Hi Philipp, On Fri, 27 Jul 2018 at 14:10, Philipp Zabel <[email protected]> wrote: > On Fri, 2018-07-27 at 11:23 +0100, Daniel Stone wrote: > > Taking i.MX6 as an example - if we know we can never show at least one > > view on an overlay (because it's transformed, or too many views, etc), > > then we should not waste any time and energy having that surface do a > > linear resolve. We can just skip this step and have the GPU output > > tiled and then consume tiled during composition. > > Since you mention i.MX6, it can support an alpha transparent overlay. > I have attached a patch to test this locally below, but that doesn't > check for alpha plane support. Would it be enough to check whether pixel > formats with alpha channel are advertised as supported by the plane?
To be honest, I'm not entirely sure. What I would want to check is the damage processing: that the area under the alpha-blended plane still got updated through the renderer if required. It should be pretty easy to check by putting simple-shm under an alpha-blended plane, and seeing if that got updated. Probably the tri-fan debug mode would help here as well. > > > Furthermore, we don’t have information in weston about content producing > > > device. > > > If an application wants to render with gpu, it should be responsibility > > > of the application to query and use gpu friendly modifiers. > > > We can provide them a list of scanout friendly modifiers which > > > application can use. Then, application should choose a format which would > > > work for rendering and scanout. > > > > Right, but again this may lead us to lose performance if the > > application tries to find the lowest-common-denominator layout, when > > it doesn't need to. Hence the suggestion for the compositor suggesting > > the most appropriate sets of modifiers to clients depending on the > > situation. > > Could this be used to notify Vulkan clients that they should reallocate > their swapchain for better performance, by setting swapchain status to > VK_SUBOPTIMAL_KHR? Yeah, exactly! Cheers, Daniel _______________________________________________ wayland-devel mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/wayland-devel
