molstar
Version:
A comprehensive macromolecular library.
68 lines (67 loc) • 2.11 kB
JavaScript
;
/**
* Copyright (c) 2019 mol* contributors, licensed under MIT, See LICENSE file for more info.
*
* @author Alexander Rose <alexander.rose@weirdbyte.de>
*/
Object.defineProperty(exports, "__esModule", { value: true });
exports.DefaultCircleProps = void 0;
exports.Circle = Circle;
exports.DefaultCircleProps = {
radius: 1,
segments: 36,
thetaStart: 0,
thetaLength: Math.PI * 2
};
function Circle(props) {
const { radius, segments, thetaStart, thetaLength } = { ...exports.DefaultCircleProps, ...props };
const isFull = thetaLength === Math.PI * 2;
const count = isFull ? segments + 1 : segments + 2;
const vertices = new Float32Array(count * 3);
const normals = new Float32Array(count * 3);
const indices = new Uint32Array(segments * 3);
// center
vertices[0] = 0;
vertices[1] = 0;
vertices[2] = 0;
normals[0] = 0;
normals[1] = 1;
normals[2] = 0;
// vertices & normals
for (let s = 0, i = 3; s < segments; ++s, i += 3) {
const segment = thetaStart + s / segments * thetaLength;
vertices[i] = radius * Math.sin(segment);
vertices[i + 1] = 0;
vertices[i + 2] = radius * Math.cos(segment);
normals[i] = 0;
normals[i + 1] = 1;
normals[i + 2] = 0;
}
// indices
for (let s = 1, i = 0; s < segments; ++s, i += 3) {
indices[i] = s;
indices[i + 1] = s + 1;
indices[i + 2] = 0;
}
if (isFull) {
const j = (segments - 1) * 3;
indices[j] = segments;
indices[j + 1] = 1;
indices[j + 2] = 0;
}
else {
const segment = thetaStart + thetaLength;
const i = (segments + 1) * 3;
vertices[i] = radius * Math.sin(segment);
vertices[i + 1] = 0;
vertices[i + 2] = radius * Math.cos(segment);
normals[i] = 0;
normals[i + 1] = 1;
normals[i + 2] = 0;
const j = (segments - 1) * 3;
indices[j] = segments;
indices[j + 1] = segments + 1;
indices[j + 2] = 0;
}
return { vertices, normals, indices };
}