v0.11.0

Enhancements

• 10% reduction in minified + gzipped bundle size
• 25% faster label collision, as measured on a complex label scene (Bubble Wrap central London at z17) #440
• New placement strategies for improved cartographic symbols including road shields and one-way street arrows #409 #441
  • placement parameter to specify how points-based styles should be applied to line or polygon features:
    • placement: vertex: place points at line/polygon ring vertices (default and previous library behavior)
    • placement: midpoint: places points at line/polygon ring segment midpoints (better for road shields, to avoid ambiguous intersections such as highway interchanges)
    • placement: spaced: places points along a line/polygon ring at fixed intervals, useful for symbols like one-way street arrows where consistent spacing is desirable
      • Spacing defined in pixels with placement_spacing parameter; defaults to 80px, also accepts zoom stops or JS functions
    • placement: centroid: places points at polygon outer ring centroid
      • Only applicable for polygons (supersedes previous centroid: true parameter)
  • Additional parameters for placement values of midpoint and spaced:
    • placement_min_length_ratio parameter specifies the minimum line segment length as a ratio to the point being placed
      • Can be used to tune the number of symbols such as road shields up (with lower values) or down (with higher values), and avoid undesirable cases where a point obscures the underlying line segment
      • placement_min_length_ratio defaults to 1, requiring line segment to be at least as long as the point itself
      • See #441 for more examples
    • tile_edges parameter indicates whether points should be placed along tile boundaries (usually undesirable)
      • Applies same logic as lines styles.
      • tile_edges defaults to false.
• Enable repeat behavior (repeat_distance and repeat_group parameters) for points-based styles
  • Separate repeat_distance values can apply to a points-based draw group with an attached text. The former, on the "parent" point, determines how often any object of that type may repeat, while the latter, on the "child" text, determines how often an object with that specific text may repeat.
    • Example: one may wish for road shields generally to appear within 80px of one another, while requiring that a specific shield for the same highway only repeat every 200px

      shields:
        repeat_distance: 80px # any given shield can appear within 80px of any other shield
        ...
        text:
          repeat_distance: 200px # shields with the same text must appear at least 200px apart

• Allow scene import values to be JS objects 654b29a
  • Allows for scene properties to be overridden at initial load time, without need to hook into Tangram events or update scene after load
  • Example of this pattern, setting English language preference and enabling transit overlay on Mapzen's Bubble Wrap style at load time:

    scene.load({
      import: [
        'https://mapzen.com/carto/bubble-wrap-style/5/bubble-wrap.yaml',
        { global: { ux_language: 'en', sdk_transit_overlay: true } }
      ]
    });

• Adds smoothly animated double-click zoom via Leaflet plugin 655ad75
  • Similar to default behavior of other popular vector map products
  • Can be disabled with modifyDoubleClickZoom: false on initialization of Tangram.leafletLayer
• Data source transform functions will now be invoked for non-tiled and MVT data sources #434
  • Previously, these functions were only applicable to tiled GeoJSON or TopoJSON sources
• Second argument of Scene.load() has been transitioned to a full options object (with backwards compatible support for specifying config_path string as the argument value) d392bb1

Bug Fixes

• On initial map load, do not block map rendering on loading/building of all tiles, e.g. tiles should "pop in" incrementally as they are finished building 92e4455
• Fix bounding boxes for labels with Italic fonts #431

Internal

• Remove use of ES6 features that
  • Are not transpiled efficiently (including for..of loops, generators)
  • Can reduce bundle size by avoiding polyfills (Set, Map)
• Upgrade to TopoJSON 2.x, and use slimmed down fork to only include methods used by Tangram.