Cómo dibujar rutas en mapas usando polilíneas en Jetpack Compose

Learning how to draw routes on a map using polylines is an essential skill when developing map applications using Jetpack Compose. Polylines allow us to visually represent specific routes or paths on a map, helping us to show path, directions or location tracking in a clear and effective way.

What do you need to create a polyline in Jetpack Compose?

A polyline is a series of connected line segments that require at least two points to be visible on a map. To create one in Jetpack Compose, you need the following:

• Two or more coordinate points (latitude and longitude).
• A specific Composable component called Polyline.
• Define attributes such as color andjoint type between segments.

How to add a section for polylines in your code?

To implement the logic and presentation of polylines, create a separate section or function inside the map folder. For example:

@Composablefun PolylinesSection(modifier: Modifier)  {  val latitudeLongitudeArray  = listOf(/* coordinates here */)  Polyline(    points  = latitudeLongitudeArray,    color  = Color.Blue,    jointType  = JointType.Bevel   )}

Each polyline needs at least two coordinates; a single one will not produce visual results on the map.

What is the role of the jointType parameter?

The option called jointType determines how the corners where two line segments connect will be visually joined, and there are different types:

• Round: produces rounded corners.
• Bevel: produces softer, more visually appealing corners.

The option you select will influence the aesthetics and visual perception of the path drawn in your application.

How to efficiently group coordinates in pairs to draw individual sections?

An effective strategy for rendering long, complex polylines is to group adjacent pairs of coordinates using the zipWithNext function. This creates manageable discrete subsegments that improve visual performance by rendering small sections of the line at a time:

val newArray  = latitudeLongitudeArray.zipWithNext()newArray.forEach  { pair ->  Polyline(    points  = listOf(pair.first, pair.second),    color  = Color.Blue,    jointType  = JointType.Bevel   )}

Visually, this helps to optimize rendering in interfaces with Jetpack Compose and makes it easier to observe specific changes within long paths or traces.

Why is it necessary to adjust the zoom level?

The polylines will depend on the zoom level of the map. To clearly visualize lines or routes, it is essential to manually adjust the zoom, especially when the implementation does not yet have automatic features for such a task.

In the next steps, you will learn how to automate this zoom adjustment and provide a smoother experience for your application users.