7.0 KiB
Developer guide
Getting started
You will first need:
- Standard dependencies:
bash
,curl
,unzip
,gunzip
- Rust, at least 1.43. https://www.rust-lang.org/tools/install
One-time setup:
-
Download the repository:
git clone https://github.com/dabreegster/abstreet.git
-
Grab the minimal amount of data to get started:
./data/grab_minimal_seed_data.sh
. -
Run the game:
cd game; cargo run --release
Development tips
- Compile faster by just doing
cargo run
. The executable will have debug stack traces and run more slowly. You can docargo run --release
to build in optimized release mode; compilation will be slower, but the executable much faster. - Some in-game features are turned off by default or don't have a normal menu to
access them. The list:
- To toggle developer mode: press Control+S in game, or
cargo run -- --dev
- To warp to an object by numeric ID: press Control+j
- To enter debug mode with all sorts of goodies: press Control+D
- To toggle developer mode: press Control+S in game, or
- You can start the game in different modes using flags:
cargo run -- --dev ../data/system/maps/downtown.bin
starts on a particular mapcargo run ../data/system/scenarios/caphill/weekday.bin
starts with a scenario (which is tied to a certain map)cargo run -- --challenge=trafficsig/tut2
starts on a particular challenge. See the list of aliases by passing in a bad value here.cargo run ../data/player/saves/montlake/no_edits_unnamed/00h00m20.3s.bin
restores an exact simulation state. Savestates are found in debug mode (Control+D) -- they're probably confusing for the normal player experience, so they're hidden for now.cargo run -- --tutorial=12
starts somewhere in the tutorial- Adding
--edits='name of edits'
starts with edits applied to the map.
- All code is automatically formatted using
https://github.com/rust-lang/rustfmt; please run
cargo +nightly fmt
before sending a PR. (You have to install the nightly toolchain just for fmt) - More random notes here
Building map data
You can skip this section if you're just touching code in game
, ezgui
, and
sim
.
You have two options: you can seed some of the intermediate data by running
./data/grab_all_seed_data.sh
(downloads ~1GB, expands to ~5GB), or you can
build everything totally from scratch by running
./import.sh --raw --map --scenario
. This takes a while.
You'll need some extra dependencies:
osmconvert
: See https://wiki.openstreetmap.org/wiki/Osmconvert#Downloadlibgdal-dev
: See https://gdal.org/ if your OS package manager doesn't have this
You can rerun specific stages of the importer:
- If you're modifying the initial OSM data -> RawMap conversion in
convert_osm
, you need./import.sh --raw --map
. - If you're modifying
map_model
but not the OSM -> RawMap conversion, then you just need./import.sh --map
. - By default, all maps are regenerated. You can also specify a single map:
./import.sh --map downtown
.
Understanding stuff
The docs listed at https://github.com/dabreegster/abstreet#documentation-for-developers explain things like map importing and how the traffic simulation works.
Code organization
If you're going to dig into the code, it helps to know what all the crates are.
The most interesting crates are map_model
, sim
, and game
.
Constructing the map:
convert_osm
: extract useful data from OpenStreetMap and other data sources, emit intermediate map formatgtfs
: simple library to just extract coordinates of bus stopskml
: extract shapes from KML shapefilesmap_model
: the final representation of the map, also conversion from the intermediate map format into the final formatmap_editor
: GUI for modifying geometry of maps and creating maps from scratchimporter
: tool to run the entire import pipelineupdater
: tool to download/upload large files used in the import pipeline
Traffic simulation:
sim
: all of the agent-based simulation logicheadless
: tool to run a simulation without any visualization
Graphics:
game
: the GUI and main gameplayezgui
: a GUI and 2D OpenGL rendering library, using glium + winit + glutin
Common utilities:
abstutil
: a grab-bag of IO helpers, timing and logging utilities, etcgeom
: types for GPS and map-space points, lines, angles, polylines, polygons, circles, durations, speeds
Example guide for implementing a new feature
A/B Street's transit modeling only includes buses as of September 2019. If you wanted to start modeling light rail, you'd have to touch many layers of the code. This is a nice, hefty starter project to understand how everything works. For now, this is just an initial list of considerations -- I haven't designed or implemented this yet.
Poking around the .osm extracts in data/input/seattle/osm/
, you'll see a
promising relation with route = light_rail
. The relation points to individual
points (nodes) as stops, and segments of the track (ways). These need to be
represented in the initial version of the map, RawMap
, and the final version,
Map
. Stations probably coincide with existing buildings, and tracks could
probably be modeled as a special type of road. To remember the order of stations
and group everything, there's already a notion of bus route from the gtfs
crate that probably works. The convert_osm
crate is the place to extract this
new data from OSM. It might be worth thinking about how the light rail line gets
clipped, since most maps won't include all of the stations -- should those maps
just terminate trains at the stations, or should trains go to and from the map
border?
Then there are some rendering questions. How should special buildings that act as light rail stations be displayed? What about the track between stations, and how to draw trains moving on the track? The track is sometimes underground, sometimes at-grade with the road (like near Colombia City -- there it even has to somehow be a part of the existing intersections!), and sometimes over the road. How to draw it without being really visually noisy with existing stuff on the ground? Should trains between stations even be drawn at all, or should hovering over stations show some kind of ETA?
For modeling the movement of the trains along the track, I'd actually recommend
using the existing driving model. Tracks can be a new LaneType
(that gets
rendered as nice train tracks, probably), and trains can be a new VehicleType
.
This way, trains queueing happens for free. There's even existing logic to make
buses wait at bus stops and load passengers; maybe that should be extended to
load passengers from a building? How should passengers walking to the platform
be modeled and rendered -- it takes a few minutes sometimes!
Finally, you'll need to figure out how to make some trips incorporate light rail. Pedestrian trips have the option to use transit or not -- if light rail is modeled properly, it hopefully fits into the existing transit pathfinding and everything, so it'll just naturally happen.