update docs

docs/layers/bitmap-layer.md

@@ -58,7 +58,7 @@ new deck.BitmapLayer({});
 
 ### Data
 
-##### `bitmap` (String|Texture2D|Image|HTMLCanvasElement|HTMLVideoElement)
+##### `image` (String|Texture2D|Image|HTMLCanvasElement|HTMLVideoElement)
 
 - Default `null`.
 

docs/layers/terrain-layer.md

@@ -7,9 +7,9 @@
 
 # TerrainLayer
 
-This TerrainLayer reconstructs mesh surfaces from height map images, e.g. [Mapzen Terrain Tiles](https://github.com/tilezen/joerd/blob/master/docs/formats.md), which encodes elevation into R,G,B values.
+The `TerrainLayer` reconstructs mesh surfaces from height map images, e.g. [Mapzen Terrain Tiles](https://github.com/tilezen/joerd/blob/master/docs/formats.md), which encodes elevation into R,G,B values.
 
-When `terrainImage` is supplied with a templated tile server URL, e.g. URL containing "{x}", it renders terrain tiles globally using the TileLayer and SimpleMeshLayer. Otherwise, supply an absolute URL to `terrainImage` and a `bounds` prop to render a any terrain image (e.g. non-Slippy map tiles) with a SimpleMeshLayer.
+When `elevationData` is supplied with a URL template, i.e. a string containing `'{x}'` and `'{y}'`, it loads terrain tiles on demand using a `TileLayer` and renders a mesh for each tile. If `elevationData` is an absolute URL, a single mesh is used, and the `bounds` prop is required to position it into the world space.
 
 ```js
 import DeckGL from '@deck.gl/react';
@@ -27,8 +27,8 @@ export const App = ({viewport}) => {
       bScaler: 1/256,
       offset: -32768
     },
-    terrainImage: 'https://s3.amazonaws.com/elevation-tiles-prod/terrarium/{z}/{x}/{y}.png',
-    surfaceImage: 'https://wms.chartbundle.com/tms/1.0.0/sec/{z}/{x}/{y}.png?origin=nw'
+    elevationData: 'https://s3.amazonaws.com/elevation-tiles-prod/terrarium/{z}/{x}/{y}.png',
+    texture: 'https://wms.chartbundle.com/tms/1.0.0/sec/{z}/{x}/{y}.png?origin=nw'
   });
   return <DeckGL {...viewport} layers={[layer]} />;
 };
@@ -71,25 +71,21 @@ When in Tiled Mode, inherits from all [TileLayer](/docs/api-reference/tile-layer
 
 ### Data Options
 
-##### `terrainImage` (String)
+##### `elevationData` (String|Array, required)
 
-Image url that encodes height data.
+Image URL that encodes height data.
 
-- Default: `null`
-
-Depending on the `terrainImage` string, this layer renders as a tiled layer composed of a TileLayer of SimpleMeshLayers, or as a single mesh rendered as a SimpleMeshLayer.
-
-* Tiled `terrainImage`: https://s3.amazonaws.com/elevation-tiles-prod/terrarium/{z}/{x}/{y}.png
+- If the value is a valid URL, this layer will render a single mesh.
+- If the value is a string, and contains substrings `{x}` and `{y}`, it is considered a URL template. This layer will render a `TileLayer` of meshes. `{x}` `{y}` and `{z}` will be replaced with a tile's actual index when it is requested.
+- If the value is an array: multiple URL templates. See `TileLayer`'s `data` prop documentation for use cases.
 
-* Non-Tiled `terrainImage`: https://s3.amazonaws.com/elevation-tiles-prod/terrarium/1/1/0.png
 
-##### `surfaceImage` (String|Null, optional)
+##### `texture` (String|Null, optional)
 
-Image url to use as surface texture. Same URL parsing as `terrainImage`.
+Image URL to use as the surface texture. Same schema as `elevationData`.
 
-- Default: `0`
+- Default: `null`
 
-### Mesh Options
 
 ##### `meshMaxError` (Number, optional)
 
@@ -140,25 +136,25 @@ The default value of `elevationDecoder` decodes a grayscale image:
 
 ##### `bounds` (Array, optional)
 
-Bounds of the image to fit x,y coordinates into. In [minX, minY, maxX, maxY] world coordinates. Must be supplied when using as a Non-Tiled terrain, otherwise optional.
+Bounds of the image to fit x,y coordinates into. In `[left, top, right, bottom]` world coordinates. Must be supplied when using non-tiled elevation data.
 
 - Default: `null`
 
-The pixel coordinates start from the top left corner.
+`left`, `bottom`, `right`, `top` refers to the coordinate of the corresponding side of the image.
 
 ##### `workerUrl` (String, optional)
 
-**Advanced** Supply url to local terrain worker bundle. Custom `workerUrl` may be desirable if the application wishes to serve the worker code itself without relying on `unpkg.com`. The worker bundle can be located in `"node_modules/@loaders.gl/terrain/dist/terrain-loader.worker.js"`.
+**Advanced** Supply url to local terrain worker bundle. By default, it points to the latest published `@loaders.gl/terrain` NPM module on [unpkg.com](unpkg.com). Custom `workerUrl` may be desirable if the application wishes to serve the worker code itself without relying on the CDN. The worker bundle can be located locally in `"node_modules/@loaders.gl/terrain/dist/terrain-loader.worker.js"`.
 
-Set `workerUrl` to empty string to disable worker (improves error messages).
+Set `workerUrl` to an empty string to disable worker during debugging (improves error messages).
 
 - Default: `null`
 
 ### Render Options
 
 ##### `color` (Color, optional)
 
-Color to use if `surfaceImage` is unavailable. Equivalent to setting SimpleMeshLayer `getColor` prop to `d => prop.color`.
+Color to use if `texture` is unavailable. Equivalent to setting SimpleMeshLayer's `getColor` prop.
 
 - Default: `[255, 255, 255]`
 
@@ -168,6 +164,16 @@ Forwarded to SimpleMeshLayer `wireframe` prop.
 
 - Default: `false`
 
+
+## Sub Layers
+
+The `TerrainLayer` renders the following sublayers:
+
+* `tiles` - a [TileLayer](/docs/layers/tile-layer.md). Only rendered if `elevationData` is a URL template.
+* `mesh` - a [SimpleMeshLayer](/docs/layers/simple-mesh-layer.md) rendering the terrain mesh.
+
+
+
 # Source
 
 [modules/geo-layers/src/terrain-layer](https://github.com/uber/deck.gl/tree/master/modules/geo-layers/src/terrain-layer)

modules/geo-layers/src/terrain-layer/terrain-layer.js

@@ -143,6 +143,7 @@ export default class TerrainLayer extends CompositeLayer {
   }
 
   renderSubLayers(props) {
+    const SubLayerClass = this.getSubLayerClass('mesh', SimpleMeshLayer);
     const {data, color} = props;
     let mesh = null;
     let texture = null;
@@ -155,7 +156,7 @@ export default class TerrainLayer extends CompositeLayer {
       texture = data.then(result => result && result[1]);
     }
 
-    return new SimpleMeshLayer(props, {
+    return new SubLayerClass(props, {
       data: DUMMY_DATA,
       mesh,
       texture,
@@ -178,7 +179,7 @@ export default class TerrainLayer extends CompositeLayer {
           wireframe,
           color,
           getTileData: this.getTiledTerrainData.bind(this),
-          renderSubLayers: this.renderSubLayers,
+          renderSubLayers: this.renderSubLayers.bind(this),
           updateTriggers: {
             getTileData: {
               elevationData: urlTemplateToUpdateTrigger(elevationData),
@@ -190,7 +191,9 @@ export default class TerrainLayer extends CompositeLayer {
         }
       );
     }
-    return new SimpleMeshLayer(
+
+    const SubLayerClass = this.getSubLayerClass('mesh', SimpleMeshLayer);
+    return new SubLayerClass(
       this.getSubLayerProps({
         id: 'mesh'
       }),