A new method for the drawing API: curve offsets

[sgenoud]

This one was more difficult than I thought. I have added a offset method on drawings.

What does that mean? You can now take a 2d drawing a create an offset (i.e. contour). You can even make many of them:

It works as you would expect:

function main() {
  const shape = draw([10, 15])
    .hLine(-5)
    .vLine(5)
    .hLine(20)
    .vLine(-30)
    .hSagittaArc(-15, 3)
    .vLine(5)
    .hSagittaArc(5, -2)
    .close();

  return [
    { shape, color: "black", name: "Base Shape" },
    { shape: shape.offset(-2), color: "blue", name: "Inner offset" },
    { shape: shape.offset(2), color: "red", name: "Outer offset" },
  ];
}

Which draws

Note that there are some known bugs around bezier curves that I need to fix (and I am curious to see how you break it as well!

[sgenoud]

Some more! The logic for offsetting lines was laying the ground work for: fillet and chamfer in 2D. And I went all the way to expose it with two different API.

While drawing

const shape = draw().hLine(10).customCorner(2, 'fillet').vLine(5).close()

on a closed drawing

const shape = draw()
        .hLine(10)
        .vLine(5)
        .close()
        .fillet(2, (e) => e.ofAngle(90))

The first example is nicer when you are drawing a full shape, and the second can be used after some boolean operations have been done, for instance:

  const shape = drawRoundedRectangle(10, 20)
    .fuse(drawCircle(5).translate(5, 10))
    .fuse(drawCircle(3).translate(-3.5, -11));

  const customWithFinder = shape.fillet(2, (e) => e.ofAngle(90));

  return [
    {
      shape: shape,
      name: "Base Shape",
    },
    {
      shape: customWithFinder.translate(20, 0),
      name: "Modified with selectors",
      color: "blue",
    },
  ];

will show something like this

[Papooch]

Shouldn't there be fillets around the smaller circle as well?

[sgenoud]

they are not 90 degrees!