Ruby Now Has an Animated Map Engine (Alpha Preview)

January 15, 2026

Building real-time, animated maps in pure Ruby — no JavaScript required.

A new class of maps for Ruby

Over the past weeks, we’ve been extending ruby-libgd and libgd-gis far beyond static image rendering. What started as a raster + GIS toolkit is now evolving into something much bigger:

An animated map engine, written entirely in Ruby.

This new engine allows Ruby applications to render basemaps, draw vector layers, place dynamic sprites, and generate frame-by-frame animations — all from the backend.

No browser. No WebGL. No JavaScript.

Just Ruby.

How animation works at the lowest level

At its core, the system is built on primitive frame rendering using ruby-libgd.

A simple animated object can be produced with nothing more than an image buffer and a loop:

			
gif = GD::Gif.new("bounce.gif")
60.times do
  img = GD::Image.new(W, H)
  # background
  black = GD::Color.rgb(0,0,0)
  img.filled_rectangle(0,0,W,H, black)
  # bounce against walls
  if x - r <= 0 || x + r >= W
    vx = -vx
  end
  if y - r <= 0 || y + r >= H
    vy = -vy
  end
  x += vx
  y += vy
  # color depends on speed
  speed = Math.sqrt(vx*vx + vy*vy)
  color = GD::Color.rgb(
    100 + speed * 20,
    180,
    255 - speed * 20
  )
  img.filled_ellipse(x, y, r*2, r*2, color)
  gif.add_frame(img, delay: 5)
end

		

This is the same model used for map animation — except instead of circles, we render geographic layers.

Each frame is a full GIS composition.

From pixels to geospatial animation

On top of this low-level renderer, libgd-gis adds geographic intelligence:

projections
layers
routes
basemaps
moving objects

A typical animated map frame loop looks like this:

			
frames.times do |i|
  t = i.to_f / (frames - 1)
  car_layer.data = [{ "geometry" => { "coordinates" => car.point_at(t) }}]
  plane_layer.data = [{ "geometry" => { "coordinates" => plane.point_at(t) }}]
  img = map.render_with_base
  draw_legend(img)
  gif.add_frame(img, delay: 5)
end 

		