On Fri, Sep 5, 2008 at 6:13 AM, Brett Wilson <[EMAIL PROTECTED]> wrote:
> > On Sep 3, 9:56 pm, "Mark Wang" <[EMAIL PROTECTED]> wrote: > > The render processes paint to offscreen DCs. Each render process (ie, > tab) > > retains its own DC. > > This isn't true. Each render process paints into a new DC every time > we paint, and it gets sent to the browser process. > > >Handles to the (offscreen) bitmap are passed in the IPC > > messages. (But not the actual bitmaps themselves.) The main browser > > process takes care of presenting those bitmaps in turn, on screen. > > The browser process keeps a copy of the contents of the foreground > tabs, and maybe a few background ones as well in a cache. It gets > paint and scroll events from the renderer, and updates this bitmap > with the new information (for example, a paint might only be a small > portion of the screen, and only this changed area will be sent by the > renderer to the browser). This bitmap is a device dependent bitmap on > the video card so scrolling and copying it to the screen is quick. > minor correction: not a device dependent bitmap anymore. it is a device independent bitmap now. DDBs are problematic in that they take up space in the memory alloted to the desktop, and that can have a very low limit. it can be very problematic for the entire desktop if that limit is reached or if enough of it is used such that other allocations fail (it is typical for apps to ask for large transcient DDBs). so it is not a good idea to keep DDBs hanging around for long. -darin > > > Thumbnail generation is done in RenderView::CaptureThumbnail in response > to > > a message: an image is resized within the render process and the (actual) > > thumbnail is IPCed to the main process for the "most visited" welcome > > screen. > > Yes > > > Also for the tab dragging, in the browser process > > HWNDPhotobooth::PaintScreenshotIntoCanvas takes the HWND of the tab being > > dragged, "captures" it, (which is then downsampled in > > SkBitmap::buildMipMap) and then paints it into a layered window which is > > what is shown during dragging. > > Yup. > > Brett > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Chromium-dev" group. To post to this group, send email to chromium-dev@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/chromium-dev?hl=en -~----------~----~----~----~------~----~------~--~---
