Defold engine code overview

https://defold.com/2020/12/27/engine-overview-pt1/

by ingve • 6 years ago

78 45 6 years ago

I haven't seen Defold before, but the message-passing architecture looks very interesting, so thanks for bringing it to my attention.

I have a couple of random questions, in case someone who knows the answers sees this:

1. Why protobuf and not Cap'n'Proto or Flatbuffers? Last I checked, both were better at zero-copy decoding, which might be a big deal for an engine with a message-passing architecture. Cap'n'Proto has had a lot of improvements for RPC use over the past few years.

2. Why HTTP/S rather than UDP? Both in terms of throughput and latency, UDP tends to come out ahead. Was it just not an issue?

3. Why WebP for compressed textures rather than KTX2, which offers BasisU supercompression? Doing so can get similar compression and greatly improve performance when decoding to GPU formats.

4. Any plans to support GLTF2? It has potential to replace custom engine formats, at least those that don't store data for easier GPU consumption, especially if used with meshopt. Unless the Defold format stores data in a GPU-ready format, it might be a good future option, and doing so would simplify asset pipelines a bit.

nacs• 6 years ago

Why HTTP/S sockets rather than raw UDP

Because Defold targets mobile mostly and https/websockets does better at working with corporate firewalls and VPNs.

Also mobile games typically aren't as latency-sensitive as real-time desktop games since they often have to work over slow/unreliable wireless cell networks.

britzl15• 6 years ago

Hi! Defold Foundation member here.

1. The first lines of Defold code were written more than 10 years ago and at that time Cap'n'Proto and Flatbuffers didn't exist. One could argue that we should change to a newer format, but for our purposes protobuf still works really well.

2. Defold uses LuaSockets to make TCP and UDP sockets available to developers through our Lua API. And we also make TCP sockets available to our C extension system.

3. The next big task which we will start the new year with is a full review of our texture compression formats. Basis Universal is on our list of formats to investigate.

4. While we do support import of basic 3D models our focus has been mainly on 2D content. We are currently negotiating funding for improved 3D support in a work package for 2021. If all goes well you can expect some major improvements in this area.

Feel free to ask more questions!

chris_st2• 6 years ago

Anyone give a comparison between Defold and Godot [1]?

[1] https://godotengine.org

josephcsible2• 6 years ago

One point to consider: Godot is FOSS, but Defold is only visible-source.

didibus3• 6 years ago

Seems more nuanced then that. You can use Defold to make commercial games for free. You can even extend and modify Defold and use your modified version to make commercial games for free too from what I understand.

And you can also change and modify Defold and distribute your changes and modifications to others, but you can't do so commercially. That said, I think others could still use your modified Defold to make commercial games, just you can't take any money for it.

So it seems to be much more than just visible source. Basically the only thing it doesn't allow is for you to commercialize the Defold engine or some derivative engine based on it. Everything else seems allowed.

Caveat: I am not a lawyer.

jay_kyburz3• 6 years ago

Defold is a great commercial engine used to ship real games, but has its own license "derived" from Apache 2.0. You'll have to understand it before building on the engine.

Godot is a hobby engine with a standard MIT license, but with some major issues that make it unusable for any serious work. I worked with it for 3 months at the end of last year, but had to abandon the project after logging a few serious bugs in the issue tracker.

chris_st2• 6 years ago

Thanks! Can you give a bit of detail about the bugs you ran into?

britzl15• 6 years ago

The Defold license: https://defold.com/license/

The only thing you can't do is sell Defold itself (ie the engine and editor). You can commercialise your games in any way you want and you can modify the engine and editor without having to share your modifications.

keyle2• 6 years ago

Interesting, my experience is the reverse.

I shipped a 3D game with Godot on Steam this year and it's been pretty smooth sailing.

I wasn't impressed with defold, both editor and ecosystem.

andybak3• 6 years ago

I feel strongly this page: https://defold.com/showcase/

should have screenshots not artwork. All the artwork tells me is that they employ someone who can draw. I don't care about that.

jay_kyburz3• 6 years ago

Screenshots are not going to tell you anything more. You should go get the game from the app store and see them running.

andybak3• 6 years ago

Of course they are going to tell me something more. They will tell me what the actual game looks like.

britzl15• 6 years ago

Great feedback! Thanks. You should be able to click on any of the games to get to a store page or similar where you can see screenshots of each game.

andybak3• 6 years ago

That's missing the point. I first have to decide whether I want to click on one and if so which one I want to click on.

The illustrations don't help me decide. They don't even particularly encourage me to click.

I'm sure if you came to it cold you'd see what I mean. Great illustrations aren't a rare commodity on the web - people want to know what the actual game will look like.

kennethkl• 6 years ago

to each their own. i personally like direction they took. it's minimal and gives more of a teaser. like a movie poster or game box art. I'd find adding screenshots everywhere is a little too much towards a specific niche detail

rstupek• 6 years ago

The overview doesn't mention if there is support for Metal?

britzl15• 6 years ago

Yes, Defold supports Metal through MoltenVK and the Vulkan graphics backend.

fileeditview• 6 years ago

There are a few other serious options for Lua game engines/frameworks worth mentioning when Defold comes up:

- Love2D : https://love2d.org/

- Solard2D : (previously corona sdk): https://solar2d.com/

I would really like to read a good comparison between the three one day.

britzl15• 6 years ago

Perhaps ask Mike from GamesFromScratch to do a comparison video?

One thing that will differ between the engines is the number of support platforms.

But apart from that I believe there are many similarities. Most engines today have long lists of features and they are all quite powerful. But something that usually isn't immediately obvious from a feature list is how it is to work with the engine and tools day in and day out while developing games. What are the pain-points and what are the time-savers of each engine?

We list a few things Defold does really well here:

https://defold.com/why/

bjconlan• 6 years ago

As a side note and credit to the parent author I really appreciated the work you did and helper libraries you provided (it helped me learn a lot about some of the greater functionality that the defold engine provided. I also think the choices made for this engine were under appreciated at the time (and still are given its lack of notoriety) I thought Kings move to give it a much more liberal licence might have put it in a place competitively (for 2d at least) to Godot, but I guess their momentum and ambition overshadow the great work everyone who has worked on defold (and surrounding communities has done) - not to say godot isn’t an amazing accomplishment in its own right (which it is and their ide alone a testament to the quality of craftsmanship)

didibus3• 6 years ago

Defold looks pretty nice if you're looking to make more simplistic games. I wish it could target Playstation and Xbox as well though. But I heard its tools are really nice to work with.

I also like the fact that the editor is implemented in Clojure, quite a nice showcase for Clojure.

britzl15• 6 years ago

We are actively investigating additional console support (we only support Nintendo Switch) in 2021. Follow us on Twitter (https://twitter.com/defold) to not miss any annoucements!

zerr• 6 years ago

AFAIK King is moving everything to Unity, so they have dumped their proprietary engine on github.

britzl15• 6 years ago

King still has one internal engine used in most of their franchise titles (Candy Crush, Farm etc). Defold was used internally for several years, but the major adoption was seen outside of King, so it made a lot of sense to make Defold completely independent of King earlier this year.

adenozine• 6 years ago

I've always enjoyed Lua. Does anyone have any experience with Defold? I'd like to make a little puzzle game, but I don't have dozens/hundreds of hours to learn Unity or a big fancy engine. Is Defold learnable enough for someone to make a game on the weekends over the course of a few months?

dazzawazza• 6 years ago

Personally I'd look at https://love2d.org/ if the game is 2D. It's a much more manageable scale for very small teams.

keyle2• 6 years ago

I love love2d. But one thing to take notice of when comparing, is that love2d is a game engine. Defolds ships game engine and IDE.

britzl15• 6 years ago

You can get in touch with Defold users here: https://forum.defold.com/

britzl15• 6 years ago

Here's a forum thread created by a relatively new Defold user documenting part of the process from prototype to finished game: https://forum.defold.com/t/apple-spider-casual-arcade-action...

Another from a more experienced team, but new to Defold:

https://forum.defold.com/t/travel-blast-by-mpgames/66089?u=b...

"Low entry level compared to Unity. Lua is easy to learn programming language. One of our UI designers became Defold developer in a month"

Defold engine code overview

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