Struct ScanoutTarget 

#[non_exhaustive]
pub struct ScanoutTarget {
    pub connector_id: u32,
    pub crtc: CrtcChoice,
    pub primary_plane_id: u32,
    pub mode: Mode,
    pub primary_formats: FormatTable,
}

Somewhere to scan out.

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

connector_id: u32

The connector with a display on it.

crtc: CrtcChoice

The CRTC that will drive it.

primary_plane_id: u32

That CRTC’s primary plane.

mode: Mode

The mode to set.

primary_formats: FormatTable

What the primary plane will scan out.

Synthesized as LINEAR-only when the driver exposes no IN_FORMATS, so this is never empty on a plane that works – see PlaneRegistry::from_capabilities.

Implementations

impl ScanoutTarget

pub fn discover(device: &Device) -> Result<Result<Self, ScanoutError>>

Find an output with a display on it, preferring connector types in rank::MAIN order.

Enables universal planes, without which the kernel hides primary and cursor planes and this could only ever fail. Most callers will have set it already without meaning to: measured on amdgpu, a client with neither capability sees 2 planes and one that has gone atomic sees all 10, because the kernel turns universal planes on with atomic. It is asked for here anyway, so a caller that has not gone atomic yet gets an answer rather than a confusing NoPrimaryPlane.

Errors

ScanoutError for each way there is nothing to drive, or CoreError if the device cannot be read.

pub fn discover_ranked( device: &Device, ranks: &[Interface], ) -> Result<Result<Self, ScanoutError>>

As ScanoutTarget::discover, preferring displays in ranks order.

The rank is a preference, not a filter. When nothing connected matches it, the first eligible connector is used anyway – it is a display, and refusing to drive it leaves a machine looking headless with a picture on it. So rank::INTERNAL on a machine with only external outputs still returns one of them.

A caller that wants the strict reading – an instrument cluster that must show nothing rather than appear on the docking monitor – ranks the connectors itself with rank_pick, which returns None when none match.

Errors

As ScanoutTarget::discover.

pub fn discover_connector( device: &Device, connector_id: u32, ) -> Result<Result<Self, ScanoutError>>

As ScanoutTarget::discover, for one connector; 0 is ScanoutTarget::discover itself.

For shared-display controllers, which publish one connected connector per display consumer and light only the one actually presenting: the first connected connector can be an unlit output that reports perfect flips (drm-cxx 882dbf8). Never falls back to another output.

Errors

As ScanoutTarget::discover, with ScanoutError::ConnectorUnavailable when that connector is not connected or has no mode.

Trait Implementations

impl Clone for ScanoutTarget

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ScanoutTarget

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

Formats the value using the given formatter.