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Elzar

Elzar Logo

"BAM!"

Elzar is a Python compiler that turns declarative style definitions into Mapbox GL style JSON, with native Go bindings for sprite generation.

It powers the map styles served by Woosmap.

Features

Declarative style tree

Define styles using dot-separated selectors (road.highway.motorway) that inherit from their parents. Change a color at road.highway and every child road type picks it up.

Style Tree

SDF sprite generation

Generate recolorable sprite sheets from SVG icons using a Go-native bin-packer. Icons use SDF rendering so icon-color and icon-halo-color work at runtime — including a dual-color trick for two-tone icons like road shields.

Sprite Generation

Style diff

Compare two style JSONs at the property level — see exactly which paint/layout/filter values changed, not just which layers were added or removed.

Style Diff

Multiple variants

Streets classic, satellite hybrid, and next-gen styles share the same generator and source data, with per-variant color palettes and layer configs.

Fully typed

Strict mypy, Pydantic v2 models for the entire Mapbox GL spec, zero Any types.

Quick start

# Install
make env

# Build native sprite library
make lib

# Generate the classic streets style
python -m map_style generate --style=streets -o style/streets_classic.json

# Generate with sprite sheet
python -m map_style generate --style=streets -o style/streets.json --generate-sprite

# Compare two styles
python -m map_style diff style/streets.json style/streets_classic.json

Getting started

Project structure

Package Description
map_style/generator/ Core rendering engine — style tree, layer renderer, Mapbox GL types, sprite bindings
map_style/streets_classic/ Classic streets style definition
map_style/streets_satellite/ Satellite hybrid style
map_style/streets_next/ Next-gen style (WIP)
map_style/diff.py Structural style comparator
sprite/ Go sprite generator (compiled to ctypes shared lib)

Next steps