[Famicom Party] A quick update
Hello!
Just wanted to send out a quick update to let you know that:
- Yes, I am still working on Chapter 17, but…
- Chapter 17 will now be about object pools, not collision detection.
As I was working on the chapter, I noticed that I was trying to address a huge number of topics all at the same time. It felt confusing to me as I was writing it, and I can only imagine that it would be confusing to readers as well. So, I’m breaking it apart into a few smaller chapters. The thing that feels most important to cover first is object pools - reserved areas in memory that allow you to track state for some number of objects, in our case, enemies and projectiles. The pools are a fixed size, so e.g. once you’ve fired off as many projectiles as the pool has space for, you either need to wait for one of them to go off the screen to open up space, or have the newest projectile take the place of the oldest one. Along the way, we’ll also move some of our code out of NMI and back into the main loop (a.k.a. “forever: JMP forever”) and talk about the “Structure of Arrays” method of storing data, which works very well with the 6502’s indexed addressing capabilities.
So, the plan is to introduce object pools in Chapter 17, and update the space shooter game to add some randomly-spawning enemies and the ability for the player to shoot projectiles (which will pass harmlessly through them). Then, Chapter 18 can focus on detecting collisions between enemies and the player and between player bullets and enemies. A future chapter (possibly Chapter 19, possibly not) can cover detecting collisions between objects and the background, a much more complicated topic but one which is essential for creating the “platformer” games the system is famous for.
Thank you again for reading, and for your patience as I continue working on new content. I am hoping to have Chapter 17 out around the end of April, depending on how much hair-pulling my annual income tax return preparation entails.
Until next time…