@openhps/core/dist/esm/three/nodes/utils/MaxMipLevelNode.js

Open Hybrid Positioning System - Core component

import UniformNode from '../core/UniformNode.js';
import { NodeUpdateType } from '../core/constants.js';
import { nodeProxy } from '../tsl/TSLBase.js';

/**
 * A special type of uniform node that computes the
 * maximum mipmap level for a given texture node.
 *
 * ```js
 * const level = maxMipLevel( textureNode );
 * ```
 *
 * @augments UniformNode
 */
class MaxMipLevelNode extends UniformNode {
  static get type() {
    return 'MaxMipLevelNode';
  }

  /**
   * Constructs a new max mip level node.
   *
   * @param {TextureNode} textureNode - The texture node to compute the max mip level for.
   */
  constructor(textureNode) {
    super(0);

    /**
     * The texture node to compute the max mip level for.
     *
     * @private
     * @type {TextureNode}
     */
    this._textureNode = textureNode;

    /**
     * The `updateType` is set to `NodeUpdateType.FRAME` since the node updates
     * the texture once per frame in its {@link MaxMipLevelNode#update} method.
     *
     * @type {string}
     * @default 'frame'
     */
    this.updateType = NodeUpdateType.FRAME;
  }

  /**
   * The texture node to compute the max mip level for.
   *
   * @readonly
   * @type {TextureNode}
   */
  get textureNode() {
    return this._textureNode;
  }

  /**
   * The texture.
   *
   * @readonly
   * @type {Texture}
   */
  get texture() {
    return this._textureNode.value;
  }
  update() {
    const texture = this.texture;
    const images = texture.images;
    const image = images && images.length > 0 ? images[0] && images[0].image || images[0] : texture.image;
    if (image && image.width !== undefined) {
      const {
        width,
        height
      } = image;
      this.value = Math.log2(Math.max(width, height));
    }
  }
}
export default MaxMipLevelNode;

/**
 * TSL function for creating a max mip level node.
 *
 * @tsl
 * @function
 * @param {TextureNode} textureNode - The texture node to compute the max mip level for.
 * @returns {MaxMipLevelNode}
 */
export const maxMipLevel = /*@__PURE__*/nodeProxy(MaxMipLevelNode).setParameterLength(1);