molstar
Version:
A comprehensive macromolecular library.
47 lines (46 loc) • 2.2 kB
JavaScript
/**
* Copyright (c) 2019 mol* contributors, licensed under MIT, See LICENSE file for more info.
*
* @author Alexander Rose <alexander.rose@weirdbyte.de>
* @author David Sehnal <david.sehnal@gmail.com>
*/
import { readCcp4Header, readCcp4Slices, getCcp4DataOffset, getCcp4ValueType } from '../../../../mol-io/reader/ccp4/parser';
import { getCcp4Origin } from '../../../../mol-model-formats/volume/ccp4';
async function readHeader(name, file) {
const { header: ccp4Header, littleEndian } = await readCcp4Header(file);
const header = {
name,
valueType: getCcp4ValueType(ccp4Header),
grid: [ccp4Header.NX, ccp4Header.NY, ccp4Header.NZ],
axisOrder: [ccp4Header.MAPC, ccp4Header.MAPR, ccp4Header.MAPS].map(i => i - 1),
extent: [ccp4Header.NC, ccp4Header.NR, ccp4Header.NS],
origin: getCcp4Origin(ccp4Header),
spacegroupNumber: ccp4Header.ISPG,
cellSize: [ccp4Header.xLength, ccp4Header.yLength, ccp4Header.zLength],
cellAngles: [ccp4Header.alpha, ccp4Header.beta, ccp4Header.gamma],
littleEndian,
dataOffset: getCcp4DataOffset(ccp4Header),
originalHeader: ccp4Header
};
// "normalize" the grid axis order
header.grid = [header.grid[header.axisOrder[0]], header.grid[header.axisOrder[1]], header.grid[header.axisOrder[2]]];
return header;
}
export async function readSlices(data) {
const { slices, header } = data;
if (slices.isFinished) {
return;
}
const { extent, originalHeader } = header;
const sliceSize = extent[0] * extent[1];
const sliceByteOffset = slices.buffer.elementByteSize * sliceSize * slices.slicesRead;
const sliceCount = Math.min(slices.sliceCapacity, extent[2] - slices.slicesRead);
const sliceByteCount = slices.buffer.elementByteSize * sliceCount * sliceSize;
await readCcp4Slices(originalHeader, slices.buffer, data.file, header.dataOffset + sliceByteOffset, sliceByteCount, header.littleEndian);
slices.slicesRead += sliceCount;
slices.sliceCount = sliceCount;
if (slices.slicesRead >= extent[2]) {
slices.isFinished = true;
}
}
export const Ccp4Provider = { readHeader, readSlices };