Architecture Planning

I'm still a novice rustacean and open-gl-er, so I'm not going to specify everything exactly, but we can make some pretty important decisions already.

Once again, we're not making a game engine here, we're making a single specific game, so we don't need to handle things generically.

Resource Management

One issue in Swoop is that every sprite, despite being a quad, has a different mesh. It would have required a bunch of refactoring to allow them to share mesh data. It was the same for textures.

So let's have a global resources data store. Perhaps something like:

#![allow(unused)]

fn main() {
Textures {
    rock_texture: WebGlTexture,
    ship_texture: WebGlTexture,
    ...
}


struct Resources {
    textures: Textures,
    meshes: Meshes,
    shader_programs: ShaderPrograms
}
}

Why all this static-ness. Why not hashmaps? Well, we could, but then we would lose rust's ability to typecheck. An opinion that I am slowly coming to is that users gradually find ways to dodge rusts static type checks by using indices into vectors, hash maps etc.

We can probably generate this resources struct from a folder of actual resources, so we don't need to code it by hand.

Rendering

In the STL demo we did a forward rendering pipeline. For this game I'm going to do a deferred renderer. The geometry will be rendered out to a bunch of buffers. These buffers can then be combined in another shader to output the final image.

Why did I chose deferred? Well, I'd like there to be cool effects like fog, volumetric lighting, GI etc. These can all be approximated easily using data from the signed distance field of the cave, but to do so, every mesh needs to be able to sample the cave signed distance field. It's easier to do so in a single deferred pass that has all the needed data than it is to do it in each and every fragment shader.

For a basic deferred pipeline we need a geometry buffer that contains data on:

1. Surface Normals (2xfloats)
2. Surface Depth (1x float)
3. Surface Color (3x float)
4. Surface Material Properties (3x float)

We can stuff this into two 32 bit float textures as I think 16 bit floats should be fine.

That's all???

Is this all the planning I'm going to do? Eh, probably. I'm not yet sure the best way to handle entities, so hopefully this project will help clear that up.