@polygonjs/polygonjs
Version:
node-based WebGL 3D engine https://polygonjs.com
70 lines (69 loc) • 2.28 kB
JavaScript
;
import { Vector2, BufferGeometry, BufferAttribute } from "three";
const stepSize = new Vector2();
const stepsCount = new Vector2();
export class CoreGeometryOperationHexagon {
constructor(_size, _hexagonRadius, _pointsOnly) {
this._size = _size;
this._hexagonRadius = _hexagonRadius;
this._pointsOnly = _pointsOnly;
}
process() {
const sideLength = this._hexagonRadius;
const halfSideLength = sideLength * 0.5;
stepSize.set(sideLength, Math.cos(Math.PI / 6) * this._hexagonRadius);
stepsCount.set(Math.floor(this._size.x / stepSize.x), Math.floor(this._size.y / stepSize.y));
let positions = [];
let indices = [];
const addIndices = !this._pointsOnly;
for (let y = 0; y < stepsCount.y; y++) {
for (let x = 0; x < stepsCount.x; x++) {
positions.push(
-(this._size.x * 0.5) + x * stepSize.x + (y % 2 == 0 ? halfSideLength : 0),
-(this._size.y * 0.5) + y * stepSize.y,
0
);
if (addIndices) {
if (y >= 1) {
if (x == 0 || x == stepsCount.x - 1) {
if (x == 0) {
} else {
}
} else {
if (y % 2 == 0) {
indices.push(
x + y * stepsCount.x,
x - 1 + y * stepsCount.x,
x + (y - 1) * stepsCount.x
);
indices.push(
x + y * stepsCount.x,
x + (y - 1) * stepsCount.x,
x + 1 + (y - 1) * stepsCount.x
);
} else {
indices.push(
x + (y - 1) * stepsCount.x,
x + y * stepsCount.x,
x - 1 + (y - 1) * stepsCount.x
);
indices.push(
x + 1 + y * stepsCount.x,
x + y * stepsCount.x,
x + (y - 1) * stepsCount.x
);
}
}
}
}
}
}
const geometry = new BufferGeometry();
geometry.setAttribute("position", new BufferAttribute(new Float32Array(positions), 3));
if (addIndices) {
geometry.setIndex(indices);
geometry.computeVertexNormals();
}
return geometry;
}
}