Any plan on 2D game support?

[Jack-Ji]

Hi @michal-z , I've being following your work closely, nice work!

A quick question, will you consider add libs for 2d games? e.g. box2d/vector graphics/spine animation etc.

I'm asking because I think most indie developers choose 2d over 3d game (at least initially), since a decent 3d game requires way more expertise and amount of work.

[michal-z]

Hi, yes I would like to support 2D gamedev. We can use this issue for feature requests/discussion.

Regarding physics, I think we could use Jolt also for 2D. I will investigate this and ask the author of the lib about perf implications.

[Jack-Ji]

Great to hear that! Here's my wishlist:

• Sprites batching support (with optional shader effect)
• Tiled editor support
• 2D Physics
• Vector graphics
• Font system
• Animation system (3d also)
• Particle system (3d also)

Might be too much, feel free to take your pick 😊😁.

[michal-z]

Regarding font system and UI - for my game, I plan to use font and UI system from dear imgui (zgui).

[Jack-Ji]

Hmm, never thought of this. I only use imgui to make tools. For a game, I might choose
a more stylish one (with some animation behavior and colorful skins). Not sure if imgui can
deliver that.

[michal-z]

I think it can with some code tweaks. I will be trying to do it for my games because I don't want to have another UI/font system. Will see how it goes.

[Pyrolistical]

I know this isn't exactly what you want, but there is now a 2D sample https://github.com/michal-z/zig-gamedev/tree/main/samples/instanced_pills_wgpu

What might be of interest to you is the sample does an object space to clip space transform with correct aspect ratio. https://github.com/michal-z/zig-gamedev/blob/main/samples/instanced_pills_wgpu/src/InstancedPillsWgpu.zig#L629

I'm only interested in 2D as well and will simply use WebGPU with z == 0.

[Pyrolistical]

I create another 2D sample showing how to organize passes into layers https://github.com/Pyrolistical/zig-gamedev/tree/layers/samples/layers_wgpu

@michal-z I didn't submit this as a PR as I don't know if it makes sense to be a sample for zig-gamedev. Essentially there is a mini half baked graphics framework in the sample itself. What do you think?

[michal-z]

@Pyrolistical Looks nice. I think we can make a sample from it and then tweak/improve and potentially make a lib from this.

[Pyrolistical]

@michal-z the font system in imgui seems pretty limited. ootb it doesn't support rotatation/translation/scale of text

[michal-z]

Do you mean our zgui wrapper or the dear imgui lib?

[Pyrolistical]

Both? Unless you've added this functionality to zgui? I don't understanding your question.

[michal-z]

Nvm, I thought you mean that this functionality is present in dear imgui but that we just don't expose it yet.

[michal-z]

We could render imgui text to a texture and then apply a transformation when drawing this texture to the back buffer (can be cumbersome, though). What do you think?

[Pyrolistical]

Yeah, that was my first thought as well, but the texture would need to be oversized in order to compensate for the rotation blur. Doable but cumbersome.

The ideal solution would transformed the text in the shader and render out pixel perfect.

Let me implement the render to texture and rotate as a sample. We'll see just how annoying that would be.

[michal-z]

Yes, trying it out is a good idea, thanks!

[michal-z]

Jolt Physics should get 2D support soon.

[Jack-Ji]

Jolt Physics should get 2D support soon.

How's things going with 2d support of zphysics? No rush, just checking...

[michal-z]

C++ version already supports 2D. Should be pretty easy to have it in zphysics. Will research and get back to you next week.

[michal-z]

Jolt supports 2D by using constraints and locking one axis. There is a 2D example in the C++ repo added in this commit:
jrouwe/JoltPhysics@4f97968

To get this functionality we need to add "constraints" to our bindings. I will start working on it on Friday I think.

[michal-z]

Actually it seems that there is a 2D branch:
https://github.com/jrouwe/JoltPhysics/tree/feature/2d_sim

[michal-z]

I'm considering creating bindings for this lib as a 2D solution for zig-gamedev: https://github.com/grimfang4/sdl-gpu

What do you think about this?

[Jack-Ji]

Frankly, with SDL3's gpu api being actively worked, I wouldn't be very interested in sdl_gpu. Keep improving zsdl is enough to my opinion.

[michal-z]

Frankly, with SDL3's gpu api being actively worked, I wouldn't be very interested in sdl_gpu. Keep improving zsdl is enough to my opinion.

Is SDL3 gpu API work done in public? I've only seen a very rough header file. My concern is that it may take years to come (making a shader language is a huge rabbit hole).

Also, I have a feeling that official SDL3 GPU API will be a lower level HW abstraction.

But yeah, I get your point. Thanks!

[michal-z]

Here is a link to SDL3 GPU API PR: libsdl-org/SDL#7067

[michal-z]

Looks like a minimal HW abstraction layer (no batching, etc.) Looks nice but I think that something like sdl_gpu will still be needed for 2D games. Thoughts?

[Jack-Ji]

If there exists a webgpu backend for sdl-gpu, then yeah, I might give it a go. Otherwise, I prefer to SDL2 instead.

[michal-z]

Note that sdl_gpu builds on top of SDL2. It basically provides batching and better sprite support to SDL2.

[Jack-Ji]

Sorry, didn't realize that. In that case, more ziggy API for sdl-gpu does sound tempting indeed.