’s radius
let R=6378137.0
let deviceLatitude = 37.535997
let OneMeterInLatDegrees = 1/R * (180/Double.pi)
let OneMeterInLngDegrees = 1/(R*cos(Double.pi*deviceLatitude/180)) * (180/Double.pi)
let ThirtyMetersInLatDegrees = 30 * latDegreesPerMeter
let ThirtyMetersInLngDegrees = 30 * lngDegreesPerMeter
