Not NaNo Retrospective

Things went well at the start of the month, and I got a lot of work done on the game. In the second half of the month, things started taking longer and started requiring more knowledge of how cocos2d works. I never felt like I understood how exactly cocos2d’s event model worked, because I never did figure out how to have multiple things moving in the game at the same time. There seems like there should have been a way to set up a “do-x-per-tick” way to do events, because it’s common in games, but I never figured out how to do it.

And while I was struggling to get this figured out, I also got sick, which dramatically curtailed my ability to work on the game after the 22nd or so.

I enjoyed working on the game, and I think that doing it sort of like NaNoWriMo also worked well.  One of the big differences I realized is that it’s not really possible to get stuck in NaNo and not know how to proceed. Coming up with a story doesn’t require the tools to be properly understood (assuming you’re not doing it in a text editor with obscure command such as vim or emacs as well as writing), so there’s not really a way to get stuck. Even if the story isn’t going anywhere, you can always move on to the next story.

I think cocos2d is significantly better suited to doing 2D work than Panda3D, which is reasonable, given their focus. I’m glad I didn’t end up using Panda3D. However, cocos2d doesn’t seem to have many examples, the docs are very barebones, and it hasn’t been updated (as of when I wrote this) in 14 months, which is starting to look like an abandoned project.

Would I do it again? Probably. We’ll see next year.


Not NaNo Day 22

I fixed a small bug that kept enemy units from getting targets to attack. It needs some more work, because now the paths generated will go into a core’s safe area, which is something I’d like to avoid. I’ll probably have the enemy choose a different target if this happens, or wander aimlessly/despawn if there aren’t any valid targets.

But I ran into another problem, one which I already sort of knew existed. Two things don’t seem to be able to move at once. They technically can, but there are some weird issues around it. I don’t know if it’s because it’s happening in a subprocess (I’m not sure how cocos2d works this way) or what, but I’ve been unable to figure out exactly how to fix it. Ideally, I’d like some global tick rate, where things are updated every tick. Slower things might be updated some number of ticks, but the concept is the same.

I’m not sure how to do this with cocos2d, or even if it’s possible to do with cocos2d. I spent quite a bit of time trying to get something working, and not coming up with a good solution, so today’s update is a bit light.

cocos2d enemy attack.gif
Enemy appearing to attack a unit. It’s a fluke, not the intended behaviour. In the game it also doesn’t cycle, it goes the one spot and stops.

Not NaNo Day 20

Not much to update today. I started work on enemy movement, but was not able to get it working. I’m starting to duplicate large amounts of code, leading me to wonder if I’m doing things correctly around program structure and event handling.

cocos2d progress 1.PNG
Current progress.

Also, I seem to be doing something else wrong, because the game runs very poorly. Look at the bottom left of the above image. Yes, it is running at 0 FPS (my estimate is more like 0.5 FPS, or worse), which is telling me something is very wrong. Unfortunately, I’m not sure how to profile cocos2d to see if it’s a bottleneck there or in my code, but even for testing, things are unplayably slow, even without enemies attacking and friendly weapons firing on the attacking creeps. I’m not sure how I’ll address this.

Not NaNo Day 19

Including some code cleanup, I fixed the fog-of-war so that it moves with a unit as it moves. It’s not very important, but it was bugging me. I realized that movement of multiple units at the same time is also broken, which I haven’t looked at yet.

cocos2d unit movement fog
Fog of war properly following a unit.

The next thing was starting to implement enemies. The spawning is basic now: enemies spawn close to an enemy controlled core, and they don’t do anything. Making them move, attack and be attackable is the next step (or next few steps).

In future, I want them to spawn more intelligently. Not under safe areas, but near the edges. I’m not sure how to handle making them spawn if large segments of the map are safe, but probably still at the edges.

cocos2d enemy spawn.PNG
Enemies are the red circles. The red hex is an enemy controlled city core. The orange circles are non-functional weapons. 

I’m not sure what the mechanic to take over enemy controlled cores will be. I suspect it will a control network connection and some sort of countdown timer when many enemies rush the core to try to stop the takeover.

Not NaNo Day 18

Today’s task was moving the noise based terrain generation code from my testing branch into the main branch. Once I did this, and fixed a few bugs that cropped up, I also changes the sprites to be normal sized (64×64) versions of the much smaller (8×8) sprites that I’d used in my test. This should mean that, with some tweaks, chunk generation should work in full screen mode as well.

cocos2d terrain noise.PNG
Current state of the game, more or less.


There are still some things to fix, one of the main things being that the start city core can spawn on water. I’m thinking of either making sure it can’t spawn on water, or making it be able to be connected wirelessly and give a free wireless energy (and control whenever I implement that) tower to the player.

Not NaNo Day 17

I spent some more time working on terrain generation, preparing to bring it into the main branch of the game so I can start spawning enemy units. I added a second noise layer to use for not-directly-terrain related sources of randomness, in the game’s case, enemy city-core spawning in chunks.

Enemy city cores randomly distributed and not on water. The closeness they can get to each other is configurable and set to 42 units.

Not NaNo Day 16

Another relatively slow day, programming wise. I did get a first pass of unit movement working. It’s janky and needs more work, but a unit now follows the path set out for it. I think it’d be nice if it followed the path somewhat smoothly rather than teleporting between hexes, but that’s certainly not needed to get a game working.

There weren’t many examples for how to do move a sprite along a path in cocos2d, so I resorted to looking at the source code for how things are done elsewhere. I ended up subclassing the Action class, and implementing the step() function. I’m still not sure how to make the action stop running when I’ve exhausted the path, but it’s a good start. I definitely don’t want to leave the action running forever in the background.

cocos2d unit movement custom action.gif
Basic movement of a unit following the A* shortest path.

Not NaNo Day 15

I worked more on unit movement today. I can now actually make a unit cover the distance between the start and end hex cell, but I haven’t figured out how to make it follow the path I spent all of that time figuring out. Currently, I’m using cocos2d’s MoveBy action to move by a certain amount, and this is certainly the correct start, but I can’t figure out how to do what is essentially enqueuing multiple moves taking place one after another, so that a unit can follow the path between hexes, but smoothly move hex-to-hex.

cocos2d unit movement actions.gif
Movement showing linear sliding. This isn’t what I want, I want it to follow my A* path.

Cocos2d may have support for moving a sprite along an arbitrary paths, and it might for Bezier curves, but the documentation isn’t very clear on it, other than it’s possible existence. I’ll look into how cocos2d supports some of its actions, potentially I need to subclass it and define my own step() function to do one step of my path.

Not NaNo Day 14

Unfortunately, not much to show for today. I spent too much time troubleshooting my A* implementation, and then finally realized that it was all correct except that I was using Python’s PriorityQueue wrong.

cocos2d unit pathfinding.gif
Red outlined hexes showing pathfinding. The tank can pathfind over networks, but has to go around buildings. Code to display was quick and didn’t clear the previous outlines first.

The next step will be using cocos2d’s movement facilities to move the sprite for a unit along the path A* generated. At some point I’ll need to add in the new terrain generation algorithms, so certain units have something interesting to drive around.

Not NaNo Day 13

I started work on basic unit movement, as a start to adding in enemy creeps that defend against. Initially, I’ve made a unit which I’ll call a “hover tank” for now. Movement is simple, it teleports instantly, but I’m going to look into cocos2d’s movement and figure out how to actually have it move over the terrain.

cocos2d unit movement.gif
A unit scouting and pushing back the fog-of-war. I still have that selection error causing the first yellow hex to be mis-selected. Ugh.

Right now, units can be placed on top of networks, but not buildings. This seems reasonable. When it comes time to have them move properly, I may need to figure out how to deal with this. Perhaps all units can be air units and fly over buildings. The other option is to pathfind around buildings, but I was probably going to have units cover the distance directly from the start hex to the end hex. Or I may decide to have it hex pathfind and move hex-by-hex. This won’t use the cocos2d movement system, but it might actually be stylistically better.

Units have a vision area around them, but I may also want to have a safe area around a unit to keep enemy creeps from spawning. Like many things, this will need testing to see what’s fun.