[WIP] Include renderer inside the library instead of explicitly providing them at project level

[Logickin-Lambda]

As suggested previously, I was thinking of putting the renderer backend inside the library so that users can use the library out of the box by selecting a preferred backend along with the related dependency instead of providing the renderer from their ends.

So far, I have gotten a working solution, and all you need is to choose a renderer at build.zig in your projects as shown:

const raylib_dep = b.dependency("raylib_zig", .{
	.target = target,
	.optimize = optimize,
});
root_module.addImport("raylib", raylib_dep.module("raylib"));
root_module.linkLibrary(raylib_dep.artifact("raylib"));

const zclay_dep = b.dependency("zclay", .{
	.target = target,
	.optimize = optimize,
	.renderer = .raylib,
});

// if you use custom renderer from your projects, skip the addImport function
zclay_dep.module("zclay").addImport("raylib", raylib_dep.module("raylib"));
root_module.addImport("zclay", zclay_dep.module("zclay"));

At the application level, instead of loading your renderer file, all you need is to fetch the renderer from the zclay module as shown:

const cl = @import("zclay");
const renderer = cl.renderer;

This works because under the hood, the library picks and selectively compile the renderer based on the switch statement, controlled by the .renderer option:

pub const renderer = switch (@import("zclay_options").renderer) {
    .custom => .{},
    .raylib => @import("renderers/raylib_render_clay.zig"),
};

Where the @import("zclay_options").renderer is an enum defined in the build.zig of the library:

const Renderer = enum {
    custom,
    raylib,
};

As you can see, with this implementation, for every new backend added into the library, the contributors can simply add a new name into the enum and loading their renderer at root.zig by expending the switch statement with their imports.

To test the upgrade, you may build the example raylib-sidebar-container from my fork to see how the new option behaves and to verify the result. I didn't update raylib-clay-official-website because I want to show you that the original method still works so that it offers a way for users to test and build their own renderer.

I am a bit tired now, so my speaking is a bit incoherent. Please let me know if you have any questions.