commit cdf6cbc6595a675c01e112833d074eb0e22d037c
author Alec Mouri <alecmouri@google.com> Mon Nov 01 17:21:15 2021 -0700
committer Alec Mouri <alecmouri@google.com> Thu Dec 09 18:26:38 2021 -0800
tree 526f055612a7b94b3a9e2fa49692747bfe0f1d42
parent 2b1212b9b1d626a7d8da530429a660db33c4c7e6

End-to-end plumbing for dimming SDR layers

Model here is:
* HDR luminance is set to the current display brightness
* SDR luminance is set to the current SDR white point reported by
DisplayManager

Ideally we use scene-referred white points instead, so:
* PQ is always 10k nits
* HLG is always 1k nits
* Everything else is 150-200 nits

So relative dimming thresholds are fixed. But right now this is visually
less jarring (otherwise youtube UI will suddenly dim when autoplaying
HDR video).

Bug: 200310158
Test: Verified that plumbing sdr white point is sent to renderengine
Test: librenderengine_test
Test: libcompositionengine_test
Test: DataspaceUtils_test

Change-Id: I5bcea7941935c43e57cd5434e1ec69b41d31f2b4

services/surfaceflinger/DisplayHardware/HWComposer.cpp

diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.cpp b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
index 06f5df5..d851e22 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.cpp
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
@@ -522,11 +522,13 @@
     RETURN_IF_HWC_ERROR_FOR("getRequests", error, displayId, BAD_INDEX);
 
     DeviceRequestedChanges::ClientTargetProperty clientTargetProperty;
-    error = hwcDisplay->getClientTargetProperty(&clientTargetProperty);
+    float clientTargetWhitePointNits;
+    error = hwcDisplay->getClientTargetProperty(&clientTargetProperty, &clientTargetWhitePointNits);
 
     outChanges->emplace(DeviceRequestedChanges{std::move(changedTypes), std::move(displayRequests),
                                                std::move(layerRequests),
-                                               std::move(clientTargetProperty)});
+                                               std::move(clientTargetProperty),
+                                               clientTargetWhitePointNits});
     error = hwcDisplay->acceptChanges();
     RETURN_IF_HWC_ERROR_FOR("acceptChanges", error, displayId, BAD_INDEX);