Giro: display copies of recorded routes

Reviewed September 6, 2026.

Giro keeps recorded coordinates and derives a smaller list for drawing. This lets rendering change without rewriting the journey.

Two passes

RouteSimplifier keeps the first point, retains intermediate coordinates that satisfy a minimum distance, and appends the last point. If too many remain, it samples that list at a stride. The defaults are four meters and 1,200 display points.

What survives

The archived input remains available. The returned list retains endpoints, but the stride pass can omit a bend. A lower point count is not automatically a better approximation.

What belongs elsewhere

GPS outlier rejection and map matching solve different problems. A display simplifier should not be described as correcting location history or guaranteeing a safe route. The app hands navigation off to map applications.

Sources

• app/Giro/RouteSimplifier.swift, base 2ef0f85
• Giro repository
• Project
• Synthetic route example