v0.13.2

Bug Fixes

• Add null checks on camera and view to prevent exceptions during initialization in some cases.
• Restore application of color and filter shader blocks to standalone text styles (as expected, these blocks are still not applied to text attached to a points style).
• Fix array iteration when applying globals, prevents worker data clone exceptions when Tangram is used alongside another library that modifies the underlying array prototype (such as Ember).

Internal

• Only mark scene as animating when animated styles are currently in view; improves idle performance for scenes with animated styles only used at some zooms or areas.

v0.13.1

Mostly internal refactoring to provide more flexibility and better performance on platforms such as iOS Mobile Safari that are sensitive to main thread/UI locking.

Bug Fixes

• Fix a few cases where labels would render incorrectly due to improper placement in the Canvas text atlas.
• Skip boundary labels if neither a left nor a right value was found. Fixes issue where some tiles wouldn't render; collision detection would never resolve for a given style/tile combination consisting of only empty boundary labels.

Internal

• Use 512px tiles for non-tiled data sources, for better label placement (fewer tile boundaries).
• Refactor Canvas text atlas creation for labels, to allow a single tile to place labels across multiple textures, with a maximum texture size per atlas of 2048x2048 pixels; the max texture size was chosen as a balance between minimizing the number of textures created, and the time needed to instantiate a GL texture from a Canvas element, which can cause a significant main thread lock on some platforms.
• Add "background task" model, to allow some long-running processes on the main thread (such as Canvas text label rendering) to be time-sliced across multiple animation frames; this ameliorates thread and UI locking when these processes take several frames (e.g. hundreds of milliseconds or more) to complete. Background tasks can be paused when individual tasks (or all tasks collectively) surpass a certain time threshold per frame, or when the user is interacting with the map.
• A given rendering style can now have multiple mesh "variants", which can vary by rendering state such as uniform values; this is used to vary the label atlas texture sampler when a given tile/style combination has more than one label texture.
• Remove optional stringification of worker message payloads, due to inconclusive benefit on current browser generations.
• Upgrade browserify.

v0.13.0

New Functionality

• Support for 512px sized tiles #548
  • While web map tiles are traditionally displayed at a size of 256px (logical pixels) each, some tile services now provide tiles with a larger intended display size, such as 512px. This reduces the total number of tiles that need to be requested for any given view (since each tile covers more screen area).
  • A tile size of 512px will fetch tiles that are one zoom level lower than the current view zoom. For example, if the view is at z16, then the corresponding z15 tile coordinates for that area will be fetched, and each will cover the 512x512 area traditionally occupied by four separate 256x256 tiles. This scheme ensures that, regardless of the display tile size being used, any given web map tile XYZ coordinate will correspond to the same geographical extent.
  • Tangram data sources can enable larger tile sizes with the tile_size parameter, e.g.

  sources:
     mapzen:
        type: ...
        url: ...
        tile_size: 512
  

  • tile_size must be a power of 2 greater than or equal to 256 (and should not include any units such as px suffix)
• Ability to query features from tile data #566
  • A new Scene.queryFeatures() method allows for directly querying tile data, with options to filter by feature properties and scene visibility, and group results by parameters or specify criteria for uniqueness. Matching features are returned with their properties, and optionally with their geometry when requested.
  • Tiles that intersect the current viewport are queried. Therefore the results will include the visible area, but may include nearby features as well.
  • Query results are returned as a promise that resolves with an array of matching features.
  • An optional filter object can be provided, using the same syntax used for selecting features for styling in layers. If no filter is provided, all features will be returned (subject to other parameters defined below).
  • Example: scene.queryFeatures({ filter: { $layer: 'pois', kind: 'restaurant' } }) will return all restaurants in the pois layer.
  • See #566 for further details on filter, visible, group_by, unique, and geometry options.
  • This functionality is separate from the existing Scene.getFeatureAt() method, which returns a single feature at a given pixel location.
• Optional pixel radius parameter for the Scene.getFeatureAt() method #571
  • Previously, Scene.getFeatureAt() only returned a feature that was present at the exact pixel location provided. There are cases where a larger radius is useful, such as mobile devices where input is not as precise, or features rendered with thin lines that may be difficult to select.
  • The following methods can now specify radius:
    • Direct scene interface:
      • scene.getFeatureAt(pixel, { radius })
    • Leaflet layer interface for setting selection handlers:
      • layer.setSelectionEvents (events, { radius })
    • Leaflet layer instantiation:

      layer = Tangram.leafletLayer({
         scene: 'path/to/scene.yaml',
         events: {
            click: clickHandler,
         },
         selectionRadius: 10
      };
      

  • radius or selectionRadius is an optional value in pixels (the default matches existing behavior, where radius is zero). When using a radius, the feature closest to the center point will be returned. As with existing feature selection, only features marked as interactive: true will register.
  • This feature also provides parity with Tangram ES.
• Optional background color parameter for screenshots #570
  • Adds an optional background color that will be blended with any translucent pixels in the scene when capturing a screenshot. In normal browser presentation, these pixels are blended with whatever HTML content is behind them. With this optional parameter, users have more control to achieve similar results when capturing a screenshot.
  • The default background color value is white, as this is most likely to match default browser display (white Canvas background). Background can be set to any other color value accepted by Tangram (e.g. red, [0.5, 0.5, 0]), including transparent, which would preserve a transparent background from Tangram.
  • Example of capturing screenshot and opening in window:
    • scene.screenshot({ background: 'transparent' }).then(s => window.open(s.url))
• Curved labels for Arabic #564
  • Thanks to additional work by @mapmeld, curved labels now also support Arabic text. Tangram JS now supports curved labels for all text except for: bidirectional text (mixed explicit LTR and RTL characters -- neutral characters like punctuation or numbers are OK), and Mongolian script (these will still render, just as straight line labels).
• File type option for loading zip files from local blob #572
  • Previously, the scene URL had to end in '.zip' when loading zipped scene files. To support cases where zipped files may be loaded locally, such as from a blob URL (see #565), a new file type option is provided.
  • file_type when using Scene.load():
    • scene.load(zip_blob_url, { file_type: 'zip' });
  • sceneFileType when using Tangram.leafletLayer:

    layer = Tangram.leafletLayer({
       scene: zip_blob_url,
       sceneFileType: 'zip',
       ...
    });
    

Bug Fixes

• Fix override of array values (such as for zoom-based stops) when using default draw parameters for a style #568
• Handle over-zooming of raster tiles when wrapping around dateline f36098d
• Exclude any non-texture-specific props when comparing texture definitions (fixes reference count / flicker bug with over-zoomed raster tiles) 70a7bd7
• Don't count over-zoomed tiles against max proxy depth b9afe9d
• Shallow copy when loading a scene directly from a JS object, to allow a single scene config object to be loaded multiple times (may need to address modification of nested properties in the future) c0442b9
• Copy colors to avoid modifying the underlying object (fixes a case where a global color value used for multiple substitutions was being converted to a 4-element RGBA array, while some substitutions still expected the original 3-element RGB value) 1ef7a8c
• Don't use scene clear color for selection buffer (could manifest as incorrect feature selection results, though this has not been observed) 68d4832

Internal

• scene.config_path is renamed to the more intuitive scene.base_path. The existing scene.config_path accessor will be maintained for now, but eventually deprecated.
• Options to scene.load() should be passed as an object, e.g.:
  • scene.load(scene_url, { base_path: 'https://site.com/scene/resources/' });
  • The previous public documented API only had a single second argument, which was used for base path -- this is still backwards compatible but should be discouraged. Documentation will be updated.
• Simplification and caching of some RTL text handling.

v0.12.5

Improvements

• Support curved labels in several additional languages #555
  • Adds curved label support for Burmese, Bengali, Devanagari, Khmer, Gujarati, Gurmukhi, Kannada, Lao, Malayalam, Oriya, Sinhala, Tamil, Thai, Tai Tham, Telugu, and Tibetan
  • Use grapheme clusters (instead of characters) to find appropriate visual breakpoints
  • Thanks to @mapmeld for the contribution and language expertise!
• Allow introspection flag to be passed as an option to Tangram.leafletLayer a347632
  • e.g. Tangram.leafletLayer({ scene: 'scene.yaml', introspection: true }) will load the scene with introspection enabled, making a call to scene.setIntrospection(true) unnecessary

Bug Fixes

• Fix bug where a style's default draw parameters could not be overridden a8011a1
• Fix additional right-to-left text issues (mis-classification of neutral characters as RTL)
• Fix incorrect colors in screenshots capture in Firefox #551
• Avoid the need for a custom UglifyJS plugin when bundling Tangram with Webpack
  #559 f9e4cef
• Suppress source map URL from minified build (prevent console warnings when source map not found)

Internal

• Don't request tiles for a data source if no top-level layers are enabled for it (saves networks requests) #560
• Cache text segmentation for improved label performance

v0.12.4

Bug Fixes

• Fix right-to-left text handling of neutral characters (e.g. punctuation) in multi-line (text wrapping) labels, and additional case for curved labels #541
• Fix missing spaces in curved labels with text wrapping enabled
  • N.B.: curved labels currently do not support text wrapping; however, enabling the text_wrap parameter should not interfere with rendering of curved labels (this fixes a bug where the spaces in these labels were disappearing)

Functionality Changes

• Apply scene normalization, such as expanding paths relative to the scene's base URL, when the scene config is updated at run-time with scene.updateConfig()

Internal

• Minor optimizations

v0.12.3

Bug Fixes

• Feature selection: only reset appropriate sources on partial rebuild
  • Fixes issue where scene.setDataSource() would clear selection for all data sources, incorrectly removing some feature interactivity #552
• Encapsulate point shader code to prevent namespace collisions with user-defined shader blocks f41813a

Internal

• Optimize GL VBO build process by dynamically compiling JS-to-typed-array function per unique vertex layout
• Improve error/log info for style compilation errors

v0.12.2

Bug Fixes

• Fix inconsistent offset direction for non-boundary labels #542 #545
• Fix inaccurate centroid calculation on small polygons #550
• Fix handling of neutral characters (e.g. punctuation, etc.) in RTL-text curved labels #541 #543
  • N.B.: work on-going to fix similar issue w/multi-line labels
• Fix loading of raster tiles on Edge/IE #538

Functionality Changes

• Consistent label direction for near-vertical lines #517 #532
• Do not apply shader blocks on points-based styles to attached text labels #549
  • Note: this provides compatibility with Tangram ES behavior; this change may affect the appearance of text in existing styles, however, this specific style combination is rare and text will continue to display.
• Add debug option to collect per-layer stats #544
• Allow Tangram debug settings to be passed in when creating Leaflet layer d911d42
  • e.g. layer = Tangram.leafletLayer({ scene: path/to/scene.yaml, debug: { layer_stats: true } });

v0.12.1

New Features

• WebGL context options can now be passed when creating the Tangram Leaflet layer #526
  • For advanced use cases where the user may want to override Tangram's WebGL defaults, or directly access the Tangram Canvas. Example:

    layer = Tangram.leafletLayer({
      scene: ...,
      webGLContextOptions: { // explicitly add/override WebGL context options
        preserveDrawingBuffer: true,
        antialias: false
      }
    });
  

Bug Fixes

• Fix handling of Leaflet minZoom and noWrap options #529

Internal

• Prune layer and text caches to improve memory usage.
• Parse sublayers progressively (as the parent layer first matches a feature) to improve startup / tile build time.
• Improve memory usage for textures by not keeping reference to source data.
• Small improvements to text calculation by skipping unnecessary Canvas measureText() calls.
• Adjust build process for source maps, so live-reload source map doesn't conflict with official build.

v0.12.0

Enhancements & Syntax Changes

• Library can be bundled as a JavaScript UMD module #488 #252
  • Constraints that prevented the Tangram library from being bundleable using popular JS bundling tools such as browserify, webpack, or vanilla file concatenation have been removed. You can now require() or import Tangram. This also removes the requirement to serve the Tangram library under a specific filename.
• Curved labels #484
  • Labels placed along lines will now fit to curves where possible. Placement heuristics have also been overhauled, leading to more label placements (both straight and curved) that better fit the underlying line segment.
    
• Explicit left and right-side line labels #516
  • The text_source parameter has been expanded to optionally accept a mapping with separate left and right values. Each of these values is evaluated as a single text_source value is (as a string, array, or JS function). Example:

  draw:
    text:
      ...
      text_source:
        left: 'name:left'    # feature property name for left-side labels
        right: 'name:right'  # feature property name for right-side labels
  

  • Separate left and right-side labels are then placed along the line, with each label automatically offset by the height of the text. An additional offset can be optionally applied, with the Y value pushing each label in an opposite direction, away from the line.
  • This syntax is useful for dual-sided administrative boundary labels in a single feature, such as those provided by Mapzen's vector tile service:
    
• Point outlines #472 #508
  • Styling parameters have been added to allow for outlines drawn on points-based styles. A new outline block can be provided within the draw block, with color and width parameters (similar to outlines on the lines style).
  • For example, to draw a 10px red dot, with a 2px white border:

  draw:
    points:
      color: red
      size: 10px
      outline:
        color: white
        width: 2px
  

  • Both the width and color parameters in the outline block can also be JS functions, for example to set outline width by building height: width: function() { return feature.height/50; }
  • Point outlines are ignored if a points-based style has a texture/sprite set.
  • Example of points representing buildings, dynamically sized with JS function based on building height:
    
• Style definitions can specify default draw parameters #504 #489
  • Enables a rendering style to include defaults for draw parameters. Any parameters specified in a optional draw block under the style's definition (within styles) will be automatically copied whenever that style is drawn (using a layer draw block under layers).
  • These defaults can be overridden or supplemented as usual by draw blocks within layers.
  • An example, setting a default size for an icons style:

  styles:
    # setting up style with default draw size
    icons:
      base: points
      texture: icons
      draw:
        size: 16px # default size
  
  layers:
    ...
    draw:
      # drawing style with default size, plus setting sprite
      icons:
        sprite: coffee
  

• Data sources can specify optional subdomain list #445 #525
  • New {s} and url_subdomains parameters can be used together to distribute tile requests across multiple subdomains:

  sources:
    source-name:
      type: MVT
      url: https://{s}.some-tile-server.com/{z}/{y}/{x}.mvt
      url_subdomains: [a, b, c]
  

  • This example would cause the following hosts to be used for tile requests:
    • https://a.some-tile-server.com/{z}/{y}/{x}.mvt
    • https://b.some-tile-server.com/{z}/{y}/{x}.mvt
    • https://c.some-tile-server.com/{z}/{y}/{x}.mvt
• Layer-level visible parameter changed to enabled #523 tangrams/tangram-docs#198
  • This parameter has been renamed to enabled to prevent confusion with the separate draw group-level visible property, which continues to exist as-is. These two parameters appear close to one another within the layers hierarchy and were often mixed up.
  • Backwards compatibility is provided for the previous visible property name: if the enabled parameter is undefined for a given layer, any value for visible will be used instead. However, layer-level visible will be deprecated in a future release.
  • Tangram JS's treatment of the layer enabled (nee visible) parameter is also updated to match that of Tangram ES: once set by a layer, the parameter cannot be overridden by any descendant layers. This is useful for culling large portions of the layer tree, e.g. for layer-toggle controls and/or overlays. The draw group-level visible property continues to provide more fine-grained control with inheritance, where needed.
• Warn when a data source specifies parameter names in url_params that already exist in the url query string #515
• Improve rendering of shader-drawn points (e.g. those not using a texture/sprite)
  • Antialiased shader
  • Don't snap to the pixel grid #481

Bug Fixes

• Features without an order parameter will not be drawn (unless the blend mode is set to overlay). A warning will be logged #503
  • This is to provide consistent rendering behavior and to bring Tangram JS into parity with Tangram ES; some small style adjustments may be needed.
• Lookup global property names recursively, so globals can reference other globals fe6ff61
• Point widths have been fixed on high pixel density displays #492
• Fix miter limit fallback to bevel join 5addb37
• Handle GeoJSON features with a null geometry field in non-tiled data sources (includes upgrading geojson-vt).
• Convert null draw groups into empty objects so they don't overwrite those higher in the layer tree during merging.
• Handle race conditions where tiles are canceled mid-build.
• Warn on initial null values for uniforms in a style definition, and skip shader injection.

Deprecated

• The scene.reload() API has been removed; it is synonymous with scene.load() #451
• The scene.rebuildGeometry() API has been removed; it is synonymous with scene.rebuild() #511

v0.11.8

Bug Fixes

• Add null check to prevent errors when requesting feature selection before the scene is initialized