Struct ContextData 

pub struct ContextData {
    image_key: Option<ImageKey>,
    size: DeviceIntSize,
    inactive_staging_buffers: ArrayVec<StagingBuffer, PRESENTATION_BUFFER_COUNT>,
    presentation: Option<PresentationStagingBuffer>,
    next_epoch: Epoch,
}

The embedder process-side representation of what is the GPUCanvasContext in script.

Fields

image_key: Option<ImageKey>

The ImageKey of the WebRender image associated with this context.

size: DeviceIntSize

The current size of this context.

inactive_staging_buffers: ArrayVec<StagingBuffer, PRESENTATION_BUFFER_COUNT>

Staging buffers that are not actively used.

Staging buffer here are either StagingBufferState::Unassigned or StagingBufferState::Available. They are removed from here when they are in process of being mapped or are already mapped.

presentation: Option<PresentationStagingBuffer>

The PresentationStagingBuffer of the most recent presentation. This will be None directly after initialization, as clearing is handled completely in the ScriptThread.

next_epoch: Epoch

Next epoch to be used

Implementations

impl ContextData

fn new( global: &Arc<Global>, buffer_ids: ArrayVec<BufferId, PRESENTATION_BUFFER_COUNT>, size: DeviceIntSize, ) -> Self

fn get_or_make_available_buffer( &mut self, config: &ContextConfiguration, ) -> Option<StagingBuffer>

Returns None if no staging buffer is unused or failure when making it available

fn destroy( self, script_sender: &GenericSender<WebGPUMsg>, paint_api: &CrossProcessPaintApi, )

Destroy the context that this ContextData represents, freeing all of its buffers, and deleting the associated WebRender image.

fn next_epoch(&mut self) -> Epoch

Advance the Epoch and return the new one.

fn replace_presentation(&mut self, presentation: PresentationStagingBuffer)

If the given PresentationStagingBuffer is for a newer presentation, replace the existing one. Deallocate the older one by calling Self::return_staging_buffer on it.

fn clear_presentation(&mut self)

fn return_staging_buffer(&mut self, staging_buffer: StagingBuffer)