Enum ReadbackError 

pub enum ReadbackError {
    DeviceLost,
    MapFailed(String),
    PollFailed(String),
}

Why an offscreen readback could not produce pixels.

Every variant means the same thing to a caller — no image this time — but they are kept apart because they point at different causes: a lost device is a driver / compositor event, a failed map is usually memory pressure.

Variants

DeviceLost

map_async’s callback was dropped without firing — the device was lost before the mapping completed.

MapFailed(String)

The buffer mapping itself failed.

PollFailed(String)

poll reported a failure before the mapping could be observed.

Trait Implementations

impl Debug for ReadbackError

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for ReadbackError

fn fmt(&self, __formatter: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Error for ReadbackError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.