three.js/src/core/DynamicBufferAttribute.js

import { _Math } from '../math/Math.js';

/**
 * @author raub / https://github.com/raub
 */


function DynamicBufferAttribute( gl, buffer, type, itemSize, count ) {

	this.sizes = [
		[gl.FLOAT, 4],
		[gl.UNSIGNED_SHORT, 2],
		[gl.SHORT, 2],
		[gl.UNSIGNED_INT, 4],
		[gl.INT, 4],
		[gl.BYTE, 1],
		[gl.UNSIGNED_BYTE, 1],
	].reduce(function (accum, current) {
		accum[current[0]] = current[1];
		return accum;
	}, {});

	if ( ! this.sizes[type] ) {
		throw new TypeError( 'THREE.DynamicBufferAttribute: unsupported GL data type.' );
	}

	this.uuid = _Math.generateUUID();

	this.buffer = buffer;
	this.type = type;
	this.itemSize = itemSize;
	this.elementSize = this.sizes[type];
	this.count = count;

	this.version = 0;

}

Object.defineProperty( DynamicBufferAttribute.prototype, 'needsUpdate', {

	set: function ( value ) {

		if ( value === true ) this.version ++;

	}

} );

Object.assign( DynamicBufferAttribute.prototype, {

	isDynamicBufferAttribute: true,

	setBuffer: function ( buffer ) {

		this.buffer = buffer;

		return this;

	},

	setType: function ( type ) {

		if ( ! sizes[type] ) {
			throw new TypeError( 'THREE.DynamicBufferAttribute: unsupported GL data type.' );
		}

		this.type = type;
		this.elementSize = this.sizes[type];

		return this;

	},

	setItemSize: function ( itemSize ) {

		this.itemSize = itemSize;

		return this;

	},

	setCount: function ( count ) {

		this.count = count;

		return this;

	},

} );


export { DynamicBufferAttribute };