Enum EglDisplayKind 

pub enum EglDisplayKind {
    Gbm,
    PlatformDevice,
    Default,
}

Identifies the type of EGL display used for headless OpenGL ES rendering.

The HAL creates a surfaceless GLES 3.0 context (EGL_KHR_surfaceless_context + EGL_KHR_no_config_context) and renders exclusively through FBOs backed by EGLImages imported from DMA-buf file descriptors. No window or PBuffer surface is created.

Displays are probed in priority order: PlatformDevice first (zero external dependencies), then GBM, then Default. Use probe_egl_displays to discover which are available and ImageProcessorConfig::egl_display to override the auto-detection.

Display Types

• PlatformDevice — Uses EGL_EXT_device_enumeration to query available EGL devices via eglQueryDevicesEXT, then selects the first device with eglGetPlatformDisplay(EGL_EXT_platform_device, ...). Headless and compositor-free with zero external library dependencies. Works on NVIDIA GPUs and newer Vivante drivers.

• Gbm — Opens a DRM render node (e.g. /dev/dri/renderD128) and creates a GBM (Generic Buffer Manager) device, then calls eglGetPlatformDisplay(EGL_PLATFORM_GBM_KHR, gbm_device). Requires libgbm and a DRM render node. Needed on ARM Mali (i.MX95) and older Vivante drivers that do not expose EGL_EXT_platform_device.

• Default — Calls eglGetDisplay(EGL_DEFAULT_DISPLAY), letting the EGL implementation choose the display. On Wayland systems this connects to the compositor; on X11 it connects to the X server. May block on headless systems where a compositor is expected but not running.

Variants

Gbm

PlatformDevice

Default

Trait Implementations

impl Clone for EglDisplayKind

fn clone(&self) -> EglDisplayKind

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for EglDisplayKind

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

Formats the value using the given formatter.

impl Display for EglDisplayKind

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

Formats the value using the given formatter.

impl Hash for EglDisplayKind

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for EglDisplayKind

fn eq(&self, other: &EglDisplayKind) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for EglDisplayKind

impl Eq for EglDisplayKind

impl StructuralPartialEq for EglDisplayKind