loaders/OverlayLoader.js

/**
* Used for Map tiles
* @class ObjectDefinition
* @category Definitions
* @hideconstructor
*/
export class OverlayDefinition {
    /** 
    * The ID of this Overlay
    * @type {number} 
    */
    id;    

    /** 
    * RGB Colour
    * @type {number} 
    */
    color = 0;  

    /** 
    * Overlay texture
    * @type {number} 
    */
    texture = -1;    

    /** 
    * Hide UnderlayDefinition
    * @type {boolean} 
    */
    hideUnderlay = true;    

    /** 
    * RGB Colour
    * @type {number} 
    */
    secondaryColor = -1;
}

export default class OverlayLoader {

    load(bytes, id) {
        let def = new OverlayDefinition();
        def.id = id;
        let dataview = new DataView(bytes.buffer);
        do {
            var opcode = dataview.readUint8();
            this.handleOpcode(def, opcode, dataview);
        } while (opcode != 0);

        return def;
    }

    handleOpcode(def, opcode, dataview) {
        if (opcode == 0) {
            return;
        }

        if (opcode == 1) {
            def.color = dataview.readInt24();
        }
        else if (opcode == 2) {
            def.texture = dataview.readUint8();
        }
        else if (opcode == 5) {
            def.hideUnderlay = false;
        }
        else if (opcode == 7) {
            def.secondaryColor = dataview.readInt24();
        }
    }
}