geojs: Version 0.6.0

Release Notes New features and API additions

• Completely new tile layer class that moves formally GL specific code into core
  • Maps no longer require GL or even a base layer
  • Support for SVG and HTML rendering for tile layers
  • Support for arbitrary PROJ4 projection strings
  • Support wrapping tiles both horizontally and vertically for periodic images
  • Tiles can be an arbitrarily sized rectangle
  • Hooks for dynamically generated tiles rather than just static images
  • The definition of "zoom level" is now consistent with the use in other libraries
• New camera class used to keep track of the visible area and world to image space conversions
• General support for image pyramids through the tile layer (including medical imaging)
• Choropleth feature type
• New API for widgets
• New example showing off the features available for tile layers
• GeoJSON reader now supports Polygon and Multipolygon geometries
• Layers can now be reordered dynamically
• Added a new mouse event (click) that detects mouse clicks on the map canvas
• The map interactor can be disabled temporarily to cede control of the mouse and keyboard events to external handlers
• Support for subdomains in tile url template strings
• Opacity controls are now supported by all layer types
• Map "origin" parameter provides a fixed offset for world coordinates to support higher precision at high zoom levels
• New map option (clampZoom) to limit zoom levels to a given range
• New osmLayer option (tileRounding) to control which tiles are loaded at non-integer zoom levels

API changes

• Web mercator (EPSG:3857) coordinates are now in units of meters rather than degrees
• Lower resolution tiles are loaded before high resolution tiles
  • Creates the perception of faster load times
  • Greatly reduces the occurrence of background visibility while tiles load
• Removed the per-layer geographic projection attribute (layer.gcs) that was never fully implemented
  • Every layer is now expected to render in the map's world coordinate system
  • Feature layers can define a "local" coordinate system that is used internally
  • Tile layers have an additional coordinate system defined for each displayable zoom level
• Removed geo.mercator in favor of a generic projection class based on PROJ4
• Tile URL template strings now use the more common curly brackets ({x}) rather than angle brackets (<x>)
• Nearly all of the internals of the osmLayer

Performance

• A tile fetch queue now prioritizes downloaded tiles by what is currently in view
• Mouse event handlers are now throttled to fire at most every 30 ms
• Compiled GL shaders are now cached and shared between features
• Configurable tile cache size

Testing

• A new library of "mocked" classes has been started to mock interfaces between the classes inside unit tests.
• All new core classes have unittest coverage over 80% and many more classes now have coverage over 50%

File Cov File Cov File Cov event.js 100.0% tileLayer.js 96.2% mapInteractor.js 79.7% osmLayer.js 100.0% tile.js 96.1% renderer.js 71.4% tileCache.js 100.0% object.js 90.4% layer.js 70.8% timestamp.js 100.0% sceneObject.js 87.3% featureLayer.js 69.0% version.js 100.0% planeFeature.js 87.0% init.js 66.3% fetchQueue.js 100.0% imageTile.js 81.8% map.js 55.7% camera.js 97.7% Infrastructure and building

• Continuous coverage reporting of unit tests submitted to CDash
• VGL submodule removed in favor of inclusion via bower
• Support for installing as the root user
• Data used for testing and examples are now hosted at data.kitware.com
• The library is no longer built automatically after npm install to fix downstream build problems.

Bug fixes

• Setting camera bounds now uses the correct coordinate system
• GeoJSON polygon features no longer rendered as lines
• Discrete zoom now works with touch-like devices
• The planeFeature now handles coordinate transformations
• Rendering operations (such as loading new tiles) now occur during map navigation and transition events

Known issues

• Several performance problems have been exposed by rendering new tiles during map navigations
  • Many garbage collections occur during mouse handlers due to excessive memory allocations
  • Shader programs are not shared among tiles so they need to be linked for each tile

Contributors

• @aashish24
• @danlamanna
• @dcjohnston
• @jbeezley
• @manthey

Huge thanks to all of the contributers, and the many others who tested, created issues, and gave feedback during the development of this release.