On Mon, Jan 3, 2022 at 10:04 PM Ramin Halavati <rhalav...@google.com> wrote:
> I don't need the precise damaged region and unioned rect suffices. > I'm still considering possibilities for the triggering mechanism and have > not found a good one yet. It would be great if you suggest options that I > take a closer look at. > > Which process is managing the image processing module? I'm assuming it's the browser so you'll need a mechanism for the browser process to be notified when the web content updates and a new snapshot is available. By default the browser doesn't receive such notifications, frames go directly from the renderer to Viz/GPU and then the display. You'd need to attach a listener to a FrameSink whose frames you want to capture. The sink could be 1:1 with the web content for a particular tab, a browser window or the whole display (in the case of CrOS). The closest use-case to this is FrameSinkVideoCapturer <https://source.chromium.org/chromium/chromium/src/+/main:services/viz/privileged/mojom/compositing/frame_sink_video_capture.mojom;l=95;drc=c8c461cb5a5714f0c529b07913511ee54d129e7b>. It's worth looking through the source code for how it's used. cc-ing some GPU folks who might have additional pointers. > Thanks, > Ramin > > On Mon, Jan 3, 2022 at 5:00 PM Khushal Sagar <khushalsa...@chromium.org> > wrote: > >> Are you looking for the precise damaged region (list of rectangles) or >> would a unioned rect suffice? Damage tracking in the compositing stack >> tracks the latter. >> >> Also, how is the snapshot getting triggered? That'll help in pointing out >> the easiest way to get this information. >> >> On Thu, Dec 30, 2021 at 11:07 PM Ramin Halavati <rhalav...@chromium.org> >> wrote: >> >>> Hi! >>> >>> I am working on a proposal for an accessibility module that takes >>> snapshots of the screen and annotates them through a local image processing >>> module. >>> >> To do so, I need to have triggers that say "this region of the screen is >>> updated". I've looked into several positions for the trigger (like >>> ui::Window::SchedulePaintInRect oand >>> cc::AsyncLayerTreeFrameSink::SubmitCompositorFrame) but could not find a >>> place that gives me the content area rectangles that are updated. I would >>> appreciate any pointers on where to look. >>> >>> Thank you, >>> Ramin >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "blink-dev" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to blink-dev+unsubscr...@chromium.org. >>> To view this discussion on the web visit >>> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAMgMY8wzFGBpai2sX1bE5rjyZtM2B-NKtiACzr0V3GDRn9h6WQ%40mail.gmail.com >>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAMgMY8wzFGBpai2sX1bE5rjyZtM2B-NKtiACzr0V3GDRn9h6WQ%40mail.gmail.com?utm_medium=email&utm_source=footer> >>> . >>> >> -- You received this message because you are subscribed to the Google Groups "blink-dev" group. To unsubscribe from this group and stop receiving emails from it, send an email to blink-dev+unsubscr...@chromium.org. To view this discussion on the web visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAMLuWUx1jqE5T7DbhbQktkFA3M36wNC-akJuKbQMDmGnYQ4ysg%40mail.gmail.com.
