Struct WgpuBackend 

pub struct WgpuBackend { /* private fields */ }

Headless GPU backend implementing RenderBackend.

Implementations

impl WgpuBackend

pub fn headless(width: u32, height: u32) -> Result<Self, UiError>

Initialise a headless backend with an offscreen target of width × height physical pixels.

Errors

Returns UiError::Unsupported when no GPU adapter is available (so the caller can skip on a machine without a usable GPU), or UiError::Backend when device creation fails.

pub fn set_clear_color(&mut self, color: Color)

Set the colour the offscreen target is cleared to before each frame.

pub fn clear_color(&self) -> Color

Return the current clear colour.

pub fn width(&self) -> u32

Target width in physical pixels.

pub fn height(&self) -> u32

Target height in physical pixels.

pub fn readback_rgba(&self) -> Result<Vec<u8>, UiError>

Read the offscreen colour target back into a tightly packed width * height * 4 RGBA byte vector (row padding stripped).

Errors

Returns UiError::Render if the GPU poll or buffer mapping fails.

pub fn read_pixel( &self, x: u32, y: u32, ) -> Result<Option<(u8, u8, u8, u8)>, UiError>

Read back a single pixel as (r, g, b, a), or None if out of bounds.

Trait Implementations

impl RenderBackend for WgpuBackend

fn surface_size(&self) -> Size

Return the target surface dimensions in physical pixels.

fn supports_gradients(&self) -> bool

Return true if this backend can render gradient fills.

fn supports_paths(&self) -> bool

Return true if this backend can render arbitrary vector paths.

fn execute(&mut self, list: &DrawList) -> Result<(), UiError>

Replay an entire DrawList onto the backend’s surface.

fn supports_blur(&self) -> bool

Return true if this backend can render blur effects (e.g. box shadows).

fn supports_images(&self) -> bool

Return true if this backend can blit ImageData.

fn supports_text(&self) -> bool

Return true if this backend can render text via DrawCommand::DrawText.