kc3-lang/angle

2020-10-06T23:29:02

Vulkan: Fold deferred clears into current clears If there are clears prior to a glClear() call, those clears were flushed (starting a new render pass) and then the clear call's clears would be applied (essentially modifying the loadOps of said render pass). The main downside of the above is that the current glClear() clears don't get a chance to be deferred. This was observed in Chrome which clears an attachment with an emulated format, then switches framebuffers. Additionally, if the render pass had already been started, the deferred clears could have become inlined instead of breaking the render pass. Although, it's unlikely for there to be deferred clears when the render pass is already open. This change first identifies which clears need to go through the draw path (scissored, masked or as workaround for driver bug). It merges the rest of the clears (that don't need the draw path) with the deferred clears. It then checks deferred clears and applies them by either: - vkCmdClearAttachments if mid RP - Start a new render pass and use loadOps, if any draw-based clear needs to follow. - Modify current RP loadOps / defer the clear Afterwards, the draw-based clears are applied. Bug: angleproject:4836 Change-Id: Id4992c78983b199734508c9d4bb18ed3195c91ec Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2455167 Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Charlie Lao <cclao@google.com>