kc3-lang/angle

2021-09-22T09:15:19

Vulkan: Only preserve buffer data when BufferVk has valid data When we receive glBufferSubData call and GPU is still accessing the buffer, we have two code paths to update data. If subData is more than half of the entire buffer range, we choose to acquire a new buffer and use DMA to copy the rest of buffer that outside of subData range from the old buffer back to the new buffer so that existing buffer data is being preserved. Otherwise we stage subData to use GPU buffer to buffer copy later on when buffer is been used. The reasoning behind is to minimize the amount of data copy. The improvement here is that if previously app called glBufferData with null pointer, we really do not have any valid data in the buffer and there is no need to preserve the existing buffer data. This CL tracks whether buffer has any valid data or not and also put this into consideration when we pick which code path to go. We also use this information to avoid preserve the existing data in BufferVk::acquireAndUpdate Bug: b/200067929 Change-Id: I266dd93bed2d3c07e3a5af3e4e613e7f6023b393 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3176500 Commit-Queue: Charlie Lao <cclao@google.com> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Tim Van Patten <timvp@google.com>