guidance-sim
v0.1.7
Published
Creates Mapbox Directions API guidance simulations using Mapbox GL JS
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guidance-sim
A project to simulate guidance routes using Mapbox GL JS from Mapbox Directions API responses.
Simulating a Mapbox Directions Guidance Route
var simulate = require('guidance-sim').simulate;
var configuration = require('./configuration.json');
var map = new mapboxgl.Map({
// desired map options
});
map.on('style.load', function () {
simulate(map, configuration);
});
Parameters
map
Object Mapbox GL map objectconfig
Object Configuration parameters, which include the following:
| parameter | required | type | default value | notes |
| --- | --- | --- | --- | --- |
| style
| Yes | String | mapbox://styles/mapbox/streets-v8
| Style ID provided by Mapbox Studio |
| route
| Yes | Object | --- | Mapbox Directions v4 or v5 API response |
| spacing
| No | String | constant
| constant
assumes a constant speed throughout playbackacceldecel
assumes an average speed per route step |
| zoom
| Yes | Number | 17
| If spacing
:constant
- zoom when not maneuveringIf spacing
:acceldecel
- zoom at 30mph |
| pitch
| Yes | Number | 45
| Pitch when not maneuvering |
| timestamp
| Yes | String | 00h00m00s
| Route simulation playback start time |
| speed
| Yes | String | 1x
| Route simulation playback speed |
| maneuvers
| Yes | Object | --- | Specifies desired buffer
(miles), zoom
, and pitch
for each maneuver |
The maneuvers
configuration parameter provides the simulator alternative map parameters when approaching and exiting a maneuver. The following configuration will ease sinusoidally from a pitch of 40° to 35° and zoom of 17 to 17.5 beginning 0.10 miles away from any turns, and ease back to the default values over 0.10 miles afterwards:
{
'zoom': 17,
'pitch': 40,
'maneuvers': [
{
"type": [
"turn right",
"turn left"
],
"buffer": 0.10,
"zoom": 17.5,
"pitch": 35
}
]
}
Example
npm start
# --> http://localhost:9966/
Creating a Configuration File
npm run configure
This script generates a starter configuration file for running a simulation. You will be prompted to provide inputs for parameters. Default parameters, presented in magenta text, will be automatically configured if you press `[ENTER]`` without specifying a value.
If there are errors, the script will print the first error it encountered. If there are no errors, a configuration file should be created at the specified filepath (i.e., first input provided).
Additional Notes
A maneuver
array will be automatically added to your configuration file. Please see the explanation above for maneuver object specifications.
For Directions v5 API responses, maneuvers have an additional modifiers
field. If a maneuver type
is specified but no modifiers
, it is assumed that the rule should be applied to all modifier
values. The exception to this is if a modifier
is specified for the same type
in another maneuver object. In this scenario, the more specific configuration takes precendence.
Validating a Configuration File
npm run validate
This script validates the configuration file. You will be prompted to provide the filepath of the file you'd like to validate. The default directory is the main directory.
If there are errors, the script will print the first error it encounters. If there are no errors, the script will print the JSON-formatted configuration file contents back into the terminal.
Seeking to a Different Point in the Simulation
This function runs the Emitter.stepsTaken function from guidance-replay using the start time determined by the user in the configuration file.
var Emitter = require('guidance-replay').Emitter;
var route = require('guidance-replay').route;
var stepsTaken = require('guidance-sim').stepsTaken;
var configuration = require('./configuration.json');
var emitter = new Emitter(route(configuration.route), 1000);
var seek = 10000 // desired seek time in milliseconds
stepsTaken(emitter, seek);
Parameters
emitter
Object An event emitter object coming off theEmitter
function inguidance-replay
scrub
Number Desired start time in milliseconds.
Adjusting Simulation Speed
This function clears the current interval and reinitializes a new interval using a new speed value.
var setSpeed = require('guidance-sim').setSpeed;
var map = new mapboxgl.Map({
// desired map options
});
map.on('style.load', function () {
var response = simulate(map, configuration);
response.on('update', function(data) {
var newSpeed = 500;
response.interval = setSpeed(response, response.interval, newSpeed, data.options.frequency);
})
});
Parameters
response
Object An EventEmitter objectinterval
Number An interval IDspeed
Number The duration in milliseconds over which to ease the map to the new locationoptions
Object Map options from initialization; seesimulate.js
L62:71 for more information
Test
npm test