119 lines
2.7 KiB
TypeScript
119 lines
2.7 KiB
TypeScript
import { canvas2d } from "./lib/html";
|
|
import { Prng, mulberry32 } from "./lib/prng";
|
|
|
|
const BLOWUP = 4;
|
|
const WIDTH = 240;
|
|
const HEIGHT = 135;
|
|
|
|
type Lookup2d = (x: number, y: number) => number;
|
|
function dim(width: number, height: number): Lookup2d {
|
|
return function xy(x: number, y: number) {
|
|
return (
|
|
(((x % width) + width) % width) +
|
|
width * (((y % height) + height) % height)
|
|
);
|
|
};
|
|
}
|
|
|
|
class IslandGrid {
|
|
data: number[];
|
|
rng: Prng;
|
|
|
|
xy: Lookup2d;
|
|
|
|
constructor(public width: number, public height: number, seed: number) {
|
|
this.data = Array(width * height).fill(0);
|
|
this.rng = mulberry32(seed);
|
|
this.xy = dim(width, height);
|
|
}
|
|
|
|
public get(x: number, y: number): number {
|
|
return this.data[this.xy(x, y)];
|
|
}
|
|
|
|
public set(x: number, y: number, tile: number) {
|
|
this.data[this.xy(x, y)] = tile;
|
|
console.log(x, y, this.xy(x, y), this.data[this.xy(x, y)]);
|
|
}
|
|
|
|
public floodSearch(
|
|
startPos: number,
|
|
shouldExpand: (tile: number) => boolean
|
|
): number[] {
|
|
const len = this.data.length;
|
|
const width = this.width;
|
|
const seen = new Uint8Array(len);
|
|
|
|
const hitPositions: number[] = [];
|
|
|
|
function enqueue(pos: number) {
|
|
if (!seen[pos]) {
|
|
hitPositions.push(pos);
|
|
seen[pos] = 1;
|
|
}
|
|
}
|
|
|
|
enqueue(startPos);
|
|
|
|
for (let i = 0; i < hitPositions.length; i++) {
|
|
const pos = hitPositions[i];
|
|
if (shouldExpand(this.data[pos])) {
|
|
enqueue((pos - width) % len);
|
|
enqueue((pos - 1) % len);
|
|
enqueue((pos + 1) % len);
|
|
enqueue((pos + width) % len);
|
|
}
|
|
}
|
|
|
|
return hitPositions;
|
|
}
|
|
}
|
|
|
|
function renderIslands(islands: IslandGrid, cx: CanvasRenderingContext2D) {
|
|
for (let y = 0; y < islands.height; y++) {
|
|
for (let x = 0; x < islands.width; x++) {
|
|
const tile = islands.data[islands.xy(x, y)];
|
|
switch (tile) {
|
|
case 0:
|
|
cx.fillStyle = "blue";
|
|
break;
|
|
case 1:
|
|
cx.fillStyle = "yellow";
|
|
break;
|
|
case 2:
|
|
cx.fillStyle = "#00ff00";
|
|
break;
|
|
case 3:
|
|
cx.fillStyle = "#008800";
|
|
break;
|
|
default:
|
|
cx.fillStyle = "#666666";
|
|
break;
|
|
}
|
|
cx.fillRect(x, y, 1, 1);
|
|
}
|
|
}
|
|
}
|
|
|
|
export function IslandApplet() {
|
|
const [canvas, cx] = canvas2d({
|
|
width: WIDTH * BLOWUP,
|
|
height: HEIGHT * BLOWUP,
|
|
});
|
|
cx.scale(BLOWUP, BLOWUP);
|
|
|
|
const islands = new IslandGrid(WIDTH, HEIGHT, 128);
|
|
const x = islands.rng();
|
|
const y = islands.rng();
|
|
|
|
islands.set(x, y, 1);
|
|
islands
|
|
.floodSearch(islands.xy(x, y), (tile) => tile > 0)
|
|
.forEach((pos) => islands.data[pos]++);
|
|
|
|
renderIslands(islands, cx);
|
|
|
|
return [canvas];
|
|
}
|
|
|
|
(globalThis as any).IslandApplet = IslandApplet;
|