[Cuis-dev] The Cuis Book for Cuis 6

[Hilaire Fernandes]

Hi Tommy,

You are perfectly right about the inconsistencies you are raising. There 
are related to the genesis of the book and the game example. To prepare 
the book project, I wrote first the game example, then I started writing.
Several weeks later, several chapters were written, Juan took a look to 
the game and told me the Morphic part can be heavily simplified. Indeed 
in the original design I did not use the matrix transformation part of 
every morph (the location attribute you are mentioning is an affine 
transformation matrix) but I was doing the calculus by "hand" with the 
heading attribute. So the game code was simplified, and it was the right 
decision to make. Nevertheless, we did not pay enough attention to the 
already written chapters. I edit the text but I missed some part.

Now that you are raising the issue, I will introduce back #heading and 
#heading: methods. I will keep the heading attribute in the class 
definition chapters (for pedagogical reason), but later will explain it 
is not necessary, so kind of refactor and remove it (it is pedagogical 
too, I think). It will improve the understanding of the code. I will 
edit again the text too.

More comments below.


Le 13/02/2022 à 23:47, Tommy Pettersson via Cuis-dev a écrit :
> I'm not a frequent Cuis user, so I repeated the Spacewar!
> exercise for Cuis 6, and got confused in chapter 4 where
> SpaceShip>>#direction is defined using "location radians"
> before Morphs are even introduced and the SpaceShip is still
> using the "heading" instance variable, so I was expecting
> "^ heading cos @ heading sin".
>
>
> I also have a more dubious suggestion.
>
> One reason I'm redoing the exercise is that the first time
> around I was a bit anoyed that conservation of momentum was
> overlooked, and I want to implement it for the fun of it.

I don't understand fully what you want to do, I should ask to physics 
teachers in my school, but it will be interesting to play with an 
improved version of the game.

> The game already deviates from newtonian physics to be more
> enjoyable -- torpedoes point in the direction of velocity --
> but this is duely mentioned. My suggestion is to briefly
> also mention that a spaceship brought to rotate would
> continue rotating until stopped.

I will be more than happy to add paragraphs you think will improve the 
quality of the book.

Stay tuned for updates.

Thanks

Hilaire

-- 
GNU Dr. Geo
http://drgeo.eu
http://blog.drgeo.eu