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
diff --git a/services/surfaceflinger/DisplayHardware/AidlComposerHal.cpp b/services/surfaceflinger/DisplayHardware/AidlComposerHal.cpp
index 200bb65..29e5a74 100644
--- a/services/surfaceflinger/DisplayHardware/AidlComposerHal.cpp
+++ b/services/surfaceflinger/DisplayHardware/AidlComposerHal.cpp
@@ -1005,12 +1005,19 @@
 }
 
 Error AidlComposer::getClientTargetProperty(
-        Display display, IComposerClient::ClientTargetProperty* outClientTargetProperty) {
+        Display display, IComposerClient::ClientTargetProperty* outClientTargetProperty,
+        float* whitePointNits) {
     ClientTargetProperty property;
-    mReader.takeClientTargetProperty(translate<int64_t>(display), &property);
+    mReader.takeClientTargetProperty(translate<int64_t>(display), &property, whitePointNits);
     *outClientTargetProperty = translate<IComposerClient::ClientTargetProperty>(property);
     return Error::NONE;
 }
 
+Error AidlComposer::setLayerWhitePointNits(Display display, Layer layer, float whitePointNits) {
+    mWriter.setLayerWhitePointNits(translate<int64_t>(display), translate<int64_t>(layer),
+                                   whitePointNits);
+    return Error::NONE;
+}
+
 } // namespace Hwc2
 } // namespace android
diff --git a/services/surfaceflinger/DisplayHardware/AidlComposerHal.h b/services/surfaceflinger/DisplayHardware/AidlComposerHal.h
index 418a8cc..8cae25f 100644
--- a/services/surfaceflinger/DisplayHardware/AidlComposerHal.h
+++ b/services/surfaceflinger/DisplayHardware/AidlComposerHal.h
@@ -194,9 +194,10 @@
                                         bool mandatory, const std::vector<uint8_t>& value) override;
     V2_4::Error getLayerGenericMetadataKeys(
             std::vector<IComposerClient::LayerGenericMetadataKey>* outKeys) override;
-    Error getClientTargetProperty(
-            Display display,
-            IComposerClient::ClientTargetProperty* outClientTargetProperty) override;
+    Error getClientTargetProperty(Display display,
+                                  IComposerClient::ClientTargetProperty* outClientTargetProperty,
+                                  float* outClientTargetWhitePointNits) override;
+    Error setLayerWhitePointNits(Display display, Layer layer, float whitePointNits) override;
 
 private:
     // Many public functions above simply write a command into the command
diff --git a/services/surfaceflinger/DisplayHardware/ComposerHal.h b/services/surfaceflinger/DisplayHardware/ComposerHal.h
index 3bbce7b..3cc5e5e 100644
--- a/services/surfaceflinger/DisplayHardware/ComposerHal.h
+++ b/services/surfaceflinger/DisplayHardware/ComposerHal.h
@@ -221,7 +221,11 @@
     virtual V2_4::Error getLayerGenericMetadataKeys(
             std::vector<IComposerClient::LayerGenericMetadataKey>* outKeys) = 0;
     virtual Error getClientTargetProperty(
-            Display display, IComposerClient::ClientTargetProperty* outClientTargetProperty) = 0;
+            Display display, IComposerClient::ClientTargetProperty* outClientTargetProperty,
+            float* outWhitePointNits) = 0;
+
+    // AIDL Composer
+    virtual Error setLayerWhitePointNits(Display display, Layer layer, float whitePointNits) = 0;
 };
 
 } // namespace android::Hwc2
diff --git a/services/surfaceflinger/DisplayHardware/HWC2.cpp b/services/surfaceflinger/DisplayHardware/HWC2.cpp
index e21b0da..596666c 100644
--- a/services/surfaceflinger/DisplayHardware/HWC2.cpp
+++ b/services/surfaceflinger/DisplayHardware/HWC2.cpp
@@ -555,8 +555,10 @@
     return static_cast<Error>(intError);
 }
 
-Error Display::getClientTargetProperty(ClientTargetProperty* outClientTargetProperty) {
-    const auto error = mComposer.getClientTargetProperty(mId, outClientTargetProperty);
+Error Display::getClientTargetProperty(ClientTargetProperty* outClientTargetProperty,
+                                       float* outWhitePointNits) {
+    const auto error =
+            mComposer.getClientTargetProperty(mId, outClientTargetProperty, outWhitePointNits);
     return static_cast<Error>(error);
 }
 
@@ -919,6 +921,16 @@
     return static_cast<Error>(intError);
 }
 
+// AIDL HAL
+Error Layer::setWhitePointNits(float whitePointNits) {
+    if (CC_UNLIKELY(!mDisplay)) {
+        return Error::BAD_DISPLAY;
+    }
+
+    auto intError = mComposer.setLayerWhitePointNits(mDisplay->getId(), mId, whitePointNits);
+    return static_cast<Error>(intError);
+}
+
 } // namespace impl
 } // namespace HWC2
 } // namespace android
diff --git a/services/surfaceflinger/DisplayHardware/HWC2.h b/services/surfaceflinger/DisplayHardware/HWC2.h
index a65efb2..5e0ba06 100644
--- a/services/surfaceflinger/DisplayHardware/HWC2.h
+++ b/services/surfaceflinger/DisplayHardware/HWC2.h
@@ -146,7 +146,7 @@
             std::vector<hal::ContentType>*) const = 0;
     [[clang::warn_unused_result]] virtual hal::Error setContentType(hal::ContentType) = 0;
     [[clang::warn_unused_result]] virtual hal::Error getClientTargetProperty(
-            hal::ClientTargetProperty* outClientTargetProperty) = 0;
+            hal::ClientTargetProperty* outClientTargetProperty, float* outWhitePointNits) = 0;
 };
 
 namespace impl {
@@ -209,7 +209,8 @@
     hal::Error getSupportedContentTypes(
             std::vector<hal::ContentType>* outSupportedContentTypes) const override;
     hal::Error setContentType(hal::ContentType) override;
-    hal::Error getClientTargetProperty(hal::ClientTargetProperty* outClientTargetProperty) override;
+    hal::Error getClientTargetProperty(hal::ClientTargetProperty* outClientTargetProperty,
+                                       float* outWhitePointNits) override;
 
     // Other Display methods
     hal::HWDisplayId getId() const override { return mId; }
@@ -288,6 +289,9 @@
     // Composer HAL 2.4
     [[clang::warn_unused_result]] virtual hal::Error setLayerGenericMetadata(
             const std::string& name, bool mandatory, const std::vector<uint8_t>& value) = 0;
+
+    // AIDL HAL
+    [[clang::warn_unused_result]] virtual hal::Error setWhitePointNits(float whitePointNits) = 0;
 };
 
 namespace impl {
@@ -331,6 +335,9 @@
     hal::Error setLayerGenericMetadata(const std::string& name, bool mandatory,
                                        const std::vector<uint8_t>& value) override;
 
+    // AIDL HAL
+    hal::Error setWhitePointNits(float whitePointNits) override;
+
 private:
     // These are references to data owned by HWC2::Device, which will outlive
     // this HWC2::Layer, so these references are guaranteed to be valid for
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);
 
diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.h b/services/surfaceflinger/DisplayHardware/HWComposer.h
index 0a090da..bd79977 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.h
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.h
@@ -79,6 +79,7 @@
         DisplayRequests displayRequests;
         LayerRequests layerRequests;
         ClientTargetProperty clientTargetProperty;
+        float clientTargetWhitePointNits;
     };
 
     struct HWCDisplayMode {
diff --git a/services/surfaceflinger/DisplayHardware/HidlComposerHal.cpp b/services/surfaceflinger/DisplayHardware/HidlComposerHal.cpp
index 6c40598..11d41c0 100644
--- a/services/surfaceflinger/DisplayHardware/HidlComposerHal.cpp
+++ b/services/surfaceflinger/DisplayHardware/HidlComposerHal.cpp
@@ -1164,8 +1164,14 @@
 }
 
 Error HidlComposer::getClientTargetProperty(
-        Display display, IComposerClient::ClientTargetProperty* outClientTargetProperty) {
+        Display display, IComposerClient::ClientTargetProperty* outClientTargetProperty,
+        float* outWhitePointNits) {
     mReader.takeClientTargetProperty(display, outClientTargetProperty);
+    *outWhitePointNits = -1.f;
+    return Error::NONE;
+}
+
+Error HidlComposer::setLayerWhitePointNits(Display, Layer, float) {
     return Error::NONE;
 }
 
diff --git a/services/surfaceflinger/DisplayHardware/HidlComposerHal.h b/services/surfaceflinger/DisplayHardware/HidlComposerHal.h
index ad253a2..18c0635 100644
--- a/services/surfaceflinger/DisplayHardware/HidlComposerHal.h
+++ b/services/surfaceflinger/DisplayHardware/HidlComposerHal.h
@@ -304,9 +304,10 @@
                                         bool mandatory, const std::vector<uint8_t>& value) override;
     V2_4::Error getLayerGenericMetadataKeys(
             std::vector<IComposerClient::LayerGenericMetadataKey>* outKeys) override;
-    Error getClientTargetProperty(
-            Display display,
-            IComposerClient::ClientTargetProperty* outClientTargetProperty) override;
+    Error getClientTargetProperty(Display display,
+                                  IComposerClient::ClientTargetProperty* outClientTargetProperty,
+                                  float* outWhitePointNits) override;
+    Error setLayerWhitePointNits(Display display, Layer layer, float whitePointNits) override;
 
 private:
     class CommandWriter : public CommandWriterBase {