Struct zaplib::Shader

pub struct Shader {
    pub build_geom: Option<fn() -> Geometry>,
    pub code_to_concatenate: &'static [CodeFragment],
    pub shader_id: AtomicUsize,
}

Contains all information necessary to build a shader. Define a new shader.

Pass in a Geometry which gets used for instancing (e.g. a quad or a cube).

The different CodeFragments are appended together (but preserving their filename/line/column information for error messages). They are split out into base_code_fragments and main_code_fragment purely for convenience. (We could instead have used a single slice but they are annoying to get through concatenation..)

TODO(JP): Would be good to instead compile shaders beforehand, ie. during compile time. Should look into that at some point.

Fields

build_geom: Option<fn() -> Geometry>

The Geometry that we will draw with, if any. Can be overridden using [DrawCallProps::gpu_geometry].

code_to_concatenate: &'static [CodeFragment]

A bunch of CodeFragments that will get concatenated.

shader_id: AtomicUsize

The id of the shader (index into Cx::shaders), or Shader::UNCOMPILED_SHADER_ID if uninitialized. You should never read or modify this manually (see TODO below).

TODO(JP): This shouldn’t be public, but right now that’s necessary for using Shader::DEFAULT. We might want to switch to a define_shader helper function once we can pass function pointers to const functions (see https://github.com/rust-lang/rust/issues/63997 and https://github.com/rust-lang/rust/issues/57563).

Implementations

impl Shader

pub const DEFAULT: Shader

TODO(JP): We might want to switch to a define_shader helper function once we can pass function pointers to const functions (see https://github.com/rust-lang/rust/issues/63997 and https://github.com/rust-lang/rust/issues/57563).

We suppress clippy::declare_interior_mutable_const here since we don’t actually want shader_id in this constant to be editable.

pub fn update(
    &'static self,
    cx: &mut Cx,
    new_code_to_concatenate: &[CodeFragment]
) -> Result<(), ParseError>