Class ColorMap

Represents a 1D color gradient bounded by a min and max values.

Whenever a color map is associated with a grayscale texture, the color intensity of the texture is used a a parameter to sample the color gradient.

Important: since this color map owns a texture, it is disposable. Don't forget to call dispose() to free texture memory, when you're finished using the colormap.

The mode property describes how the intensity of the pixel is interpreted:

Elevation simply takes the intensity value of the pixel, Slope gets the slope of the pixel (assuming it is an elevation texture), and Aspect gets the aspect (orientation from the north) of the pixel (assuming it is an elevation texture).

The min and max properties describe how the colormap is applied relative to the intensity of the sampled pixel.

Pixel intensities outside of those bounds will take the color of the bound that is the closest (i.e if the intensity is greater than max, the color will be the rightmost color of the color ramp).

The colors property takes an array of colors. To create this array, you can use libraries such as colormap or chroma-js to generate the color ramp.

To obtain a "discrete" color map, you should use a small number of colors in the ramp. Conversely, to obtain a "linear", continuous color map, you should use a high number of colors, typically 256 values.

Example

// Create a color map for elevations between 0 and 2500 meters.
const colors = makeColorRamp(); // Use whatever library to generate the ramp.
const colorMap = new ColorMap({ colors, min: 0, max: 2500, mode: ColorMapMode.Elevation });

const texture = colorMap.getTexture();

// Disable the color map.
colorMap.active = false;

// When finished with this color map, dispose it.
colorMap.dispose();

Hierarchy

EventDispatcher<ColorMapEvents>
- ColorMap

Index

Constructors

constructor

new ColorMap(
    options: {
        colors: Color[];
        max: number;
        min: number;
        mode?: ColorMapMode;
        opacities?: number[];
    },
): ColorMap
Creates an instance of ColorMap.
Parameters
- options: {
      colors: Color[];
      max: number;
      min: number;
      mode?: ColorMapMode;
      opacities?: number[];
  }
  The constructor options.
  - colors: Color[]
    The colors of this color map.
  - max: number
    The upper bound of the color map range.
  - min: number
    The lower bound of the color map range.
  - Optionalmode?: ColorMapMode
    The mode of the color map
  - Optionalopacities?: number[]
    The opacity values of the color map. If defined, must have the same number of values as the colors array.
Returns ColorMap
Overrides EventDispatcher<ColorMapEvents>.constructor
- Defined in core/ColorMap.ts:81

Accessors

active

get active(): boolean
Enables or disables the color map.

Returns boolean
- Defined in core/ColorMap.ts:152
set active(v: boolean): void
Parameters
- v: boolean
Returns void
- Defined in core/ColorMap.ts:156

colors

get colors(): Color[]
Gets or sets the colors of the color map.

Note: if there is already an array defined in the opacity property, and this array does not have the same length as the new color array, then it will be removed.

Returns Color[]
- Defined in core/ColorMap.ts:197
set colors(v: Color[]): void
Parameters
- v: Color[]
Returns void
- Defined in core/ColorMap.ts:201

max

get max(): number
Gets or sets the upper bound of the color map range.

Returns number
- Defined in core/ColorMap.ts:180
set max(v: number): void
Parameters
- v: number
Returns void
- Defined in core/ColorMap.ts:184

min

get min(): number
Gets or sets the lower bound of the color map range.

Returns number
- Defined in core/ColorMap.ts:166
set min(v: number): void
Parameters
- v: number
Returns void
- Defined in core/ColorMap.ts:170

mode

get mode(): ColorMapMode

Gets or sets the color map mode.

Returns ColorMapMode

Example

// Start with an elevation gradient, ranging from 100 to 1500 meters.
const colorMap = new ColorMap({ colors, min: 100, max: 1500, mode: ColorMapMode.Elevation });

// Change mode to slope, and set min and max to 0-90 degrees.
colorMap.mode = ColorMapMode.Slope;
colorMap.min = 0;
colorMap.max = 90;

set mode(v: ColorMapMode): void
Parameters
- v: ColorMapMode
Returns void
- Defined in core/ColorMap.ts:138

opacity

get opacity(): number[] | null
Gets or sets the opacity values of the color map.

Note: if the provided array does not have the same length as the colors array, an exception is raised.

Returns number[] | null
Default Value
```
null
```
- Defined in core/ColorMap.ts:221
set opacity(v: number[] | null): void
Parameters
- v: number[] | null
Returns void
- Defined in core/ColorMap.ts:225

Methods

clone

clone(): ColorMap
Clones this colormap.

Returns ColorMap
- Defined in core/ColorMap.ts:297

dispose

dispose(): void
Disposes the texture owned by this color map.

Returns void
- Defined in core/ColorMap.ts:310

getTexture

getTexture(): DataTexture
Returns a 1D texture containing the colors of this color map.

Returns DataTexture
The resulting texture.
- Defined in core/ColorMap.ts:275

sample

sample(value: number): Color
Samples the colormap for the given value.
Parameters
- value: number
  The value to sample.
Returns Color
The color at the specified value.
- Defined in core/ColorMap.ts:241

sampleOpacity

sampleOpacity(value: number): number
Samples the transparency for the given value.
Parameters
- value: number
  The value to sample.
Returns number
The color at the specified value.
- Defined in core/ColorMap.ts:256

Class ColorMap

Example

Hierarchy

Index

Constructors

Accessors

Methods

Constructors

constructor

Parameters

colors: Color[]

max: number

min: number

Optionalmode?: ColorMapMode

Optionalopacities?: number[]

Returns ColorMap

Accessors

active

Returns boolean

Parameters

Returns void

colors

Returns Color[]

Parameters

Returns void

max

Returns number

Parameters

Returns void

min

Returns number

Parameters

Returns void

mode

Returns ColorMapMode

Example

Parameters

Returns void

opacity

Returns number[] | null

Default Value

Parameters

Returns void

Methods

clone

Returns ColorMap

dispose

Returns void

getTexture

Returns DataTexture

sample

Parameters

Returns Color

sampleOpacity

Parameters

Returns number

Settings

On This Page

`Optional`mode?: ColorMapMode

`Optional`opacities?: number[]