Function polygonise 

pub fn polygonise(
    grid_cell: GridCell,
    isolevel: f32,
    triangles: &mut [Triangle],
) -> i32

Polygonises a grid cell based on the given isolevel, populating the given triangles slice with the resulting triangles.

Parameters

• grid_cell: A GridCell struct representing the cell to be polygonised. It contains the positions of the cell’s vertices and their values.
• isolevel: A float value representing the isolevel to use when determining which parts of the cell are inside and outside the surface. The isolevel separates the grid cell into parts that are either inside or outside the surface being represented.
• triangles: A mutable slice of Triangle structs to be filled with the resulting triangles. The triangles are generated by triangulating the parts of the grid cell that are inside the surface.

Returns

The number of triangles generated, as an i32.

Example

use iso::{GridCell, Triangle, polygonise};

let grid_cell = GridCell {
    positions: [
        [0.0, 0.0, 0.0],
        [1.0, 0.0, 0.0],
        [1.0, 1.0, 0.0],
        [0.0, 1.0, 0.0],
        [0.0, 0.0, 1.0],
        [1.0, 0.0, 1.0],
        [1.0, 1.0, 1.0],
        [0.0, 1.0, 1.0]
    ],
    value: [0.0, 0.5, 0.5, 1.0, 0.0, 1.0, 1.0, 0.0],
};
let mut triangles = vec![];

let isolevel = 0.5;
let result = polygonise(grid_cell, isolevel, &mut triangles);

assert_eq!(result, 4);