playcanvas
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Open-source WebGL/WebGPU 3D engine for the web
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JavaScript
/**
* Sampling kernels.
*
* @category Math
*/ class Kernel {
/**
* Generate a set of points distributed in a series of concentric rings around the origin. The
* spacing between points is determined by the number of points in the first ring, and subsequent
* rings maintain this spacing by adjusting their number of points accordingly.
*
* @param {number} numRings - The number of concentric rings to generate.
* @param {number} numPoints - The number of points in the first ring.
* @returns {number[]} An array where each point is represented by two consecutive numbers (x, y).
* @example
* // Generate a kernel with 3 rings and 8 points in the first ring
* const kernel = pc.Kernel.concentric(3, 8);
* // kernel is a flat array: [x0, y0, x1, y1, x2, y2, ...]
*/ static concentric(numRings, numPoints) {
const kernel = [];
// center point
kernel.push(0, 0);
// spacing based on the first ring
const spacing = 2 * Math.PI / numRings / numPoints;
// Generate points for each ring
for(let ring = 1; ring <= numRings; ring++){
const radius = ring / numRings;
const circumference = 2 * Math.PI * radius;
const pointsPerRing = Math.max(1, Math.floor(circumference / spacing));
const angleStep = 2 * Math.PI / pointsPerRing;
for(let point = 0; point < pointsPerRing; point++){
const angle = point * angleStep;
const x = radius * Math.cos(angle);
const y = radius * Math.sin(angle);
kernel.push(x, y);
}
}
return kernel;
}
}
export { Kernel };