@woosh/meep-engine/src/engine/graphics/ecs/mesh-v2/render/adapters/AbstractRenderAdapter.js

Pure JavaScript game engine. Fully featured and production ready.

import {
    array_quick_sort_by_comparator
} from "../../../../../../core/collection/array/array_quick_sort_by_comparator.js";

/**
 *
 * @param {THREE.Object3D|{material?:Material}} a
 * @param {THREE.Object3D|{material?:Material}} b
 * @returns {number}
 */
function compare_by_material(a, b) {

    const a_mat = a.material;
    const b_mat = b.material;

    if (a_mat === b_mat) {
        return 0;
    }

    if (a_mat === undefined) {
        return 1;
    } else if (b_mat === undefined) {
        return -1;
    }

    return a_mat.id - b_mat.id;
}

export class AbstractRenderAdapter {
    constructor() {

        /**
         *
         * @type {number}
         * @protected
         */
        this.__object_count = 0;

        /**
         *
         * @type {THREE.Object3D[]}
         * @protected
         */
        this.__objects = [];
    }

    /**
     * Sorting objects by material will help reduce context switching and number of graphics API calls
     */
    sort_by_material() {
        array_quick_sort_by_comparator(this.__objects, compare_by_material, null, 0, this.__object_count - 1);
    }

    /**
     *
     * @param {THREE.BufferGeometry} geometry
     * @param {THREE.Material} material
     * @param {number} instance_count
     * @returns {number}
     */
    score(geometry, material, instance_count) {
        return 0;
    }

    /**
     * Express intent to draw
     * @param {ShadedGeometry} sg
     * @returns {boolean} true if able to draw immediately, false otherwise
     */
    intend_draw(sg) {
        return true;
    }

    /**
     *
     * @param {ShadedGeometry} sg
     * @returns {void}
     */
    add(sg) {
        throw new Error('Not Implemented');
    }


    /**
     *
     * @param {THREE.WebGLRenderer} renderer
     * @param {CameraView} view
     */
    build_start(renderer, view) {

    }

    build_end() {

    }

    clear() {
        this.__object_count = 0;
    }

    /**
     * Used to perform infrequent housekeeping on the adapter's internal data structures
     * Returns a maintenance sequence
     * @return {Generator}
     */
    * maintain() {
        // override as necessary
    }

    /**
     * @returns {THREE.Object3D[]}
     */
    get objects() {
        return this.__objects;
    }

    /**
     * @returns {number}
     */
    get object_count() {
        return this.__object_count;
    }

    dispose() {

    }
}

/**
 * @readonly
 * @type {boolean}
 */
AbstractRenderAdapter.prototype.isShadedGeometryRenderAdapter = true;