Cesium-Prequel/Source/ThirdParty/GltfPipeline/getComponentReader.js

import ComponentDatatype from '../../Core/ComponentDatatype.js'

    /**
     * Returns a function to read and convert data from a DataView into an array.
     *
     * @param {Number} componentType Type to convert the data to.
     * @returns {ComponentReader} Function that reads and converts data.
     *
     * @private
     */
    function getComponentReader(componentType) {
        switch (componentType) {
            case ComponentDatatype.BYTE:
                return function (dataView, byteOffset, numberOfComponents, componentTypeByteLength, result) {
                    for (var i = 0; i < numberOfComponents; ++i) {
                        result[i] = dataView.getInt8(byteOffset + i * componentTypeByteLength);
                    }
                };
            case ComponentDatatype.UNSIGNED_BYTE:
                return function (dataView, byteOffset, numberOfComponents, componentTypeByteLength, result) {
                    for (var i = 0; i < numberOfComponents; ++i) {
                        result[i] = dataView.getUint8(byteOffset + i * componentTypeByteLength);
                    }
                };
            case ComponentDatatype.SHORT:
                return function (dataView, byteOffset, numberOfComponents, componentTypeByteLength, result) {
                    for (var i = 0; i < numberOfComponents; ++i) {
                        result[i] = dataView.getInt16(byteOffset + i * componentTypeByteLength, true);
                    }
                };
            case ComponentDatatype.UNSIGNED_SHORT:
                return function (dataView, byteOffset, numberOfComponents, componentTypeByteLength, result) {
                    for (var i = 0; i < numberOfComponents; ++i) {
                        result[i] = dataView.getUint16(byteOffset + i * componentTypeByteLength, true);
                    }
                };
            case ComponentDatatype.INT:
                return function (dataView, byteOffset, numberOfComponents, componentTypeByteLength, result) {
                    for (var i = 0; i < numberOfComponents; ++i) {
                        result[i] = dataView.getInt32(byteOffset + i * componentTypeByteLength, true);
                    }
                };
            case ComponentDatatype.UNSIGNED_INT:
                return function (dataView, byteOffset, numberOfComponents, componentTypeByteLength, result) {
                    for (var i = 0; i < numberOfComponents; ++i) {
                        result[i] = dataView.getUint32(byteOffset + i * componentTypeByteLength, true);
                    }
                };
            case ComponentDatatype.FLOAT:
                return function (dataView, byteOffset, numberOfComponents, componentTypeByteLength, result) {
                    for (var i = 0; i < numberOfComponents; ++i) {
                        result[i] = dataView.getFloat32(byteOffset + i * componentTypeByteLength, true);
                    }
                };
            case ComponentDatatype.DOUBLE:
                return function (dataView, byteOffset, numberOfComponents, componentTypeByteLength, result) {
                    for (var i = 0; i < numberOfComponents; ++i) {
                        result[i] = dataView.getFloat64(byteOffset + i * componentTypeByteLength, true);
                    }
                };
        }
    }

    /**
     * A callback function that logs messages.
     * @callback ComponentReader
     *
     * @param {DataView} dataView The data view to read from.
     * @param {Number} byteOffset The byte offset applied when reading from the data view.
     * @param {Number} numberOfComponents The number of components to read.
     * @param {Number} componentTypeByteLength The byte length of each component.
     * @param {Number} result An array storing the components that are read.
     */

    export default getComponentReader;