[Impeller] Turned on new blur.

[gaaclarke]

This new blur should perform faster since it scales down the image before blurring it. Jonah did early testing of it and found it to be faster. Scrolling around with the blur perf bug it seems faster. It also has a wider test bed and is hopefully easier to maintain since it contains all of its logic for both directions.

testing: There are existing blur tests and we've backfilled more as we've added features to this blur.

fixes flutter/flutter#131580
fixes flutter/flutter#138259

Pre-launch Checklist

• I read the Contributor Guide and followed the process outlined there for submitting PRs.
• I read the Tree Hygiene wiki page, which explains my responsibilities.
• I read and followed the Flutter Style Guide and the C++, Objective-C, Java style guides.
• I listed at least one issue that this PR fixes in the description above.
• I added new tests to check the change I am making or feature I am adding, or the PR is test-exempt. See testing the engine for instructions on writing and running engine tests.
• I updated/added relevant documentation (doc comments with ///).
• I signed the CLA.
• All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-new channel on Discord.

[gaaclarke]

Here are the tests that currently need addressing. Fixing the clipped blur failures may also help with flutter/flutter#139165. Some of it seems related to clamping the blur sigma too, where the old blur does it, and the new one doesn't.

[gaaclarke]

This is looking good now except for the case where we aren't clamping the sigma.

[flutter-dashboard]

Golden file changes are available for triage from new commit, Click here to view.

Changes reported for pull request #48472 at sha e6fc470

[gaaclarke]

We still have a few outstanding optimizations we could do. I think this is feature complete enough to land. I did manual testing with the blur perf bug's sample code and wonderous.

[jonahwilliams]

LGTM!

[gaaclarke]

Here are the results from backdrop_filter_perf_ios__timeline_summary. Despite earlier positive early results the new blur seems to be slower too. We should implement some of our planned optimizations before switching over.

before

    "average_vsync_transitions_missed": 3.861904761904762,
    "90th_percentile_vsync_transitions_missed": 4.0,
    "99th_percentile_vsync_transitions_missed": 4.0,
    "average_vsync_frame_lag": 0.0,
    "90th_percentile_vsync_frame_lag": 0.0,
    "99th_percentile_vsync_frame_lag": 0.0,
    "average_layer_cache_count": 0.0,
    "90th_percentile_layer_cache_count": 0.0,
    "99th_percentile_layer_cache_count": 0.0,
    "average_frame_request_pending_latency": 16648.66,
    "90th_percentile_frame_request_pending_latency": 16720.0,
    "99th_percentile_frame_request_pending_latency": 16783.0,
    "worst_layer_cache_count": 0.0,
    "average_layer_cache_memory": 0.0,
    "90th_percentile_layer_cache_memory": 0.0,
    "99th_percentile_layer_cache_memory": 0.0,
    "worst_layer_cache_memory": 0.0,
    "average_picture_cache_count": 0.0,
    "90th_percentile_picture_cache_count": 0.0,
    "99th_percentile_picture_cache_count": 0.0,
    "worst_picture_cache_count": 0.0,
    "average_picture_cache_memory": 0.0,
    "90th_percentile_picture_cache_memory": 0.0,
    "99th_percentile_picture_cache_memory": 0.0,
    "worst_picture_cache_memory": 0.0,
    "total_ui_gc_time": 0.119,
    "30hz_frame_percentage": 0.0,
    "60hz_frame_percentage": 100.0,
    "80hz_frame_percentage": 0.0,
    "90hz_frame_percentage": 0.0,
    "120hz_frame_percentage": 0.0,
    "illegal_refresh_rate_frame_count": 0,
    "average_gpu_frame_time": 51.48809523809524,
    "90th_percentile_gpu_frame_time": 62.5,
    "99th_percentile_gpu_frame_time": 62.5,
    "worst_gpu_frame_time": 62.5,
    "average_cpu_usage": 97.33600004000002,
    "90th_percentile_cpu_usage": 99.100001,
    "99th_percentile_cpu_usage": 99.400001,
    "average_gpu_usage": 100.0,
    "90th_percentile_gpu_usage": 100.0,
    "99th_percentile_gpu_usage": 100.0,
    "average_memory_usage": 118.8809375,
    "90th_percentile_memory_usage": 139.796875,
    "99th_percentile_memory_usage": 145.390625
  },

after

    "average_vsync_transitions_missed": 5.830645161290323,
    "90th_percentile_vsync_transitions_missed": 6.0,
    "99th_percentile_vsync_transitions_missed": 6.0,
    "average_vsync_frame_lag": 0.0,
    "90th_percentile_vsync_frame_lag": 0.0,
    "99th_percentile_vsync_frame_lag": 0.0,
    "average_layer_cache_count": 0.0,
    "90th_percentile_layer_cache_count": 0.0,
    "99th_percentile_layer_cache_count": 0.0,
    "average_frame_request_pending_latency": 16638.835,
    "90th_percentile_frame_request_pending_latency": 16727.0,
    "99th_percentile_frame_request_pending_latency": 16772.0,
    "worst_layer_cache_count": 0.0,
    "average_layer_cache_memory": 0.0,
    "90th_percentile_layer_cache_memory": 0.0,
    "99th_percentile_layer_cache_memory": 0.0,
    "worst_layer_cache_memory": 0.0,
    "average_picture_cache_count": 0.0,
    "90th_percentile_picture_cache_count": 0.0,
    "99th_percentile_picture_cache_count": 0.0,
    "worst_picture_cache_count": 0.0,
    "average_picture_cache_memory": 0.0,
    "90th_percentile_picture_cache_memory": 0.0,
    "99th_percentile_picture_cache_memory": 0.0,
    "worst_picture_cache_memory": 0.0,
    "total_ui_gc_time": 2.286,
    "30hz_frame_percentage": 0.0,
    "60hz_frame_percentage": 100.0,
    "80hz_frame_percentage": 0.0,
    "90hz_frame_percentage": 0.0,
    "120hz_frame_percentage": 0.0,
    "illegal_refresh_rate_frame_count": 0,
    "average_gpu_frame_time": 87.70161290322581,
    "90th_percentile_gpu_frame_time": 125.0,
    "99th_percentile_gpu_frame_time": 125.0,
    "worst_gpu_frame_time": 125.0,
    "average_cpu_usage": 118.07500012500005,
    "90th_percentile_cpu_usage": 126.800002,
    "99th_percentile_cpu_usage": 129.600001,
    "average_gpu_usage": 100.0,
    "90th_percentile_gpu_usage": 100.0,
    "99th_percentile_gpu_usage": 100.0,
    "average_memory_usage": 104.82259114583333,
    "90th_percentile_memory_usage": 119.875,
    "99th_percentile_memory_usage": 123.8125
  },

[bdero]

I opened the EntityTest.GaussianBlurFilter playground in xcode and it's leaking like a firehose. Not sure if it's at all relevant to the reason for revert or if it's just a problem with this playground, but it doesn't seem to be happening for other interactive playgrounds

[gaaclarke]

I opened the EntityTest.GaussianBlurFilter playground in xcode and it's leaking like a firehose. Not sure if it's at all relevant to the reason for revert or if it's just a problem with this playground, but it doesn't seem to be happening for other interactive playgrounds

I called this out the other week when I left it running when I went to lunch and it almost took down my computer. I did measurements for the benchmark in flutter/flutter#140189 (comment). I didn't post the results but I looked at cpu results too and they looked stable. So I think this leak is unique to the interactive test.

[jason-simmons]

Landed a fix for the leak described in #48472 (comment)

(The issue only affects the playground framework - see #49576)