dotSCAD/docs/lib2x-ptf_torus.md

# ptf_torus

Transforms a point inside a rectangle to a point of a torus. It can create things such as [torus maze](https://github.com/JustinSDK/dotSCAD/blob/master/examples/maze/torus_maze.scad).

![ptf_torus](images/lib2x-ptf_torus-1.JPG)

**Since:** 2.3

## Parameters

- `size` : 2 value array `[x, y]`, rectangle with dimensions `x` and `y`.
- `point` : The point to be transformed.
- `radius` : Torus `[R, r]`.
- `angle` : Torus `[A, a]`.
- `twist` : The number of degrees of through which the rectangle is twisted.

## Examples

    use <hull_polyline3d.scad>;
    use <ptf/ptf_torus.scad>;

    size = [20, 10];
    radius = [10, 5];
    angle = [180, 180];
    twist = 90;

    rows = [
        for(y = [0:size[1]])
            [for(x = [0:size[0]]) [x, y]]
    ];

    columns = [
        for(x = [0:size[0]])
            [for(y = [0:size[1]]) [x, y]]
    ];

    for(line = rows) {
        transformed = [for(p = line) ptf_torus(size, p, radius, angle, twist)];
        hull_polyline3d(transformed, thickness = .5);
    }

    for(line = columns) {
        transformed = [for(p = line) ptf_torus(size, p, radius, angle, twist)];
        hull_polyline3d(transformed, thickness = .5);
    }

![ptf_torus](images/lib2x-ptf_torus-2.JPG)