Global

Methods

addStyle(name, fn, optionsopt) → {void}

Add a new style or update an existing one Supports two types of styles:

  • Type 1 (Direct RGBA): Function returns [r, g, b, a] directly
  • Type 2 (Gradient): Function returns [scalar, 0, 0, alpha] with colors/stops/domain in options
Parameters:
Name Type Attributes Default Description
name string

Unique style name
fn function

GPU.js kernel function that processes band data
options Object <optional>
 {}

Configuration for gradient-based styles (Type 2)

Properties
Name Type Attributes Description
colors Array.<string> <optional>

Array of hex color strings for gradient
stops Array.<number> <optional>

Array of stop values corresponding to colors
domain Array.<number> <optional>

Optional scalar domain [min, max] for LUT mapping
Source:
Returns:
Type
void
Example
// Type 1: Direct RGBA
multiband.addStyle('True Color', function(data) {
  const r = data[3][this.thread.y][this.thread.x] * 0.00003051757;
  const g = data[2][this.thread.y][this.thread.x] * 0.00003051757;
  const b = data[1][this.thread.y][this.thread.x] * 0.00003051757;
  return [r, g, b, 0.8];
});

// Type 2: Gradient
multiband.addStyle('NDVI', function(data) {
  const b4 = data[3][this.thread.y][this.thread.x];
  const b8 = data[7][this.thread.y][this.thread.x];
  const ndvi = (b8 - b4) / (b8 + b4);
  return [ndvi, 0, 0, 0.8];
}, {
  colors: ['#a50026', '#d73027', '#006837'],
  stops: [-0.2, 0.0, 0.8],
  domain: [-1.0, 1.0]
});

destroyLumaTextureRef(tileDataResult) → {void}

Destroy luma texture reference from tile data result

Parameters:
Name Type Description
tileDataResult Object

Tile data with _lumaTexture property
Source:
Returns:
Type
void

(async) geoKeysParser(geoKeys) → {Promise.<Object>|string|Object|string}

Parse GeoTIFF projection keys and transform to proj4 definition Extracts EPSG code from geoKeys and returns proj4-compatible CRS definition

Parameters:
Name Type Description
geoKeys Object

GeoTIFF geokeys object
Source:
Throws:

If geoKeys is invalid or no projection code found

Type
Error
Returns:

  • Promise resolving to CRS definition object

    Type
    Promise.<Object>

  • return.def - proj4 definition string (e.g., 'EPSG:4326')

    Type
    string

  • return.parsed - Parsed proj4 CRS object

    Type
    Object

  • return.coordinatesUnits - Units of the coordinate system

    Type
    string

getActiveStyle() → {string}

Get the name of the currently active style

Source:
Returns:

Active style name

Type
string

getPixelValues(lngLat, target, layerIdopt) → {Object|null}

Sample pixel values from loaded tiles at clicked lngLat position Evaluates the active style at the sampled pixel location

Parameters:
Name Type Attributes Default Description
lngLat Array.<number> | Object

Click position as [lng, lat] or {lng, lat}
target Object

deck.gl instance or map-like object exposing __deck
layerId string <optional>
 'cog-layer'

COGLayer id to sample from
Properties:
Name Type Description
latlng Object

Clicked position {lat, lng}
selectedstyle string

Active style name
value *

Style function output at sampled pixel (Type 1: RGBA array, Type 2: scalar)
bands Array.<number>

Raw band values at sampled pixel
Source:
Returns:

Sampled pixel data or null if sampling fails

Type
Object | null

getStyles() → {Array.<string>}

Get an array of all available style names Results are cached and only recomputed when styles are added/removed

Source:
Returns:

Array of style names

Type
Array.<string>

(async) getTileData(image, optionsopt) → {Promise.<Object>}

Fetch and process tile data from a GeoTIFF for GPU rendering Converts raster data to band-major Float32Array format suitable for GPU.js

Parameters:
Name Type Attributes Default Description
image Object

GeoTIFF image object with fetchTile method
options Object <optional>
 {}

Fetch options

Properties
Name Type Attributes Description
x number

Tile X coordinate
y number

Tile Y coordinate
signal AbortSignal <optional>

Abort signal for fetch cancellation
device Object

WebGL device/context
Properties:
Name Type Description
data Float32Array

Band-major float32 raster data
width number

Tile width in pixels
height number

Tile height in pixels
bandCount number

Number of bands
device Object

WebGL device
Source:
Throws:

If raster array is missing from fetched tile

Type
Error
Returns:

Promise resolving to tile data

Type
Promise.<Object>

releaseBlitResources(gl) → {void}

Release all cached blit resources for a WebGL context Deletes framebuffers, VAOs, programs, and LUT textures

Parameters:
Name Type Description
gl WebGL2RenderingContext

WebGL context
Source:
Returns:
Type
void

removeStyle(name) → {void}

Remove a style from the collection The default style "Band 1 - grayscale" cannot be removed

Parameters:
Name Type Description
name string

Style name to remove
Source:
Returns:
Type
void

renderTile(tileDataResult, multibandInstance) → {Array.<Object>}

Render a tile using the active style from the multiband instance Applies GPU-accelerated style kernel to raster data and returns RasterModule array

For Type 1 styles: Applies kernel directly to produce RGBA output For Type 2 styles: Applies kernel to produce scalar values, then maps through color LUT via GPU shader

Parameters:
Name Type Description
tileDataResult Object

The tile data with texture information

Properties
Name Type Description
data Float32Array

Band-major float32 raster data
width number

Tile width in pixels
height number

Tile height in pixels
bandCount number

Number of bands
device Object

WebGL device
multibandInstance Object

The multiband instance with GPU and style management
Source:
Throws:

If no active style or kernel is available

Type
Error
Returns:

Array of RasterModule objects backed by luma textures

Type
Array.<Object>

setActiveStyle(name, targetopt, layerIdopt) → {void}

Set the active rendering style and optionally refresh tiles If the style is not found, defaults to "Band 1 - grayscale"

Parameters:
Name Type Attributes Default Description
name string

Style name to activate
target Object <optional>

deck.gl instance or map-like object exposing __deck; if provided, tiles are refreshed immediately
layerId string <optional>
 'cog-layer'

COGLayer id used when refreshing tiles
Source:
Returns:
Type
void