2025-01-06 14:28:47 +11:00

82 lines
1.8 KiB
JavaScript

// calculate tiles
const RADIUS_OPTS = [
"const",
"right",
"left",
"up",
"down",
"right-up",
"right-down",
"left-up",
"left-down",
"in",
"out",
];
function distance(dx, dy) {
return Math.sqrt(dx ** 2 + dy ** 2);
}
class DotMaker {
constructor(width) {
this.width = width;
this.cx = 0.5 * width;
this.cy = 0.5 * width;
}
dots(m, n) {
if( m - n === 0 ) {
return [];
}
const ps = [];
const imin = -this.width;
const imax = this.width / m;
for( let i = imin; i <= imax; i++ ) {
const jmin = m * i + (m - n) * this.width;
const jmax = m * i;
for( let j = jmin; j <= jmax; j++ ) {
const x = (j - m * i) / (m - n);
const y = m * (x + i);
if( x > 0 && y > 0 && x < this.width && y < this.width ) {
ps.push({i:i, j:j, x:x, y:y});
}
}
}
return ps;
}
radius(d, func, maxr) {
switch (func) {
case "const":
return maxr;
case "right":
return maxr * d.x / this.width;
case "left":
return maxr * (this.width - d.x) / this.width;
case "down":
return maxr * d.y / this.width;
case "up":
return maxr * (this.width - d.y) / this.width;
case "right-up":
return 0.5 * maxr * (d.x + this.width - d.y) / this.width;
case "left-up":
return 0.5 * maxr * (this.width - d.x + this.width - d.y) / this.width;
case "right-down":
return 0.5 * maxr * (d.x + d.y) / this.width;
case "left-down":
return 0.5 * maxr * (this.width - d.x + d.y) / this.width;
case "out":
return 2 * maxr * distance((d.x - this.cx), (d.y - this.cy)) / this.width;
case "in":
return 2 * maxr * (0.5 * this.width - distance((d.x - this.cx), (d.y - this.cy))) / this.width;
default:
return maxr;
}
}
}
export { RADIUS_OPTS, DotMaker };