kc3-lang/angle

2023-02-16T23:16:46

Vulkan: Don't close render pass if rebind to same fbo In the Vulkan backend, the render pass can occasionally (and transiently) be in a state of "open but inactive". This is when the render pass is closed, but has the potential for future modifications (for example to add a resolve attachment). Under many circumstances, it is expected that an open render pass cannot be in such a state. This assumption can be broken in this scenario: - Open render pass, draw, etc - Change framebuffer binding - Change framebuffer binding back to original - Masked Clear When ContextVk is synced before clear, it sees that the framebuffer binding is changed (though it hasn't really), and it closes the render passes and sets the render pass dirty bit. If a draw were to follow, a new render pass would have started (unnecessarily). However, in the case of a masked clear, UtilsVk notices that the render pass is started, assumes it must be active, and continues recording to it. While the operation itself succeeds, the assumption that the render pass is active is false (and fails assertion). This change makes sure that framebuffer binding change is no-oped if the framebuffer is the same one that has opened the current render pass. If any application does unnecessary binding changes and back, it will be optimized by this change as well. Bug: chromium:1411210 Change-Id: I37a3a9f2eaa1a81a1b3393840b9458ec71a87377 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4261215 Reviewed-by: Charlie Lao <cclao@google.com> Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>