From 35df7e2e1e6f049c2cc34a36ed05eb1a8fa4e49e Mon Sep 17 00:00:00 2001
From: Anthony Han <modan@google.com>
Date: Thu, 27 Jun 2019 17:27:24 -0700
Subject: [PATCH] DWB Bias splines ignore default ambient CCT

When ambientColorTemperature is set to a default of -1.0f, ambient
brightness to bias splines should ignore this values instead of trying
to interpolate to towards an actual CCT.

Bug: 132047710
Test: atest AmbientLuxTest
Change-Id: Ic6da5f80d52a94a29795a76422cc1b964cdf261b
---
 .../DisplayWhiteBalanceController.java        |  6 +++--
 .../display/whitebalance/AmbientLuxTest.java  | 27 +++++++++++++++++++
 2 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/services/core/java/com/android/server/display/whitebalance/DisplayWhiteBalanceController.java b/services/core/java/com/android/server/display/whitebalance/DisplayWhiteBalanceController.java
index dd3876d8768b3..02ec10e2d49d3 100644
--- a/services/core/java/com/android/server/display/whitebalance/DisplayWhiteBalanceController.java
+++ b/services/core/java/com/android/server/display/whitebalance/DisplayWhiteBalanceController.java
@@ -356,13 +356,15 @@ public class DisplayWhiteBalanceController implements
 
         float ambientBrightness = mBrightnessFilter.getEstimate(time);
 
-        if (mLowLightAmbientBrightnessToBiasSpline != null) {
+        if (ambientColorTemperature != -1.0f &&
+                mLowLightAmbientBrightnessToBiasSpline != null) {
             float bias = mLowLightAmbientBrightnessToBiasSpline.interpolate(ambientBrightness);
             ambientColorTemperature =
                     bias * ambientColorTemperature + (1.0f - bias)
                     * mLowLightAmbientColorTemperature;
         }
-        if (mHighLightAmbientBrightnessToBiasSpline != null) {
+        if (ambientColorTemperature != -1.0f &&
+                mHighLightAmbientBrightnessToBiasSpline != null) {
             float bias = mHighLightAmbientBrightnessToBiasSpline.interpolate(ambientBrightness);
             ambientColorTemperature =
                     (1.0f - bias) * ambientColorTemperature + bias
diff --git a/services/tests/servicestests/src/com/android/server/display/whitebalance/AmbientLuxTest.java b/services/tests/servicestests/src/com/android/server/display/whitebalance/AmbientLuxTest.java
index 424142c56b3af..6b0798bdce228 100644
--- a/services/tests/servicestests/src/com/android/server/display/whitebalance/AmbientLuxTest.java
+++ b/services/tests/servicestests/src/com/android/server/display/whitebalance/AmbientLuxTest.java
@@ -359,6 +359,33 @@ public final class AmbientLuxTest {
             }
     }
 
+    @Test
+    public void testLowLight_DefaultAmbient() throws Exception {
+        final float lowerBrightness = 10.0f;
+        final float upperBrightness = 50.0f;
+        setBrightnesses(lowerBrightness, upperBrightness);
+        setBiases(0.0f, 1.0f);
+
+        DisplayWhiteBalanceController controller =
+                DisplayWhiteBalanceFactory.create(mHandler, mSensorManagerMock, mResourcesSpy);
+        final float ambientColorTemperature = -1.0f;
+        setEstimatedColorTemperature(controller, ambientColorTemperature);
+        controller.mBrightnessFilter = spy(controller.mBrightnessFilter);
+
+        for (float t = 0.0f; t <= 1.0f; t += 0.1f) {
+            setEstimatedBrightnessAndUpdate(controller,
+                    mix(lowerBrightness, upperBrightness, t));
+            assertEquals(controller.mPendingAmbientColorTemperature, ambientColorTemperature,
+                        0.001);
+        }
+
+        setEstimatedBrightnessAndUpdate(controller, 0.0f);
+        assertEquals(controller.mPendingAmbientColorTemperature, ambientColorTemperature, 0.001);
+
+        setEstimatedBrightnessAndUpdate(controller, upperBrightness + 1.0f);
+        assertEquals(controller.mPendingAmbientColorTemperature, ambientColorTemperature, 0.001);
+    }
+
     void mockThrottler() {
         when(mResourcesSpy.getInteger(
                 R.integer.config_displayWhiteBalanceDecreaseDebounce)).thenReturn(0);