InfiniteWorkerExternalGeometry.ts

import {
    BufferGeometry
} from 'three';
import {
    WorkerTaskCommandResponse,
    WorkerMessage,
    WorkerTaskWorker,
    comRouting
} from 'wtd-core';
import {
    MeshPayload
} from 'wtd-three-ext';

class InfiniteWorkerExternalGeometry implements WorkerTaskWorker {

    private bufferGeometry?: BufferGeometry = undefined;

    init(message: WorkerMessage) {
        const wm = WorkerMessage.unpack(message, false);
        if (wm.payloads.length > 0) {
            this.bufferGeometry = (wm.payloads[0] as MeshPayload).message.bufferGeometry as BufferGeometry;
        }

        const initComplete = WorkerMessage.createFromExisting(message, {
            overrideCmd: WorkerTaskCommandResponse.INIT_COMPLETE
        });
        self.postMessage(initComplete);
    }

    execute(message: WorkerMessage) {
        if (!this.bufferGeometry) {
            self.postMessage(new Error('No initial payload available'));
        } else {
            // clone before re-using as othewise transferables can not be obtained
            const geometry = this.bufferGeometry.clone();

            geometry.name = 'tmProto' + message.uuid;

            const vertexArray = geometry.getAttribute('position').array;
            for (let i = 0; i < vertexArray.length; i++) {
                vertexArray[i] = vertexArray[i] + 10 * (Math.random() - 0.5);
            }

            const meshPayload = new MeshPayload();
            meshPayload.setBufferGeometry(geometry, 2);

            const randArray = new Uint8Array(3);
            self.crypto.getRandomValues(randArray);
            meshPayload.message.params = {
                color: {
                    r: randArray[0] / 255,
                    g: randArray[1] / 255,
                    b: randArray[2] / 255
                }
            };

            const execComplete = WorkerMessage.createFromExisting(message, {
                overrideCmd: WorkerTaskCommandResponse.EXECUTE_COMPLETE
            });
            execComplete.addPayload(meshPayload);

            const transferables = WorkerMessage.pack(execComplete.payloads, false);
            self.postMessage(execComplete, transferables);
        }
    }
}

const worker = new InfiniteWorkerExternalGeometry();
self.onmessage = message => comRouting(worker, message);