here’s a high-level pseudocode outline to help guide the implementation for adding a snapable grid to the project:
1. Define the grid size and spacing as constants.

const GRID_SIZE = 10;
const GRID_SPACING = 1;

2. Create an additional array gridLines for storing the grid’s line segments.

const gridLines = [];

3. Generate the grid using a function, which populates the gridLines array.

function generateGrid(gridSize, gridSpacing) {
// Generate the grid lines along the X and Z axes.
}

4. In the render function, modify the code so that it renders gridLines separately from the vertices and edges arrays, using a different color or style to distinguish them from the main wireframe lines.
5. When the user tries to create a wireframe line, find the closest grid points for snapping purposes. You can implement this using a function.

function getClosestGridPoint(point, gridSize, gridSpacing) {
// Find the nearest grid vertex to the given point and return it.
}

6. Create a separate wireframeLines array to store the lines created by the user.

const wfLines = [];

7. When a new wireframe line is created, add it to the wireframeLines array and snap its start and end points to the closest grid points.
8. In the render function, draw the wireframeLines separately from the vertices, edges, and gridLines arrays. (also, try improve event listeners, because of performance degradation with time for an unknown reason.):   const canvas = document.createElement('canvas');
canvas.width = window.innerWidth;
canvas.height = window.innerHeight;
document.body.appendChild(canvas);

const ctx = canvas.getContext('2d');
const vmcMenu = document.getElementById('vmc-menu');

const vertices = [
  [0, 0, 0],
...
];

const edges = [
  [0, 1],
...
];

const scale = 0.025;
const zoom = 1;
const offsetX = 0.5;
const offsetY = 0.5;

let angleX = 0;
let angleY = 0;
let angleZ = 0;
  let bestIndex = -1;
  let bestDistance = Infinity;
let startNewEdgeIndex = -1;
let isMouseDown = false;
let prevMousePos = null;

// Red Dot
const redDot = document.getElementById('red-dot');

// Add Edge
document.getElementById('add-edge').addEventListener('click', () => {
  if (bestIndex === -1) return;
  if (startNewEdgeIndex === -1) {
    startNewEdgeIndex = bestIndex;
  } else {
    edges.push([startNewEdgeIndex, bestIndex]);
    startNewEdgeIndex = -1;
  }
});

// Remove Edge
document.getElementById('remove-edge').addEventListener('click', () => {
  if (bestIndex === -1) return;
  edges.forEach((edge, index) => {
    if (edge.includes(bestIndex)) {
      edges.splice(index, 1);
    }
  });
});

function rotateX(angle) {
  const c = Math.cos(angle);
  const s = Math.sin(angle);
  return [
    [1, 0, 0],
    [0, c, -s],
    [0, s, c],
  ];
}

function rotateY(angle) {
  const c = Math.cos(angle);
  const s = Math.sin(angle);
  return [
    [c, 0, s],
    [0, 1, 0],
    [-s, 0, c],
  ];
}

function rotateZ(angle) {
  const c = Math.cos(angle);
  const s = Math.sin(angle);
  return [
    [c, -s, 0],
    [s, c, 0],
    [0, 0, 1],
  ];
}

function project(vertex, scale, offsetX, offsetY, zoom) {
  const [x, y, z] = vertex;
  const posX = (x - offsetX) * scale;
  const posY = (y - offsetY) * scale;
  const posZ = z * scale;

  return [
    (posX * (zoom + posZ) + canvas.width / 2),
    (posY * (zoom + posZ) + canvas.height / 2),
  ];
}

function transform(vertex, rotationMatrix) {
  const [x, y, z] = vertex;
  const [rowX, rowY, rowZ] = rotationMatrix;
  return [
    x * rowX[0] + y * rowX[1] + z * rowX[2],
    x * rowY[0] + y * rowY[1] + z * rowY[2],
    x * rowZ[0] + y * rowZ[1] + z * rowZ[2],
  ];
}

function extraterrestrialTransformation(vertex, frequency, amplitude) {
  const [x, y, z] = vertex;
  const cosX = (Math.cos(x * frequency) * amplitude);
  const cosY = (Math.cos(y * frequency) * amplitude);
  const cosZ = (Math.cos(z * frequency) * amplitude);

  return [x + cosX, y + cosY, z + cosZ];
}

function getDeviation(maxDeviation) {
const t = Date.now() / 1000;
const frequency = 100 / 50;
const amplitude = maxDeviation / 10;
const deviation = Math.sin(t * frequency) * amplitude;
return deviation.toFixed(3);
}

function render() {
  ctx.fillStyle = '#FFF';
  ctx.fillRect(0, 0, canvas.width, canvas.height);

  const rotX = rotateX(angleX);
  const rotY = rotateY(angleY);
  const rotZ = rotateZ(angleZ);

  // Extraterrestrial transformation parameters
  const frequency = 1;
  const amplitude = 0.8;

  const transformedVertices = vertices.map(vertex => {
    const extraterrestrialVertex = extraterrestrialTransformation(vertex, frequency, amplitude);
    const cx = extraterrestrialVertex[0] - offsetX;
    const cy = extraterrestrialVertex[1] - offsetY;
    const cz = extraterrestrialVertex[2] - offsetY;

    const rotated = transform(transform(transform([cx, cy, cz], rotX), rotY), rotZ);

    return [
      rotated[0] + offsetX,
      rotated[1] + offsetY,
      rotated[2] + offsetY,
    ];
  });

  const projectedVertices = transformedVertices.map(vertex => project(vertex, canvas.height * scale, offsetX, offsetY, zoom));

ctx.lineWidth = 2;
ctx.strokeStyle = 'hsla(' + (angleX + offsetX + angleY + offsetY) * 55 + ', 100%, 30%, 0.8)';
ctx.beginPath();

for (let edge of edges) {
const [a, b] = edge;
const [x1, y1] = projectedVertices[a];
const [x2, y2] = projectedVertices[b];

const dist = Math.sqrt((x2 - x1) ** 2 + (y2 - y1) ** 2 + (y2 - x1) ** 2 + (x2 - y1));
const angle = Math.atan2(y2 - y1, x2 - x1, x2 - y1, y2 - x1);

// Calculate control point for curved edge
const cpDist = 0.005 * dist;
const cpX = (x1 + x2) / 2 + cpDist * Math.cos(angle - Math.PI / 2) * getDeviation(0.2);
const cpY = (y1 + y2) / 2 + cpDist * Math.sin(angle - Math.PI / 2) * getDeviation(0.2);

ctx.moveTo(x1, y1, x2, y2);
ctx.quadraticCurveTo(cpX, cpY, x2, y2, x1, y1);
}

ctx.stroke();

canvas.addEventListener('mousedown', (event) => {
  isMouseDown = true;
  prevMousePos = { x: event.clientX, y: event.clientY };
});

canvas.addEventListener('mouseup', () => {
  isMouseDown = false;
  prevMousePos = null;
});

canvas.addEventListener('mousemove', (event) => {
  const mousePos = {
    x: event.clientX - canvas.getBoundingClientRect().left,
    y: event.clientY - canvas.getBoundingClientRect().top
  };
  
  bestIndex = -1;
  bestDistance = Infinity;

  projectedVertices.forEach((currVertex, index) => {
    const distance = Math.hypot(
      currVertex[0] - mousePos.x,
      currVertex[1] - mousePos.y
    );
    if (distance < bestDistance) {
      bestIndex = index;
      bestDistance = distance;
    }
  });
  
  if (bestDistance < 10 && bestIndex !== -1) {
    vmcMenu.style.display = 'block';
    vmcMenu.style.left = mousePos.x + 'px';
    vmcMenu.style.top = mousePos.y + 'px';

    document.getElementById('vmc-vertex-x').value = vertices[bestIndex][0];
    document.getElementById('vmc-vertex-y').value = vertices[bestIndex][1];
    document.getElementById('vmc-vertex-z').value = vertices[bestIndex][2];

    document.getElementById('vmc-vertex-x').dataset.vertexIndex = bestIndex;
    document.getElementById('vmc-vertex-y').dataset.vertexIndex = bestIndex;
    document.getElementById('vmc-vertex-z').dataset.vertexIndex = bestIndex;

    redDot.style.display = 'block';
    redDot.style.left = projectedVertices[bestIndex][0] - 3 + 'px';
    redDot.style.top = projectedVertices[bestIndex][1] - 3 + 'px';
  } else {
    vmcMenu.style.display = 'none';
    redDot.style.display = 'none';
  }

  if (isMouseDown && prevMousePos) {
    const deltaX = event.clientX - prevMousePos.x;
    const deltaY = event.clientY - prevMousePos.y;

    angleY += deltaX * 0.01;
    angleX += deltaY * 0.01;

    prevMousePos = { x: event.clientX, y: event.clientY };
  }
});

function updateVertexValue(event, indexToUpdate) {
  const newValue = parseFloat(event.target.value);
  const vertexIndex = parseInt(event.target.dataset.vertexIndex);

  if (!isNaN(newValue) && vertexIndex >= 0) {
    vertices[vertexIndex][indexToUpdate] = newValue;
  }
}

document.getElementById('vmc-vertex-x').addEventListener('input', (event) => {
  updateVertexValue(event, 0);
});
document.getElementById('vmc-vertex-y').addEventListener('input', (event) => {
  updateVertexValue(event, 1);
});
document.getElementById('vmc-vertex-z').addEventListener('input', (event) => {
  updateVertexValue(event, 2);
});

angleX += +getDeviation(0.0005);
angleY += +getDeviation(0.0005);
angleZ += +getDeviation(0.0005);

  requestAnimationFrame(render);
}

requestAnimationFrame(render);
window.addEventListener("resize", () => {
  canvas.width = window.innerWidth;
  canvas.height = window.innerHeight;
});