commit fb069305e90947aeb76b72527f23aa24564f3c87
author Peiyong Lin <lpy@google.com> Wed Apr 25 14:34:31 2018 -0700
committer Peiyong Lin <lpy@google.com> Wed May 02 10:56:11 2018 -0700
tree 45a22b91bce96a44053931f0396ae81f6b6fc3ce
parent af0c783042eb89b58abb28bda87e4dd298af725f

[SurfaceFlinger] Adapt min/max luminance from hardware composer.

The luminance capability of the display is very important to HDR content.
Previously, the minimum and maximum luminance were assumed as 0.0 and 500.0
respectively. This patch adapts the value returned from hardware composer and
plumbs the value to RenderEngine. If hardware composer doesn't return valid
values, 0.0 and 500.0 are still used as minimum and maximum luminance
respectively.

BUG: 73825729
BUG: 78574325
Test: Build, flash, watch video.
Change-Id: Ie1dc93f5cca7068580d6ae19da43346491196d7c

services/surfaceflinger/DisplayDevice.h

diff --git a/services/surfaceflinger/DisplayDevice.h b/services/surfaceflinger/DisplayDevice.h
index df5d945..1df8c49 100644
--- a/services/surfaceflinger/DisplayDevice.h
+++ b/services/surfaceflinger/DisplayDevice.h
@@ -27,6 +27,7 @@
 #include <gui/ISurfaceComposer.h>
 #include <hardware/hwcomposer_defs.h>
 #include <ui/GraphicTypes.h>
+#include <ui/HdrCapabilities.h>
 #include <ui/Region.h>
 #include <utils/RefBase.h>
 #include <utils/Mutex.h>
@@ -53,6 +54,9 @@
 class DisplayDevice : public LightRefBase<DisplayDevice>
 {
 public:
+    constexpr static float sDefaultMinLumiance = 0.0;
+    constexpr static float sDefaultMaxLumiance = 500.0;
+
     // region in layer-stack space
     mutable Region dirtyRegion;
     // region in screen space
@@ -141,6 +145,13 @@
     bool hasHDR10Support() const { return mHasHdr10; }
     bool hasHLGSupport() const { return mHasHLG; }
     bool hasDolbyVisionSupport() const { return mHasDolbyVision; }
+    // The returned HdrCapabilities is the combination of HDR capabilities from
+    // hardware composer and RenderEngine. When the DisplayDevice supports wide
+    // color gamut, RenderEngine is able to simulate HDR support in Display P3
+    // color space for both PQ and HLG HDR contents. The minimum and maximum
+    // luminance will be set to sDefaultMinLumiance and sDefaultMaxLumiance
+    // respectively if hardware composer doesn't return meaningful values.
+    const HdrCapabilities& getHdrCapabilities() const { return mHdrCapabilities; }
 
     void swapBuffers(HWComposer& hwc) const;
 
@@ -261,7 +272,7 @@
     bool mHasHdr10;
     bool mHasHLG;
     bool mHasDolbyVision;
-
+    HdrCapabilities mHdrCapabilities;
     const int32_t mSupportedPerFrameMetadata;
 };
 
@@ -309,6 +320,9 @@
     ui::Dataspace getDataSpace() const override {
         return mDevice->getCompositionDataSpace();
     }
+    float getDisplayMaxLuminance() const override {
+        return mDevice->getHdrCapabilities().getDesiredMaxLuminance();
+    }
 
 private:
     const sp<const DisplayDevice> mDevice;