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Diffstat (limited to 'web/pw-visualizer/src/voronoi/voronoi.ts')
| -rw-r--r-- | web/pw-visualizer/src/voronoi/voronoi.ts | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/web/pw-visualizer/src/voronoi/voronoi.ts b/web/pw-visualizer/src/voronoi/voronoi.ts new file mode 100644 index 0000000..a63bc9a --- /dev/null +++ b/web/pw-visualizer/src/voronoi/voronoi.ts @@ -0,0 +1,165 @@ +import type { Shader } from "../webgl/shader"; +import type { BBox, Point } from "./voronoi-core"; +import Voronoi from "./voronoi-core"; +import { DefaultRenderable } from "../webgl/renderer"; +import { IndexBuffer, VertexBuffer } from "../webgl/buffer"; +import { VertexBufferLayout, VertexArray } from "../webgl/vertexBufferLayout"; + +function arcctg(x: number): number { return Math.PI / 2 - Math.atan(x); } + +function to_key(p: Point): string { + return [p.x, p.y] + ""; +} + +function round_point(center: Point, point: Point, amount_fn = (b: number) => 0.7): Point { + const d = dist(center, point, true); + const x = center.x + amount_fn(d) * (point.x - center.x); + const y = center.y + amount_fn(d) * (point.y - center.y); + return { 'x': x, 'y': y }; +} + +function median_point(c: Point, p: Point, n: Point, d = 0.1): number[] { + const dd = 1.0 - 2 * d; + return [ + dd * c.x + d * p.x + d * n.x, + dd * c.y + d * p.y + d * n.y, + ] +} + +function build_point_map(es: Voronoi.HalfEdge[]): (point: Point) => Point { + const mean = es.map(e => dist(e.getStartpoint(), e.getEndpoint())).reduce((a, b) => a + b, 0) / es.length; + const map = {}; + + for (let edge of es) { + const start = edge.getStartpoint(); + const end = edge.getEndpoint(); + + if (dist(start, end) < 0.03 * mean) { // These points have to be merged + const middle = { 'x': (start.x + end.x) / 2, 'y': (start.y + end.y) / 2 }; + map[to_key(start)] = middle; + map[to_key(end)] = middle; + } + } + + return (p) => map[to_key(p)] || p; +} + +function get_round_fn(dist_mean: number, amount = 0.7): (d: number) => number { + return (d) => arcctg((d - dist_mean) / dist_mean) / Math.PI + 0.6; +} + +function dist(a: Point, b: Point, norm = false): number { + const dx = a.x - b.x; + const dy = a.y - b.y; + if (norm) return Math.sqrt(dx * dx + dy * dy); + return dx * dx + dy * dy; +} + +export class VoronoiBuilder { + inner: DefaultRenderable; + + vor: Voronoi; + planets: Point[]; + + + constructor(gl: WebGLRenderingContext, shader: Shader, planets: Point[], bbox: BBox) { + this.vor = new Voronoi(); + this.planets = planets; + + const ib = new IndexBuffer(gl, []); + const vb = new VertexBuffer(gl, []); + + const layout = new VertexBufferLayout(); + layout.push(gl.FLOAT, 2, 4, "a_pos"); + layout.push(gl.FLOAT, 2, 4, "a_center"); + layout.push(gl.FLOAT, 1, 4, "a_own"); + layout.push(gl.FLOAT, 1, 4, "a_intensity"); + + const vao = new VertexArray(); + vao.addBuffer(vb, layout); + + this.inner = new DefaultRenderable(ib, vao, shader, [], {}); + + this.resize(gl, bbox); + } + + getRenderable(): DefaultRenderable { + return this.inner; + } + + resize(gl: WebGLRenderingContext, bbox: BBox) { + const start = new Date().getTime(); + + // This voronoi sorts the planets, then owners don't align anymore + const own_map = {}; + this.planets.forEach((p, i) => own_map[to_key(p)] = i); + + const vor = this.vor.compute(this.planets, bbox); + + const attrs = []; + const ids = []; + + let vertCount = 0; + + for (let i = 0; i < vor.cells.length; i++) { + const cell = vor.cells[i]; + const planetId = own_map[to_key(cell.site)]; + const point_map = build_point_map(cell.halfedges); + + const centerId = vertCount++; + + attrs.push(cell.site.x, cell.site.y); + attrs.push(cell.site.x, cell.site.y); + attrs.push(planetId); + attrs.push(1); + + const dist_mean = cell.halfedges.map(e => { + const start = e.getStartpoint(); + const end = e.getEndpoint(); + return dist(cell.site, start, true) + dist(cell.site, { 'x': (start.x + end.x) / 2, 'y': (start.y + end.y) / 2 }, true) + }).reduce((a, b) => a + b, 0) / cell.halfedges.length / 2; + const round_fn = get_round_fn(dist_mean); + + for (let edge of cell.halfedges) { + let start = point_map(edge.getStartpoint()); + let end = point_map(edge.getEndpoint()); + let center = { 'x': (start.x + end.x) / 2, 'y': (start.y + end.y) / 2 }; + + if (to_key(start) == to_key(end)) continue; + + start = round_point(cell.site, start, round_fn); + center = round_point(cell.site, center, round_fn); + end = round_point(cell.site, end, round_fn); + + ids.push(centerId); + ids.push(vertCount++); + attrs.push(start.x, start.y); + attrs.push(cell.site.x, cell.site.y); + attrs.push(planetId); + attrs.push(0); + + ids.push(vertCount++); + attrs.push(center.x, center.y); + attrs.push(cell.site.x, cell.site.y); + attrs.push(planetId); + attrs.push(0); + + ids.push(centerId); + ids.push(vertCount - 1); + + ids.push(vertCount++); + attrs.push(end.x, end.y); + attrs.push(cell.site.x, cell.site.y); + attrs.push(planetId); + attrs.push(0); + } + } + + this.inner.updateIndexBuffer(gl, ids); + this.inner.updateVAOBuffer(gl, 0, attrs); + + console.log(`Vor things took ${new Date().getTime() - start} ms!`) + } +} + +export default VoronoiBuilder;
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