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use wgt::{Backends, PowerPreference, RequestAdapterOptions};
use crate::{Adapter, Instance, Surface};
#[cfg(any(not(target_arch = "wasm32"), feature = "wgc"))]
pub use wgc::instance::parse_backends_from_comma_list;
#[cfg(all(target_arch = "wasm32", not(feature = "wgc")))]
pub fn parse_backends_from_comma_list(_string: &str) -> Backends {
Backends::BROWSER_WEBGPU
}
pub fn backend_bits_from_env() -> Option<Backends> {
std::env::var("WGPU_BACKEND")
.as_deref()
.map(str::to_lowercase)
.ok()
.as_deref()
.map(parse_backends_from_comma_list)
}
pub fn power_preference_from_env() -> Option<PowerPreference> {
Some(
match std::env::var("WGPU_POWER_PREF")
.as_deref()
.map(str::to_lowercase)
.as_deref()
{
Ok("low") => PowerPreference::LowPower,
Ok("high") => PowerPreference::HighPerformance,
_ => return None,
},
)
}
#[cfg(not(target_arch = "wasm32"))]
pub fn initialize_adapter_from_env(instance: &Instance, backend_bits: Backends) -> Option<Adapter> {
let desired_adapter_name = std::env::var("WGPU_ADAPTER_NAME")
.as_deref()
.map(str::to_lowercase)
.ok()?;
let adapters = instance.enumerate_adapters(backend_bits);
let mut chosen_adapter = None;
for adapter in adapters {
let info = adapter.get_info();
if info.name.to_lowercase().contains(&desired_adapter_name) {
chosen_adapter = Some(adapter);
break;
}
}
Some(chosen_adapter.expect("WGPU_ADAPTER_NAME set but no matching adapter found!"))
}
#[cfg(target_arch = "wasm32")]
pub fn initialize_adapter_from_env(
_instance: &Instance,
_backend_bits: Backends,
) -> Option<Adapter> {
None
}
pub async fn initialize_adapter_from_env_or_default(
instance: &Instance,
backend_bits: wgt::Backends,
compatible_surface: Option<&Surface>,
) -> Option<Adapter> {
match initialize_adapter_from_env(instance, backend_bits) {
Some(a) => Some(a),
None => {
instance
.request_adapter(&RequestAdapterOptions {
power_preference: power_preference_from_env().unwrap_or_default(),
force_fallback_adapter: false,
compatible_surface,
})
.await
}
}
}