/// A 2D drawing made up of straight lines.
struct LineDrawing2D {
    field lines: Line[Point2D];
}

/// A drawing made up of straight lines.
struct LineDrawing[TPoint] {
    field lines: Line[TPoint];
}

/// A straight line from one point to another.
struct Line[TPoint] {
    field start: TPoint;
    field end: TPoint;
}

/// A 2D point.
struct Point2D {
    field x: Int32;
    field y: Int32;
}