molstar
Version:
A comprehensive macromolecular library.
65 lines (64 loc) • 2.9 kB
JavaScript
/**
* Copyright (c) 2018-2020 mol* contributors, licensed under MIT, See LICENSE file for more info.
*
* Taken/adapted from DensityServer (https://github.com/dsehnal/DensityServer)
*
* @author David Sehnal <david.sehnal@gmail.com>
* @author Alexander Rose <alexander.rose@weirdbyte.de>
*/
import { SimpleBuffer } from '../../mol-io/common/simple-buffer';
export var TypedArrayValueType;
(function (TypedArrayValueType) {
TypedArrayValueType.Float32 = 'float32';
TypedArrayValueType.Int8 = 'int8';
TypedArrayValueType.Int16 = 'int16';
TypedArrayValueType.Uint16 = 'uint16';
})(TypedArrayValueType || (TypedArrayValueType = {}));
export function getElementByteSize(type) {
if (type === TypedArrayValueType.Float32)
return 4;
if (type === TypedArrayValueType.Int16)
return 2;
if (type === TypedArrayValueType.Uint16)
return 2;
return 1;
}
export function makeTypedArray(type, buffer, byteOffset = 0, length) {
if (type === TypedArrayValueType.Float32)
return new Float32Array(buffer, byteOffset, length);
if (type === TypedArrayValueType.Int16)
return new Int16Array(buffer, byteOffset, length);
if (type === TypedArrayValueType.Uint16)
return new Uint16Array(buffer, byteOffset, length);
return new Int8Array(buffer, byteOffset, length);
}
export function createTypedArray(type, size) {
switch (type) {
case TypedArrayValueType.Float32: return new Float32Array(new ArrayBuffer(4 * size));
case TypedArrayValueType.Int8: return new Int8Array(new ArrayBuffer(1 * size));
case TypedArrayValueType.Int16: return new Int16Array(new ArrayBuffer(2 * size));
case TypedArrayValueType.Uint16: return new Uint16Array(new ArrayBuffer(2 * size));
}
throw Error(`${type} is not a supported value format.`);
}
export function createTypedArrayBufferContext(size, type) {
const elementByteSize = getElementByteSize(type);
const arrayBuffer = new ArrayBuffer(elementByteSize * size);
const readBuffer = SimpleBuffer.fromArrayBuffer(arrayBuffer);
const valuesBuffer = SimpleBuffer.IsNativeEndianLittle ? arrayBuffer : new ArrayBuffer(elementByteSize * size);
return {
type,
elementByteSize,
readBuffer,
valuesBuffer: new Uint8Array(valuesBuffer),
values: makeTypedArray(type, valuesBuffer)
};
}
export async function readTypedArray(ctx, file, position, byteCount, valueByteOffset, littleEndian) {
await file.readBuffer(position, ctx.readBuffer, byteCount, valueByteOffset);
if (ctx.elementByteSize > 1 && ((littleEndian !== void 0 && littleEndian !== SimpleBuffer.IsNativeEndianLittle) || !SimpleBuffer.IsNativeEndianLittle)) {
// fix the endian
SimpleBuffer.flipByteOrder(ctx.readBuffer, ctx.valuesBuffer, byteCount, ctx.elementByteSize, valueByteOffset);
}
return ctx.values;
}