Reduce Bugs by Pruning Your Object Graph with Temporary Objects

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One of the biggest source of bugs in our apps is state: all of that persistent data we keep around in memory. When things change we need to make sure to update all of it at the right times and with the right new parts of the state that changed. Inevitably things get out of sync and our app is in “a bad state”. Today’s article discusses some ways we can prune the “graph” of objects that we create in OOP so that there’s less state to maintain. Read on for some interesting techniques that could help you prevent bugs!

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The Many Types and Dangers of Callbacks

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Callbacks are a mainstay of the real-time games and apps we build in Unity. We’re constantly writing asynchronous code for every operation from walking a character to a destination to making a web call. It’s really convenient for these functions to “call back” and report their status so we know how the operation is going. Unfortunately there are also a lot of dangers that come along with this. Today we’ll look into the surprisingly large number of ways you can “call back” in C# and some of the ways you can get burned doing so.

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Easily Track Value Changes with Observable<T>

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A lot of times we want to take some action when a value changes. If the player’s level increases I want to play a “ding” sound effect. If a player loses health points I want the screen to flash red. Today we introduce Observable<T>: an easy way to track these value changes. Read on for the source code and examples!

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Enumerables Without the Garbage: Part 7

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Today we’ll wrap up the iterator series by finishing up porting C++’s <algorithm> header. We end up with a library of functions for common LINQ-style algorithms but without any of the garbage creation that slows our games down. Read on for the source and examples!

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Easily “Compile Out” Function Calls

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Taking another break from the iterator series, this week we’ll take a look at an exciting .NET feature that can easily and cleanly remove the calls to a function throughout the whole code base. Unity uses this for Debug.Assert and you can use it for all sorts of functions, too. Wouldn’t it be nice if we could strip out all the debug functions from the production build of our game but leave them in during development? Read on to learn how!

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Enumerables Without the Garbage: Part 6

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We’re nearing the end of the series to build a no-garbage replacement for System.Linq. Today we tackle functions that work on already-sorted ranges and functions that work on ranges that are in heap order. These include common set operations like “union” and “intersection”. Read on to see how to use them and for the updated library that you can use to eliminate your garbage creation!

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Enumerables Without the Garbage: Part 5

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This week we continue with iterators to get the functionality of IEnumerable without the nasty garbage creation. This week the little iterator library gets support for sorting and binary searching. Read on for the details!

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Enumerables Without the Garbage: Part 4

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Back from a brief break, we pick up this week by finishing up the “modifying sequence operations” with some gems like RandomShuffle and go through the “partitions” category with functions like Partition and IsPartitioned. These are all solid algorithms with a lot of potential uses, so read on to see how to use them with iterators and for the source code that implements them!

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Loop Performance: Part 4

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Today’s article takes a break from the iterator series to investigate an interesting anomaly with the List.ForEach function: it’s surprisingly fast! So fast that it’s actually competitive with regular old for, foreach, and while functions. How can it be so fast when it has to call a delegate that you pass it for every single loop iteration? Read on for to find out!

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Enumerables Without the Garbage: Part 3

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Continuing the series this week we’ll delve into the iterator functions that modify the sequence. This includes handy tools like Copy, SwapRanges, and Transform. Of course this is all done without creating any garbage! Read on to see how and for the full source code.

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