[Renderers/SDL3] Adds an example using SDL3 as a renderer

[LiquidityC]

This example is rather basic but it does provide an example how one could setup a rendering loop between clay and SDL3.

Although SDL3 is in its infancy and doesn't have an official stable release the API has been locked so there shouldn't be any code adaptations required for this example if one was to update to a more recent SDL3 release in the future.

[nicbarker]

Awesome, thank you for the contribution! I will take a proper look at this over the next week or so 👍

[SiebrenW]

Small remark here, which was already present in the other examples: you're replacing the flags here instead of adding them. Ideally, you'd write something like

set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -g -Wall -Werror")

[LiquidityC]

Done

[SiebrenW]

You probably want to use <lowercaseName>_SOURCE_DIR instead of _debs/sdl-src https://cmake.org/cmake/help/latest/module/FetchContent.html

So that'd be:

set_property(DIRECTORY "${sdl_SOURCE_DIR}" PROPERTY EXCLUDE_FROM_ALL TRUE)

[LiquidityC]

I did not know that this variable existed. Thanks. I'll need to revisit some of my projects now I think 😄

[kattkieru]

This tag failed for me when I tried to build your PR. I recommend changing the GIT_TAG to main until a proper SDL_ttf version is tagged and released for SDL3.

[LiquidityC]

I'll swap it to main for now. Once there's an official stable SDL3 release i assume there'll be a related tag set in SDL_ttf. I think the risk of breakage should be rather low at this point even if we do point out main.

[kattkieru]

Tested as working on macOS 15.2 -- thanks for this! I appreciate that you took the time to wrap in SDL_ttf. I also like that you used the new callbacks method for integration. I'm all-in on SDL3 so it's nice to see others adopting it for new, useful frameworks like Clay.

I left one comment on the SDL_ttf version, above. Otherwise, the demo works a treat.

My thoughts:

• Do you think it would be good to split this into a renderer that could be shared?
• Should this be using dynamic libraries by default?

I'd also love to see the demo essentially replicate the Raylib scroller, which would involve adding SDL_image to the build. (I'm one of those weirdos who thinks SDL_image and SDL_ttf should be part of the base library, though. 🤣 )

[LiquidityC]

Tested as working on macOS 15.2 -- thanks for this! I appreciate that you took the time to wrap in SDL_ttf. I also like that you used the new callbacks method for integration. I'm all-in on SDL3 so it's nice to see others adopting it for new, useful frameworks like Clay.

I left one comment on the SDL_ttf version, above. Otherwise, the demo works a treat.

My thoughts:

• Do you think it would be good to split this into a renderer that could be shared?
• Should this be using dynamic libraries by default?

I'd also love to see the demo essentially replicate the Raylib scroller, which would involve adding SDL_image to the build. (I'm one of those weirdos who thinks SDL_image and SDL_ttf should be part of the base library, though. 🤣 )

Nice that it worked.

Regarding extensions. There is one caveat with the builtin renderer in SDL. There's no ability to render circles out of the box. I didn't look into the "border" rendering commands from clay. But my best guess is that there might be some issues with this and the border radius. This will require bespoke solutions per project that does chose to utilize clay.

For me that's a reason to avoid providing a default SDL renderer within clay and instead leave that to the user to solve for their particular case.

Granted I'm not the maintainer of the repo and if there's an interest in extending this renderer to a provided solution I'm open to help out.

[kattkieru]

There is one caveat with the builtin renderer in SDL. There's no ability to render circles out of the box.

Yes, it's been a weird API hole for decades. That said, you could render circles using SDL_RenderGeometry (providing "circles" in the form of triangles). I know that SDL_RenderPoint has too much overhead for a circle rasterizer, but I haven't tested SDL_RenderPoints, which allows for passing a bunch of points at once-- perhaps the latter would be the easiest path? I might run a test.

[kattkieru]

Another recommendation: I'd switch SDL3's tag to main as well. They added live window resizing to macOS but it's only within the past week. When 3.2.0 hits I could see pinning to that version.