Game Development Game Jams Software Development

Ludum Dare 41 Postmortem

Ludum Dare 41 came to an end just a little more than a week ago. I believe I’ve finally recovered from the mayhem and come through the better in the end.

Project Status

Unfortunately, my Ludum Dare 41 project, a “turn-based AI battle-royale game” called “Turn-by-Turn Deathmatch” was not finished when the 72-hour deadline hit. This was, unfortunately, my expectation for this one. I may continue working on the game in the future, but I am particularly averse to the theme and not satisfied with the idea that I was able to come up with.

The Theme

My struggle for this Ludum Dare originated at the outset of the theme announcement. The theme for 41 was “combine two incompatible genres.” I know a lot of people had differing opinions on this, but it is mine that it is the worst theme yet. For those of us that are relatively new to the game-design scene, the theme is asking us to throw out any convention of design that we may have relied upon to make a game that is not a complete flop. For those more experienced, I will grant that it does provide a unique challenge, and for that reason I was almost somewhat conflicted. That said, it is my opinion that Ludum Dare should be welcoming to new developers, as Ludum Dare is often some of the first exposures to the indie game dev scene that they will get. It should be a good impression. I believe this theme, by significantly raising the difficulty of creating a workable concept, likely created a bad first experience for them.

I created a very large, very time-costly spreadsheet of an incomplete list of game genres in an adjacency-martrix-like spreadsheet, which ranked the combination of any two genres as “good,” “neutral,” or “bad” based on how well it fit the theme, which is to say that a “good” combination was two genres that one would not expect to see combined. Even with this chart, I found myself struggling to come up with a theme, because as it turned out, many of the “good” combinations sounded like awful games, or they required some complexity that I knew would take longer than the deadline. For example, I really wanted to do a “first-person platformer,” which would be a 3D game where you basically see something like Super Mario from Mario’s eyes. It’s been done before, and I recall positive reception. Unfortunately, my 3D-focused game engine did not have a completed rendering engine, and with 3D being somewhat new territory for me, I scrapped that idea. Eventually I came up with combining “turn-based” and “shooter” and then eventually I realized that “shooter” could be replaced with “battle-royale” if the enemies are roughly equally equipped and trying to kill each other as well. I thought it was a neat concept, but I also knew that I had minimal experience with AI, and no experience with turn-based games. I was also looking at just over 24 hours left on the deadline when I had the theme nailed down, so I knew it would be a big challenge.

The Technical Struggle

I wanted to go into this jam using my custom 2D game engine, ArcticWolf. I saw this as an opportunity to, as I did last time, use the game jam as a sort of excuse and motivation to further my progress on the mundane core subsystems of my game engines. I had intended to work out a simple painterly blitting rendering engine, because I thought it would be the most straightforward design where the least issues could crop up. What I did not realize, however, was that rendering things in the correct order being mandatory in a painterly renderer, would actually prove to be a nightmare of a challenge.

In C++ there is no STL container that allows indexed access and automatically organizes them based on a comparison. There is a container called std::priority_queue, but that will only provide access to the front element in the queue. This could work if we rebuilt the entire rendering queue every frame, but I knew that would be a huge detriment to the performance of the game, since elements would not be frequently (probably never) changing their z-indices, and therefore what I really wanted was a std::priority_vector.

Well, I hate to break this to you all, but no such thing as std::priority_vector exists. So I made one. In the ArcticWolf code, there is a class called aw::PriorityVector, which does everything that I needed. It took a lot of work, but it is one of the pieces of my creation during this game jam that I am the most proud of. It’s very simple, and all it does is store elements into the vector in the correct order based on a comparison type, the same that you might pass to std::sort. If the attributes defining the comparable values of the contained objects change, there’s a method that allows reordering the entire container, which is expensive, but useful if z-indices change. Another couple of useful helper classes were created to be used with this: aw::PointerGreater and aw::PointerLess. They are equivalent to std::greater and std::less, but they dereference each element being compared. This was necessary because the aw::Renderable class was polymorphic and referenced via pointer only, which meant the usual comparisons would have actually compared their addresses, not their values.

The main technical struggle, however, was in the complexity of my ambitious rendering engine. I decided it to render a scene which contains polymorphic layer objects, each of which can contain a polymorphic aw::Renderer and a bunch of objects that contain aw::Renderables, getting passed as pointers back to the aw::Renderer when the layer is rendered. With this system, I could have a base that is a tile map, representing the game world (which I also intended to allow multiple layers with different parallax values to make it a 2.5D engine if I wanted), and then a sprite layer on top of that into which the player and other entities would be placed, and then a UI layer on top of that which uses a rendering pattern similar to HTML5 DOM.

I spent a lot of time on this rendering code, and I am glad to say that I made quite a bit of progress in the process, but it also means that I didn’t have enough time as the idea that I had would have required. I was able to get the preloading and menu completed, but not much beyond that. I actually ended up trying to temporarily bail on the new rendering engine and write raw rendering code within the last 12 hours of the jam as a last-ditch effort to get a workable game by the deadline, but by that point I had not slept in a long while and I didn’t have the focus to keep myself awake.

At some point, I decided that this jam and its very undesirable theme was not worth the suffering. I remember waking up with my face down on my laptop, completely disoriented, with the morning sun shining brightly on me, and at that point I decided to close the project on the ldjam website and go to sleep. I woke up at about 11PM that evening. So much for my sleep schedule.

Future Plans

I was quite disappointed in the theme for this Ludum Dare, and I can’t help but wonder if the reason we’ve started getting worse and worse themes over the last few years might be directly correlating to the improvements being made to the ldjam website and making voting easier. They received well in excess of three thousand votes for the theme, but based on past trends, I think we can expect approximately a third of those people to submit games. Thus, it seems likely that many of the people voting on the theme have little to no intention of making a game for it, and therefore they have no interest in making sure the theme is workable, reasonable, and doesn’t cut out new developers.

My suggestion of improvement would be to allow theme voting only for users with submitted, completed, and rated jam or compo submissions to vote. In my opinion this would drastically improve the themes. That said, I don’t think that is likely to happen. Given that, next Ludum Dare, I may or may not participate depending on the theme. If the trend of worsening themes continues, I will not be participating in Ludum Dare 42. Nonetheless, I do intend to do a game jam in August. That is not a question, what is a question is whether or not I will be following the chosen theme or the standard deadline. I’ve been toying with the idea of running my own week-long jam with a theme chosen by either myself or by taking one of the losing themes from a previous Ludum Dare. Obviously I’d lose out on some of the community features of Ludum Dare, but it would still provide more or less the same training effect, and I think in the course of a full week, I’d be able to create a more-than-trivial game design.

Game Development Game Jams Software Development

Ludum Dare 38-40 Postmortem

It’s been nearly a year since I participated in Ludum Dare 38, which was my first ever game jam. I finished the game, and received decent ratings (I mean, not great over all, but given it was my first one), placing me between the 500th and 700th place in the rankings. I also participated in Ludum Dare 39, which unfortunately never made it to the playable stage by the 72 hour deadline. Ludum Dare 40 I likewise did not finish, however it was much more finished than 39, and was more technically advanced than either of the previous attempts.

Ludum Dare 41 is coming up in less than a month, and as I try to prepare my game engine implementations, now seems like as good a time as any to do a postmortem on each of my experiences.

Ludum Dare 38 – Asteroid Field

Let’s start with a simple explanation of my concept for Ludum Dare 38. The theme was “A Small World.” My game was called “Asteroid Field,” and was a game wherein you play as the planet earth, firing missiles into space to blow up large asteroids that are careening randomly toward your tiny planet. As time progresses, so does the average size, number, and speed of asteroids. The more points you score, the better your missiles get.

It was written in JavaScript using ES6 and transpiled and bundled with Webpack and Babel. The game engine was Phaser CE 2.

The majority of my time was spent learning the Phaser engine, which I had never used before. I had especially debilitating delays caused by issues with collision physics and particle emitters as implemented in Phaser then. I ended up implementing the physics collision math myself instead of going through the game engine, as the built-in arcade physics that I had initially intended to use gave strange behavior, as everything was expected to be a square, whereas my assets were generally better represented as circles. Unfortunately, my reliance on circles for hitboxes resulted in performance-killing trigonometry in the inner loop, which makes it difficult to play on older computers. I also made the mistake of starting the project without using the pushdown game state system, which resulted in having to significantly refactor my code when I decided I needed a game over screen.

My next biggest use of time was late-phase debugging, which I think is largely due to the fact that I went into this challenge knowing very little about the library I was using. I spent very little time on creating assets, game design, and play testing/balancing.

Overall, I would say I did a great job of limiting the scope of the project to make it realistic for my experience level with the tools, format, and process. Right from the start, my strategy was to create a game design with minimum complexity of mechanics, but with a lot of potential for cosmetic and very simple gameplay additions that could improve on the barebones concept. This strategy worked well for a first game.

Aside from inexperience, which can only be remedied over time, I think the primary lesson that I learned from this experience was that I needed to plan things more effectively. I think more complete mockups of the design, as well as figuring out the requirements for things like the physics engine going into the project would have helped me to avoid many roadblocks.

Ludum Dare 39 – Blackout (Incomplete, Unplayable)

A few months after Asteroid Field, I participated in Ludum Dare 39, for which the theme was “Running Out of Power.” My game was called “Blackout”, and the premise was that you would play as a dispatcher for a power company, and your screen would be a control panel showing a city and providing notices when the city’s power grid was damaged. Your job would be to dispatch your repair crews as effectively as possible to keep the power on for the greatest number of people. If you were not powering part of the city, that part would not be paying you, and if enough people are without power, the power company loses money. You lose when your company runs out of money.

This game was built on the same tech stack as Asteroid Field.

During this project, I spent the majority of my time, disappointingly, designing the digital representation of a city. This project was a lot more ambitious than my last one. From the design perspective, it didn’t seem that much more complex, certainly not enough to prevent me from completing the game on time. What I underestimated, however, was the complexity of the “street node” system, and the difficulty of implementing both the rendering and the physics of the vehicles travelling along said street nodes. I did get so far as determining that there needed to be object representations of “intersections” and “roads.” Intersections would contain references to each road that connected to them, and each road would contain references to each intersection acting as an endpoint. Additionally, roads would contain data on the amount of traffic, the speed of the road, and sometimes control points, through which a Catmull-Rom spline would travel to create curved or windy roads. The vehicles would be dispatched by passing their origin, destination, and the city grid to an A* pathfinding function, which would spit out the turn-by-turn directions. An update loop callback would then be responsible for moving the vehicle along this path based on the speed and traffic values for the street upon which the vehicle is currently traveling.

That design was straightforward enough. Unfortunately, that is more or less the entirety of the implementation that I had even figured out, let alone implemented. A number of problems appeared this time around. First of all, how do I draw this city? Well what I did was literally to draw it on a sheet of paper, and then draw a grid on top of it and manually write out a big long JavaScript object containing the intersections and streets and their coordinates as they appeared on the sheet of paper that I drew up. This took an ENORMOUS amount of time. I spent over a day and a half doing just this. With this task figured out, I also needed to implement the preloading system and game menu. Fortunately, I was able to complete those things, and I do have a menu complete with the ability to name your power company. After that, I needed to render the city. I had initially determined that a Catmull-Rom spline would be the best way to implement curves in the roads, since I could simply give it coordinates that fell on the path instead of off-path control points which Bezier curves need. Unfortunately, after completing the map, I found that the game engine I was using had already implemented Bezier curves, but not Catmull-Rom, which were more complex. At this point, I realized that I needed to implement the curve algorithms myself. This was about where I was when 72 hours came to an end. The extent of playability is that you can load the game, name your company, and start the disappointingly blank screen that is the “playing” state, even though somewhere in your browser’s memory is an invisible and very complex street map that I painstakingly wrote out by hand.

I think that the biggest lesson here, is, once again, to learn how to better plan ahead of time, better consider the technical limitations of the game engine at the time of the contest, and to better assess the difficulty and depth of the gameplay elements. I think this might have also gone better if I had been able to adapt the design as issues appeared, which might have been possible if I had more often benchmarked my progress according to a schedule.

Ludum Dare 40 – Speed Fishing (Incomplete, Kind Of Playable, Pretty Neat)

Okay, Ludum Dare 40 was the best of times, and the worst of times for me. I had hyped myself up for this challenge, for which the theme was “The More You Have, The Worse It Is.” I’m not going to lie, I hated the theme for this one. But that’s how Ludum Dare goes sometimes, and that’s what’s so cool about it. You show your adaptability by taking the theme and working with it, regardless of your feelings towards it. And so I did.

My game was called “Speed Fishing,” and its premise was that you are a fisherman in a fishing boat. You must collect as many fish as you can in a specific time limit. Before the timer is up, you must return to the starting place. You drive your motorized boat out into the water, avoiding obstacles such as land, sharks, and battleships, and collect the fish as you go. The more fish your boat contains, the more difficult it is to accelerate, brake, and turn, thus making travel more perilous.

This time, I broke from the web stack and decided to implement this game in C++ using SFML. I had already been working on the engine for a Minecraft-like game called Territory, and I ported much of the code from that, refactoring it to use SFML instead of GLFW. I chose SFML over GLFW because of its relative simplicity for 2D games, whereas GLFW was chosen for Territory because of its more do-it-yourself nature, and its support for Vulkan.

I spent a good part of my time working on real game features, believe it or not. That said, a few things took longer than expected because I had come from the web stack and expected functionality to be present that simply wasn’t, even in as high-level a framework as SFML. Namely, I had to figure out how to place elements on the screen correctly using direct coordinates (which I did in the previous games, but there seemed to be more helper functions available there to do things like center an asset), and I had to handle click events myself to determine if clickable elements had in fact been clicked. This click event handling was the biggest shock of all to me, although I was able to figure it out, and fortunately determining if a click lands inside a rectangle is fairly straightforward math. I also expected SFML to implement game states and associated functionality, but that was also left to me. Fortunately, I had already done most of that in the Territory project. As in the last Ludum Dare, however, the complexity of the game map implementation was one of the biggest consumers of time. In this case, I wanted the world to be mostly ocean with some land, and I wanted everything to be generated procedurally using perlin noise. I also needed to guarantee that the boat would spawn in water. Additionally, I needed to use the flyweight pattern for the rendering of the map itself, as I didn’t want to have millions of instances of multi-byte objects eating up large swaths of fragmented memory and slowing down the rendering because of CPU prefetch misses. I also needed to be able to move the player entity around through the world, all while keeping the camera centered on it. Because the world was larger than the screen, I also didn’t want to have to render the tiles that were outside of the visible screen area.

All of these features, I was able to implement, and just in time for the deadline no less. Unfortunately, things like the menu, score-keeping, fish entities, enemy entities, land collision, timer, and boat movement physics did not get completed within the time limit.

This time around, I will say that I had more distractions than before, and therefore I could have put more focus into this project than I did. Despite that, however, this project has more lines of hand-written code than both previous projects, and despite being incomplete, it is more technically complex than the completed Asteroid Field game, and I am truly proud of it. In all 3 Ludum Dare experiences, this one is the one of which I am the most proud. So that’s the good. The bad, however, is that the last day is one of which I did not sleep one minute. In fact, when the 72-hour mark was met, I had been awake for 30-something hours. I felt awful and tired. There were many moments between the 24-hour mark and the end that I was absolutely suffering. But I was determined to finish something, to be proud of something. I succeeded at that, and I am grateful.

I think one of the things that I learned with Speed Fishing was that I loved C++ more than I loved JavaScript. I also learned that code reuse is a beautiful and helpful thing, and I need to be doing more of that. This project, Speed Fishing, is the origin of a game engine I created called “ArcticWolf,” which comes after “TimberWolf,” which is the one that I used in Territory. Each of them is a specialization of a very deliberately similar API. I will be able to use these engines in not only future Ludum Dare projects, but also in free and commercial games that I will be releasing via my game company “Danger Zone Games.” So in a way, Ludum Dare 40 was the beginning of Danger Zone Games, it was the beginning of me making modular and reusable game engines, and created the ArcticWolf game engine (which was originally borrowed code from TimberWolf, which was borrowed code from Territory).

The Future!

I am very excited to participate in future Ludum Dare jams, and I am very excited to be creating games at long last. It’s been a dream of mine for a very long time, and it’s been a wild ride getting to where I am now. Even though I’m not making money on my games yet, I still love it. For me, game development isn’t a job or an industry. Game development is an amazing art. It incorporates technical skill through programming, graphic art and musical talent through game assets, and psychology through gameplay design. When you’re on your own, you have to be a skilled artist and technician in each of these fields. When you work with others, you may only need to specialize in one, but as a team your talents must stay in sync. I am proud to be a part of this community, and I am excited to see what we can all achieve in the coming years.