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diff --git a/src/Terrain.js b/src/Terrain.js
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-'use strict';
-
-import Voronoi from './3rdparty/rhill-voronoi-core.js';
-
-import { lerp, clamp, useAverage } from './modules/Util.js';
-import { dist, AABB, QuadTree } from './modules/Geometry.js';
-
-
-/* from here on up, we always assume that points live in the range [(0,0), (1,1)) */
-
-function lloydRelax(point_set, density) {
- /* setup quadtree and averages */
- let tree = new QuadTree(1,1);
- let averages = {};
- for (let i=0; i<point_set.length; i++) {
- const point = point_set[i];
- point.index = i;
- tree.insert(point);
-
- let [avg, append] = useAverage();
- const cent_x = { avg, append };
- [avg, append] = useAverage();
- const cent_y = { avg, append };
- averages[i] = { cent_x, cent_y };
- }
-
- /* compute average centroids */
- for (let x=0; x<1; x += 1/density) {
- for (let y=0; y<1; y += 1/density) {
- const point = { x, y };
- const closest = tree.closest(point);
- const { cent_x, cent_y } = averages[closest.index];
- cent_x.append(point.x);
- cent_y.append(point.y);
- }
- }
-
- /* return centroid points */
- const result = [];
- for (let i=0; i<point_set.length; i++) {
- const point = { x: averages[i].cent_x.avg(), y: averages[i].cent_y.avg() };
- result.push(point);
- }
- return result;
-}
-
-
-class Terrain {
- constructor() {
- const N_SEED_POINTS = 2**12;
- const N_RELAX_ITERATIONS = 1;
- const RELAX_DENSITY = 400;
- const randomPoint = () => ({x: Math.random(), y: Math.random()});
-
- this.min_height = 0;
- this.max_height = 0;
-
- let seed_points = [];
- for (let i=0; i<N_SEED_POINTS; i++) seed_points.push(randomPoint());
-
- for (let i=0; i<N_RELAX_ITERATIONS; i++)
- lloydRelax(seed_points, RELAX_DENSITY);
-
- const v = new Voronoi();
- this.voronoi = v.compute(seed_points, {xl: 0, xr: 1, yt: 0, yb: 1});
-
- this.tree = new QuadTree(1,1);
- let index = 0;
- for (let v of this.voronoi.vertices) {
- v.height = v.y;
- v.index = index;
- index += 1;
- this.tree.insert(v);
- }
-
- this.graph = {};
- for (let e of this.voronoi.edges) {
- if (!this.graph[e.va.index]) this.graph[e.va.index] = new Set();
- if (!this.graph[e.vb.index]) this.graph[e.vb.index] = new Set();
-
- this.graph[e.va.index].add(e.vb.index);
- this.graph[e.vb.index].add(e.va.index);
- }
- }
-
-
- applyBrush(x, y, f, strength, radius) {
- const region = new AABB(x-radius, y-radius, 2*radius, 2*radius);
- const points = this.tree.root.getPointsInRegion(region);
-
- const dist2 = (a, b) => (a.x - b.x)**2 + (a.y - b.y)**2;
-
- const sigma = radius/3;
- const beta = 1/(2*sigma*sigma);
- const center = { x, y };
- const power = pt => Math.exp(-beta * dist2(pt, center));
-
- for (let pt of points) f(pt, strength * power(pt));
- }
-
-
- getNeighbors(point) {
- const indices = Array.from(this.graph[point.index]);
- return indices.map( index => this.voronoi.vertices[index] );
- }
-
-
- renderGrid(ct) {
- ct.save();
- ct.lineWidth = 0.001;
- for (let edge of this.voronoi.edges) {
- ct.fillStyle = `hsl(${edge.va.height}, 100%, 50%)`;
- ct.beginPath();
- ct.arc(edge.va.x, edge.va.y, 0.0005, 0, 2*Math.PI);
- ct.closePath();
- ct.fill();
-
- /*ct.beginPath();
- ct.moveTo(edge.va.x, edge.va.y);
- ct.lineTo(edge.vb.x, edge.vb.y);
- ct.closePath();
- ct.stroke();
- */
- }
- ct.restore();
- }
-
- render(ct) {
- function rgb(r, g, b) {
- this.r = r; this.g = g; this.b = b;
- }
- const renderRgb = rgb => `rgb(${rgb.r}, ${rgb.g}, ${rgb.b})`;
- const lerpColors = (a, b, alpha) => new rgb(
- lerp(a.r, b.r, alpha),
- lerp(a.g, b.g, alpha),
- lerp(a.b, b.b, alpha)
- );
- const getBucket = (value, min, max, numBuckets) => {
- const delta = max - min;
- const step = delta/numBuckets;
- return clamp(Math.floor((value-min)/step), 0, numBuckets-1);
- }
- const getColor = (value, min, max, colors) => {
- if (value < min) return colors[0];
- if (value >= max) return colors[colors.length-1];
-
- const step = (max - min)/(colors.length - 1);
-
- const index = getBucket(value, min, max, colors.length-1);
- const alpha = (value - (index*step) - min)/step;
- const color = lerpColors(
- colors[index], colors[index+1],
- alpha
- );
- if (color.r <= 0)
- console.log(value, index, alpha, color);
- return color;
- }
-
- const colors = [
- /* ocean */
- new rgb(31, 59, 68),
- new rgb(68, 130, 149),
-
- /* land */
- new rgb(229, 199, 169),
- new rgb(198, 133, 67),
- new rgb(117, 89, 61),
-
- /* mountain */
- new rgb(82, 74, 64),
- new rgb(82, 74, 64),
- new rgb(255, 255, 255),
- ];
- ct.save();
-
- for (let cell of this.voronoi.cells) {
- ct.beginPath();
-
- let height = 0;
- let count = 1;
- for (let edge of cell.halfedges) {
- const p0 = edge.getStartpoint();
- const p1 = edge.getEndpoint();
- height += p0.height;
- count += 1;
- ct.lineTo(p0.x, p0.y);
- ct.lineTo(p1.x, p1.y);
- }
- ct.closePath();
- height /= count;
- height = 10 * Math.floor(height/10);
- const color = getColor(height, 0, 100, colors);
- if (color.r <=0) console.log(color);
- ct.fillStyle = renderRgb(color);
- ct.strokeStyle = renderRgb(color);
- ct.stroke();
- ct.fill();
- }
-
- ct.restore();
- }
-}
-
-export { lloydRelax };
-export default Terrain;