246 votes
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Why is it so bad to optimize too early?

Preamble: A few objections have been raised in the comments, and I think they largely stem from a misunderstanding of what we mean when we say "premature optimization" - so I wanted to add a little ...
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  • 115k
54 votes
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How are entity systems cache-efficient?

The two key benefits that I constantly hear lauded about entity systems are 1) the easy construction of new kinds of entities due to not having to tangle with complex inheritance hierarchies, and 2) ...
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54 votes
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Optimization of rendering of cube world

No high-performance voxel renderer draws individual cubes or cube faces. To get good performance, groups of voxels are assembled together into a single mesh, called a "Chunk". A chunk is typically ...
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  • 115k
44 votes

Why is it so bad to optimize too early?

note: this answer began as a comment on DMGregory's answer, and so doesn't duplicate the very good points he makes. "Would it not be incredibly difficult to change some of the core structures of the ...
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  • 814
44 votes

Is the Microsoft recommendation to use C# properties applicable to game development?

But my impression is that in game development, unless you have a reason to do otherwise, everything should be nearly as fast as possible. Not necessarily. Just like in application software, there is ...
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  • 112k
28 votes
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Which opcodes are faster at the CPU level?

Agner Fog's optimization guides are excellent. He has guides, tables of instruction timings, and docs on the microarchitecture of all recent x86 CPU designs (going back as far as Intel Pentium). See ...
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26 votes

How can I shorten the length of time spent on finding a path using my A* pathfinding code?

Let's start with some general C# optimization advice: Avoid heap allocations in your hot path. That means anywhere you have new Foo(...) where ...
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  • 115k
25 votes

Why is it so bad to optimize too early?

"Do not optimise early" doesn't mean "pick the worst possible way to do things". You still need to consider performance implications (unless you're just prototyping). The point is not to cripple other,...
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  • 845
23 votes
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How do Minecraft know where village's buildings are if the village is not generated yet?

Yes, it generates more chunks (or at least more of the village tree) than you think it does. This is what I call "area of interest" in my voxel code. There are two kinds of area of interest: Logical (...
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18 votes
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How to reduce the time taken to path-find to an unreachable location?

Using a bidirectional path finder usually solves this issue if the area the player is stuck in is small. They basically advance from the player's position and the destination at the same time and when ...
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  • 14.5k
13 votes

How to load a spherical planet and its regions?

As you've already shown, there are a number of solutions to this problem, but none 100% ideal. Spheres are tricky. Cube-based One common route, used by Spore and quite likely other games (though it'...
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  • 115k
13 votes

How can City-sim simulate hundreds of characters?

Like so much of gamedev, the answer to how city sim games accomplish this seemingly-impossible feat is: they probably don't. They're just faking it well. ;) Sims like these will typically operate on a ...
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  • 115k
13 votes

How to reduce the time taken to path-find to an unreachable location?

You should make a sort of connectivity map - by flood-filling all unconnected walkable areas and marking each one with a different tag, once at game start (and every time when terrain changes). Then, ...
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  • 10.1k
11 votes
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In a 2D physics engine, how do I avoid useless collision resolutions when objects come to a rest?

I suspected OP already knew this approach so I mentioned it in a comment as just a starting point, but I'll try fleshing it out a bit more... Most physics engines divide dynamic objects into two ...
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  • 115k
10 votes
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How to make illusion of round world?

You can do this purely in a vertex shader. You'd want to apply this shader to everything you render. One trick though that you can do is weight it so that the nearby objects are flat out to say 100 ...
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  • 584
10 votes

Why is it so bad to optimize too early?

A lot of the answers seem to be focusing a lot on the performance aspect of "optimization" while I myself like to look at optimization and the whole ordeal of optimizing too early at a more abstract ...
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10 votes

Is the Microsoft recommendation to use C# properties applicable to game development?

When in doubt, use best practices. You are in doubt. That was the easy answer. Reality is more complex, of course. First, there's the myth that game programming is ultra super high performance ...
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  • 9,937
9 votes

Games able to use 4+ core CPUs properly

Games will not benefit that much by having 4 cores instead of two. Here's why. Basic Game Engine: 1 Thread The problem with graphics API like DirectX and OpenGL is that it must be runned on one ...
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9 votes

For Vertex Buffer Steaming, Multiple glBufferSubData VS Orphaning?

This is a complex question with a lot of small details that really matter, the performance will vary based on platform and application. So you should profile for possible bottlenecks before investing ...
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  • 12.5k
9 votes

How to optimize collisions

Query only nearby objects As you already know, you need to check only nearby objects. This means that you need a way to retrieve a list of nearby objects to check. To do that, you need to divide the ...
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  • 18.9k
9 votes

How do Minecraft know where village's buildings are if the village is not generated yet?

Technical stuff During Minecraft's chunk generation a chunk passes several stages before it is done and can be rendered. These stages, in order, are as follows: ...
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  • 201
8 votes
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Component-wise GLSL vector branching

You can optimize this to be branchless actually, however for seeing if it's faster you always want to profile it: ...
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  • 3,203
8 votes

Store values or calculate values

The real implications in performance here depend 100% on the platform used. Say you have written code as in option 2. When using a statically compiled language such as C++ the compiler will ...
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  • 10.2k
8 votes

How do I efficiently check if a point is inside a rotated rectangle?

Edit: The OPs comment has been skeptical about the efficiency of the suggested negative circular bound check to improve the algorithm in order do checks whether an arbitrary 2D point lies within a ...
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  • 823
8 votes
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Possible to yield a coroutine when it is taking too long to run?

You can use Time.realtimeSinceStartup as reference for the time passed: ...
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  • 1,515
8 votes

Why is it so bad to optimize too early?

Money. It comes down to that. Money. Since time is money*, the more time you spend on activities that are not guaranteed to generate more money (i.e. you can't consider these activities as ...
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  • 15.7k
7 votes
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C++ Object management/deletion

You're using a std::vector<Bullet>. This has the advantage of keeping data contiguous in memory, so iterating over it is fast (it has something to do with ...
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  • 15.7k
7 votes

Is there a difference between using one large mesh with 100k polygons and using 1000 meshes with 100 polygons each?

There are two main components to the time it takes to process a draw call: The time it takes to calculate all the results for every work item in the batch The time it takes to upload info / switch ...
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  • 115k
6 votes
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How to PRECISELY measure execution time of a code?

For the kind of micro-optimisation that you are trying to do, nothing will beat real-life usage patterns, with your algorithm embedded in a real program, consuming and producing real data. There are ...
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  • 14.6k
6 votes
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Efficiently Handling Entity-Interactions in a Tile-Based World

You have 3 major options: 1: Implement some kind of sorting or data structure. For example: Keep monsters in a list/array (Something you are probably already doing) and sort them by ...
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