import UniformNode from '../core/UniformNode.js';
import { NodeUpdateType } from '../core/constants.js';
import { nodeProxy } from '../tsl/TSLBase.js';
/** @module MatcapUVNode **/
/**
* A special type of uniform node that computes the
* maximum mipmap level for a given texture node.
*
* ```js
* const level = maxMipLevel( textureNode );
* ```
*
* @augments module:UniformNode~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.
*
* @function
* @param {TextureNode} textureNode - The texture node to compute the max mip level for.
* @returns {MaxMipLevelNode}
*/
export const maxMipLevel = /*@__PURE__*/ nodeProxy( MaxMipLevelNode );