molstar
Version:
A comprehensive macromolecular library.
81 lines (80 loc) • 3.64 kB
JavaScript
/**
* Copyright (c) 2018-2020 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 { Vec3 } from '../../../../mol-math/linear-algebra';
import { ChunkedArray } from '../../../../mol-data/util';
// avoiding namespace lookup improved performance in Chrome (Aug 2020)
const v3fromArray = Vec3.fromArray;
const v3magnitude = Vec3.magnitude;
const v3sub = Vec3.sub;
const v3add = Vec3.add;
const v3scale = Vec3.scale;
const v3negate = Vec3.negate;
const v3copy = Vec3.copy;
const v3cross = Vec3.cross;
const caAdd3 = ChunkedArray.add3;
const caAdd = ChunkedArray.add;
const tA = Vec3();
const tB = Vec3();
const tV = Vec3();
const horizontalVector = Vec3();
const verticalVector = Vec3();
const normalOffset = Vec3();
const positionVector = Vec3();
const normalVector = Vec3();
const torsionVector = Vec3();
/** set arrowHeight = 0 for no arrow */
export function addRibbon(state, controlPoints, normalVectors, binormalVectors, linearSegments, widthValues, heightValues, arrowHeight) {
const { currentGroup, vertices, normals, indices, groups } = state;
const vertexCount = vertices.elementCount;
let offsetLength = 0;
if (arrowHeight > 0) {
v3fromArray(tA, controlPoints, 0);
v3fromArray(tB, controlPoints, linearSegments * 3);
offsetLength = arrowHeight / v3magnitude(v3sub(tV, tB, tA));
}
for (let i = 0; i <= linearSegments; ++i) {
const width = widthValues[i];
const height = heightValues[i];
const actualHeight = arrowHeight === 0 ? height : arrowHeight * (1 - i / linearSegments);
const i3 = i * 3;
v3fromArray(verticalVector, normalVectors, i3);
v3scale(verticalVector, verticalVector, actualHeight);
v3fromArray(horizontalVector, binormalVectors, i3);
v3scale(horizontalVector, horizontalVector, width);
if (arrowHeight > 0) {
v3fromArray(tA, normalVectors, i3);
v3fromArray(tB, binormalVectors, i3);
v3scale(normalOffset, v3cross(normalOffset, tA, tB), offsetLength);
}
v3fromArray(positionVector, controlPoints, i3);
v3fromArray(normalVector, normalVectors, i3);
v3fromArray(torsionVector, binormalVectors, i3);
v3add(tA, positionVector, verticalVector);
v3negate(tB, torsionVector);
caAdd3(vertices, tA[0], tA[1], tA[2]);
caAdd3(normals, tB[0], tB[1], tB[2]);
v3sub(tA, positionVector, verticalVector);
caAdd3(vertices, tA[0], tA[1], tA[2]);
caAdd3(normals, tB[0], tB[1], tB[2]);
v3add(tA, positionVector, verticalVector);
v3copy(tB, torsionVector);
caAdd3(vertices, tA[0], tA[1], tA[2]);
caAdd3(normals, tB[0], tB[1], tB[2]);
v3sub(tA, positionVector, verticalVector);
caAdd3(vertices, tA[0], tA[1], tA[2]);
caAdd3(normals, tB[0], tB[1], tB[2]);
}
for (let i = 0; i < linearSegments; ++i) {
caAdd3(indices, vertexCount + i * 4, vertexCount + (i + 1) * 4 + 1, vertexCount + i * 4 + 1);
caAdd3(indices, vertexCount + i * 4, vertexCount + (i + 1) * 4, vertexCount + (i + 1) * 4 + 1);
caAdd3(indices, vertexCount + i * 4 + 2 + 1, vertexCount + (i + 1) * 4 + 2 + 1, vertexCount + i * 4 + 2);
caAdd3(indices, vertexCount + i * 4 + 2, vertexCount + (i + 1) * 4 + 2 + 1, vertexCount + (i + 1) * 4 + 2);
}
const addedVertexCount = (linearSegments + 1) * 4;
for (let i = 0, il = addedVertexCount; i < il; ++i)
caAdd(groups, currentGroup);
}