Struct webrender::screen_capture::AsyncScreenshotGrabber

pub(crate) struct AsyncScreenshotGrabber {
    scaling_textures: Vec<Texture>,
    available_pbos: Vec<PBO>,
    awaiting_readback: HashMap<AsyncScreenshotHandle, AsyncScreenshot>,
    next_pbo_handle: usize,
    mode: AsyncScreenshotGrabberMode,
}

Renderer infrastructure for capturing screenshots and scaling them asynchronously.

Fields

scaling_textures: Vec<Texture>

The textures used to scale screenshots.

available_pbos: Vec<PBO>

PBOs available to be used for screenshot readback.

awaiting_readback: HashMap<AsyncScreenshotHandle, AsyncScreenshot>

PBOs containing screenshots that are awaiting readback.

next_pbo_handle: usize

The handle for the net PBO that will be inserted into in_use_pbos.

mode: AsyncScreenshotGrabberMode

The mode the grabber operates in.

Implementations

impl AsyncScreenshotGrabber

pub fn new_composition_recorder() -> Self

Create a new AsyncScreenshotGrabber for the composition recorder.

pub fn deinit(self, device: &mut Device)

Deinitialize the allocated textures and PBOs.

pub fn get_screenshot( &mut self, device: &mut Device, window_rect: DeviceIntRect, buffer_size: DeviceIntSize, image_format: ImageFormat ) -> (AsyncScreenshotHandle, DeviceIntSize)

Take a screenshot and scale it asynchronously.

The returned handle can be used to access the mapped screenshot data via map_and_recycle_screenshot. The returned size is the size of the screenshot.

fn scale_screenshot( &mut self, device: &mut Device, read_target: ReadTarget, read_target_rect: DeviceIntRect, buffer_size: DeviceIntSize, min_texture_size: DeviceIntSize, dest_size: DeviceIntSize, image_format: ImageFormat, level: usize )

Take the screenshot in the given ReadTarget and scale it to dest_size recursively.

Each scaling operation scales only by a factor of two to preserve quality.

Textures are scaled such that scaling_textures[n] is half the size of scaling_textures[n+1].

After the scaling completes, the final screenshot will be in scaling_textures[0].

The size of scaling_textures[0] will be increased to min_texture_size so that an optimally-sized area can be read from it.

pub fn map_and_recycle_screenshot( &mut self, device: &mut Device, handle: AsyncScreenshotHandle, dst_buffer: &mut [u8], dst_stride: usize ) -> bool

Map the contents of the screenshot given by the handle and copy it into the given buffer.

fn iter_src_buffer_chunked<'a>( &self, gl_type: GlType, src_buffer: &'a [u8], src_stride: usize ) -> Box<dyn Iterator<Item = &'a [u8]> + 'a>

Trait Implementations

impl Default for AsyncScreenshotGrabber

fn default() -> Self

Returns the “default value” for a type.