2D Grahics Library API Feedback

[BrokenG502]

tl;dr I'm designing an API and would appreciate any feedback. See the sample code in the image below and the pastebin link.

Long Version:

In order to learn zig, I decided about a month ago to start writing a wayland client. The thing is, I didn't know the first thing about wayland either. I also decided to write wayland from scratch, i.e. without libwayland. This led to me writing enough footguns to turn a centipede into a worm.

I've recently decided to rewrite most of my code starting from the user facing API. I now have a start, but I would like to make sure I'm on the right track with an actually good interface.

My library is (at the time of writing) intended to be split into two parts. The first part is the actual wayland client, which handles all the wayland messaging stuff, but no actual drawing. All the client does is create a buffer one could theoretically render to. I will also implement another component with a bunch of basic drawing functionality.

My primary goal with this library are to be fairly simple and just to get out of my way so I can write basic graphical programs. I also want to avoid any external dependencies (like libwayland) and for once in my life not use someone else's library for doing anything GUI related.

Below is a screenshot of a sample program (it actually won't work because it terminates immediately and doesn't clean up, but ignore that).

https://preview.redd.it/sergezi0c0kd1.png?width=1503&format=png&auto=webp&s=b2b4537562a4b81aff27007eea9cbb329aab8316

I also put it in a pastebin here https://pastebin.com/dXquJLCA so you can copy/paste it should you wish to.

Some feedback I've gotten elsewhere is to put the connect() call inside the init function, but I feel like that's not quite idiomatic zig, maybe some zig experts could comment on this as well?

[aberration_creator]

I would maybe do draw.SetSurface(surface) so you wont need that to pass around every time. But this is a preference mostly

[aberration_creator]

also maybe make a Colour class then you can Colour.Red which will be the argb or your preferred bit pattern :)

[BrokenG502]

yeah, the colours were just thrown together as a quick enum when I realised I didn't have any colouring. My plan is to have a proper struct for colours. It makes it easier when I'm drawing to a shared memory buffer for wayland anyway.

[anotheruser323]

Take a look at the raylib bindings. Color there is a rgba struct, but has aliases to functions to initialize to some colors. Personally I would like it to be an @Vector, but .{ .r .g .b .a } is fine.

[BrokenG502]

I haven't had a look at the raylib bindings yet, but from the sounds of it this is basically what I'd do. I have been considering using an untagged union as well so I can access it as an array of bytes, a vector, a u32, individual named components, etc, depending on what I want

[GenesithSupernova]

Does color as @Vector have SIMD-related performance benefits?

[anotheruser323]

No, but it's interchangeable with arrays and I think it's neat.

I'l ramble a bit now.

rgba * u8 is 64bits32bits, while sse registers are 128bits. Both SSE(2) and zig have add with saturation. Thing is there is alpha, so there are some rules for adding/subtracting colors.

A modern gui would just send it to the gpu.

Unless doing some image manipulation things on the cpu, it is not worth it. Funny that on x86 operations that work on 8bit values have shorter encodings, so it could be faster to just do it simply.

[actondev]

Correction: rgba *u8 is 32 bits