Tracking and Placing a Pentomino

The Shape constructor takes in a rotation, reflection, and location value and returns the struct that represents the orientation and location of that shape on the board. This rotation, reflection, and location will be the result of a user selecting a shape and moving it around the board before finally dropping it into place. A user may do any combination of rotating the shape, reflecting the shape, or moving it up and down on the board before deciding to place it. So, we need a way to track all of these user inputs in one place before feeding the final rotation, reflection, and location values into our Shape constructor. We’ll implement the Pentomino module to do exactly that.

Like the Shape module, the Pentomino module will produce structs that know the shape name, rotation, reflection, and location. Most importantly, however, the Pentomino module will implement a series of reducers that we can string together given a set of user inputs to change the rotation, reflection, and location of the pentomino. Then, the pentomino will be converted into a shape in order to be placed on the board at the correct set of points.

If you’re thinking that this process—creating a Pentomino struct, transforming it with a series of reducers, and then converting it into a shape that can be displayed to the user—sounds a lot like CRC, you’d be right!

Let’s implement our new module.