Interface StyleImageInterface

Interface for dynamically generated style images. This is a specification for implementers to model: it is not an exported method or class.

Images implementing this interface can be redrawn for every frame. They can be used to animate icons and patterns or make them respond to user input. Style images can implement a StyleImageInterface#render method. The method is called every frame and can be used to update the image.

See

Add an animated icon to the map.

Example

let flashingSquare = {
    width: 64,
    height: 64,
    data: new Uint8Array(64 * 64 * 4),

    onAdd: function(map) {
        this.map = map;
    },

    render: function() {
        // keep repainting while the icon is on the map
        this.map.triggerRepaint();

        // alternate between black and white based on the time
        let value = Math.round(Date.now() / 1000) % 2 === 0  ? 255 : 0;

        // check if image needs to be changed
        if (value !== this.previousValue) {
            this.previousValue = value;

            let bytesPerPixel = 4;
            for (let x = 0; x < this.width; x++) {
                for (let y = 0; y < this.height; y++) {
                    let offset = (y * this.width + x) * bytesPerPixel;
                    this.data[offset + 0] = value;
                    this.data[offset + 1] = value;
                    this.data[offset + 2] = value;
                    this.data[offset + 3] = 255;
                }
            }

            // return true to indicate that the image changed
            return true;
        }
    }
 }

 map.addImage('flashing_square', flashingSquare);
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