use wgt::{Backends, PowerPreference, RequestAdapterOptions};
use crate::{Adapter, Instance, Surface};
#[cfg(wgpu_core)]
#[cfg_attr(docsrs, doc(cfg(all())))]
pub use wgc::instance::parse_backends_from_comma_list;
#[cfg(not(wgpu_core))]
pub fn parse_backends_from_comma_list(_string: &str) -> Backends {
Backends::all()
}
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,
Ok("none") => PowerPreference::None,
_ => return None,
},
)
}
#[cfg(native)]
pub fn initialize_adapter_from_env(
instance: &Instance,
compatible_surface: Option<&Surface<'_>>,
) -> Option<Adapter> {
let desired_adapter_name = std::env::var("WGPU_ADAPTER_NAME")
.as_deref()
.map(str::to_lowercase)
.ok()?;
let adapters = instance.enumerate_adapters(Backends::all());
let mut chosen_adapter = None;
for adapter in adapters {
let info = adapter.get_info();
if let Some(surface) = compatible_surface {
if !adapter.is_surface_supported(surface) {
continue;
}
}
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(not(native))]
pub fn initialize_adapter_from_env(
_instance: &Instance,
_compatible_surface: Option<&Surface<'_>>,
) -> Option<Adapter> {
None
}
pub async fn initialize_adapter_from_env_or_default(
instance: &Instance,
compatible_surface: Option<&Surface<'_>>,
) -> Option<Adapter> {
match initialize_adapter_from_env(instance, compatible_surface) {
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
}
}
}
pub fn dx12_shader_compiler_from_env() -> Option<wgt::Dx12Compiler> {
Some(
match std::env::var("WGPU_DX12_COMPILER")
.as_deref()
.map(str::to_lowercase)
.as_deref()
{
Ok("dxc") => wgt::Dx12Compiler::Dxc {
dxil_path: None,
dxc_path: None,
},
Ok("fxc") => wgt::Dx12Compiler::Fxc,
_ => return None,
},
)
}
pub fn gles_minor_version_from_env() -> Option<wgt::Gles3MinorVersion> {
Some(
match std::env::var("WGPU_GLES_MINOR_VERSION")
.as_deref()
.map(str::to_lowercase)
.as_deref()
{
Ok("automatic") => wgt::Gles3MinorVersion::Automatic,
Ok("0") => wgt::Gles3MinorVersion::Version0,
Ok("1") => wgt::Gles3MinorVersion::Version1,
Ok("2") => wgt::Gles3MinorVersion::Version2,
_ => return None,
},
)
}