Support for faster brightness response to light changes.
Bug: 18572096
Change-Id: Ic9448db672b036779d16883f3476249cea45d97a
diff --git a/core/res/res/values/config.xml b/core/res/res/values/config.xml
index 68df6f1..b0869ea 100755
--- a/core/res/res/values/config.xml
+++ b/core/res/res/values/config.xml
@@ -861,10 +861,34 @@
<!-- Allow automatic adjusting of the screen brightness while dozing in low power state. -->
<bool name="config_allowAutoBrightnessWhileDozing">false</bool>
+ <!-- Stability requirements in milliseconds for accepting a new brightness level. This is used
+ for debouncing the light sensor. Different constants are used to debounce the light sensor
+ when adapting to brighter or darker environments. This parameter controls how quickly
+ brightness changes occur in response to an observed change in light level that exceeds the
+ hysteresis threshold. -->
+ <integer name="config_autoBrightnessBrighteningLightDebounce">4000</integer>
+ <integer name="config_autoBrightnessDarkeningLightDebounce">8000</integer>
+
+ <!-- Light sensor event rate in milliseconds for automatic brightness control. -->
+ <integer name="config_autoBrightnessLightSensorRate">250</integer>
+
<!-- If we allow automatic adjustment of screen brightness while dozing, how many times we want
to reduce it to preserve the battery. Value of 100% means no scaling. -->
<fraction name="config_screenAutoBrightnessDozeScaleFactor">100%</fraction>
+ <!-- When the screen is turned on, the previous estimate of the ambient light level at the time
+ the screen was turned off is restored and is used to determine the initial screen
+ brightness.
+
+ If this flag is true, then the ambient light level estimate will be promptly recomputed
+ after the warm-up interface and the screen brightness will be adjusted immediately.
+
+ If this flag is false, then the ambient light level estimate will be adjusted more
+ gradually in the same manner that normally happens when the screen is on according to the
+ brightening or dimming debounce thresholds. As a result, it may take somewhat longer to
+ adapt to the environment. This mode may be better suited for watches. -->
+ <bool name="config_autoBrightnessResetAmbientLuxAfterWarmUp">true</bool>
+
<!-- Screen brightness used to dim the screen when the user activity
timeout expires. May be less than the minimum allowed brightness setting
that can be set by the user. -->
diff --git a/core/res/res/values/symbols.xml b/core/res/res/values/symbols.xml
index bd69fb0..b676dfa 100755
--- a/core/res/res/values/symbols.xml
+++ b/core/res/res/values/symbols.xml
@@ -1586,6 +1586,7 @@
<java-symbol type="bool" name="config_useAttentionLight" />
<java-symbol type="bool" name="config_animateScreenLights" />
<java-symbol type="bool" name="config_automatic_brightness_available" />
+ <java-symbol type="bool" name="config_autoBrightnessResetAmbientLuxAfterWarmUp" />
<java-symbol type="bool" name="config_dozeAfterScreenOff" />
<java-symbol type="bool" name="config_enableActivityRecognitionHardwareOverlay" />
<java-symbol type="bool" name="config_enableFusedLocationOverlay" />
@@ -1641,6 +1642,9 @@
<java-symbol type="id" name="replace_message" />
<java-symbol type="fraction" name="config_dimBehindFadeDuration" />
<java-symbol type="fraction" name="config_screenAutoBrightnessDozeScaleFactor" />
+ <java-symbol type="integer" name="config_autoBrightnessBrighteningLightDebounce"/>
+ <java-symbol type="integer" name="config_autoBrightnessDarkeningLightDebounce"/>
+ <java-symbol type="integer" name="config_autoBrightnessLightSensorRate"/>
<java-symbol type="integer" name="config_carDockKeepsScreenOn" />
<java-symbol type="integer" name="config_criticalBatteryWarningLevel" />
<java-symbol type="integer" name="config_datause_notification_type" />
diff --git a/services/core/java/com/android/server/display/AutomaticBrightnessController.java b/services/core/java/com/android/server/display/AutomaticBrightnessController.java
index d919bf6..93d37f1 100644
--- a/services/core/java/com/android/server/display/AutomaticBrightnessController.java
+++ b/services/core/java/com/android/server/display/AutomaticBrightnessController.java
@@ -52,20 +52,9 @@
// auto-brightness adjustment setting.
private static final float SCREEN_AUTO_BRIGHTNESS_ADJUSTMENT_MAX_GAMMA = 3.0f;
- // Light sensor event rate in milliseconds.
- private static final int LIGHT_SENSOR_RATE_MILLIS = 1000;
-
// Period of time in which to consider light samples in milliseconds.
private static final int AMBIENT_LIGHT_HORIZON = 10000;
- // Stability requirements in milliseconds for accepting a new brightness level. This is used
- // for debouncing the light sensor. Different constants are used to debounce the light sensor
- // when adapting to brighter or darker environments. This parameter controls how quickly
- // brightness changes occur in response to an observed change in light level that exceeds the
- // hysteresis threshold.
- private static final long BRIGHTENING_LIGHT_DEBOUNCE = 4000;
- private static final long DARKENING_LIGHT_DEBOUNCE = 8000;
-
// Hysteresis constraints for brightening or darkening.
// The recent lux must have changed by at least this fraction relative to the
// current ambient lux before a change will be considered.
@@ -121,6 +110,22 @@
private final int mScreenBrightnessRangeMaximum;
private final float mDozeScaleFactor;
+ // Light sensor event rate in milliseconds.
+ private final int mLightSensorRate;
+
+ // Stability requirements in milliseconds for accepting a new brightness level. This is used
+ // for debouncing the light sensor. Different constants are used to debounce the light sensor
+ // when adapting to brighter or darker environments. This parameter controls how quickly
+ // brightness changes occur in response to an observed change in light level that exceeds the
+ // hysteresis threshold.
+ private final long mBrighteningLightDebounceConfig;
+ private final long mDarkeningLightDebounceConfig;
+
+ // If true immediately after the screen is turned on the controller will try to adjust the
+ // brightness based on the current sensor reads. If false, the controller will collect more data
+ // and only then decide whether to change brightness.
+ private final boolean mResetAmbientLuxAfterWarmUpConfig;
+
// Amount of time to delay auto-brightness after screen on while waiting for
// the light sensor to warm-up in milliseconds.
// May be 0 if no warm-up is required.
@@ -176,7 +181,9 @@
public AutomaticBrightnessController(Callbacks callbacks, Looper looper,
SensorManager sensorManager, Spline autoBrightnessSpline, int lightSensorWarmUpTime,
- int brightnessMin, int brightnessMax, float dozeScaleFactor) {
+ int brightnessMin, int brightnessMax, float dozeScaleFactor,
+ int lightSensorRate, long brighteningLightDebounceConfig,
+ long darkeningLightDebounceConfig, boolean resetAmbientLuxAfterWarmUpConfig) {
mCallbacks = callbacks;
mTwilight = LocalServices.getService(TwilightManager.class);
mSensorManager = sensorManager;
@@ -185,9 +192,13 @@
mScreenBrightnessRangeMaximum = brightnessMax;
mLightSensorWarmUpTimeConfig = lightSensorWarmUpTime;
mDozeScaleFactor = dozeScaleFactor;
+ mLightSensorRate = lightSensorRate;
+ mBrighteningLightDebounceConfig = brighteningLightDebounceConfig;
+ mDarkeningLightDebounceConfig = darkeningLightDebounceConfig;
+ mResetAmbientLuxAfterWarmUpConfig = resetAmbientLuxAfterWarmUpConfig;
mHandler = new AutomaticBrightnessHandler(looper);
- mAmbientLightRingBuffer = new AmbientLightRingBuffer();
+ mAmbientLightRingBuffer = new AmbientLightRingBuffer(mLightSensorRate);
if (!DEBUG_PRETEND_LIGHT_SENSOR_ABSENT) {
mLightSensor = mSensorManager.getDefaultSensor(Sensor.TYPE_LIGHT);
@@ -226,6 +237,9 @@
pw.println(" mScreenBrightnessRangeMinimum=" + mScreenBrightnessRangeMinimum);
pw.println(" mScreenBrightnessRangeMaximum=" + mScreenBrightnessRangeMaximum);
pw.println(" mLightSensorWarmUpTimeConfig=" + mLightSensorWarmUpTimeConfig);
+ pw.println(" mBrighteningLightDebounceConfig=" + mBrighteningLightDebounceConfig);
+ pw.println(" mDarkeningLightDebounceConfig=" + mDarkeningLightDebounceConfig);
+ pw.println(" mResetAmbientLuxAfterWarmUpConfig=" + mResetAmbientLuxAfterWarmUpConfig);
pw.println();
pw.println("Automatic Brightness Controller State:");
@@ -252,13 +266,13 @@
mLightSensorEnabled = true;
mLightSensorEnableTime = SystemClock.uptimeMillis();
mSensorManager.registerListener(mLightSensorListener, mLightSensor,
- LIGHT_SENSOR_RATE_MILLIS * 1000, mHandler);
+ mLightSensorRate * 1000, mHandler);
return true;
}
} else {
if (mLightSensorEnabled) {
mLightSensorEnabled = false;
- mAmbientLuxValid = false;
+ mAmbientLuxValid = !mResetAmbientLuxAfterWarmUpConfig;
mRecentLightSamples = 0;
mAmbientLightRingBuffer.clear();
mHandler.removeMessages(MSG_UPDATE_AMBIENT_LUX);
@@ -347,7 +361,7 @@
}
earliestValidTime = mAmbientLightRingBuffer.getTime(i);
}
- return earliestValidTime + BRIGHTENING_LIGHT_DEBOUNCE;
+ return earliestValidTime + mBrighteningLightDebounceConfig;
}
private long nextAmbientLightDarkeningTransition(long time) {
@@ -359,7 +373,7 @@
}
earliestValidTime = mAmbientLightRingBuffer.getTime(i);
}
- return earliestValidTime + DARKENING_LIGHT_DEBOUNCE;
+ return earliestValidTime + mDarkeningLightDebounceConfig;
}
private void updateAmbientLux() {
@@ -420,7 +434,7 @@
// should be enough time to decide whether we should actually transition to the new
// weighted ambient lux or not.
nextTransitionTime =
- nextTransitionTime > time ? nextTransitionTime : time + LIGHT_SENSOR_RATE_MILLIS;
+ nextTransitionTime > time ? nextTransitionTime : time + mLightSensorRate;
if (DEBUG) {
Slog.d(TAG, "updateAmbientLux: Scheduling ambient lux update for "
+ nextTransitionTime + TimeUtils.formatUptime(nextTransitionTime));
@@ -559,8 +573,6 @@
// Proportional extra capacity of the buffer beyond the expected number of light samples
// in the horizon
private static final float BUFFER_SLACK = 1.5f;
- private static final int DEFAULT_CAPACITY =
- (int) Math.ceil(AMBIENT_LIGHT_HORIZON * BUFFER_SLACK / LIGHT_SENSOR_RATE_MILLIS);
private float[] mRingLux;
private long[] mRingTime;
private int mCapacity;
@@ -571,8 +583,8 @@
private int mEnd;
private int mCount;
- public AmbientLightRingBuffer() {
- this(DEFAULT_CAPACITY);
+ public AmbientLightRingBuffer(long lightSensorRate) {
+ this((int) Math.ceil(AMBIENT_LIGHT_HORIZON * BUFFER_SLACK / lightSensorRate));
}
public AmbientLightRingBuffer(int initialCapacity) {
diff --git a/services/core/java/com/android/server/display/DisplayPowerController.java b/services/core/java/com/android/server/display/DisplayPowerController.java
index 78610ff..cf1f4b0 100644
--- a/services/core/java/com/android/server/display/DisplayPowerController.java
+++ b/services/core/java/com/android/server/display/DisplayPowerController.java
@@ -302,6 +302,15 @@
mAllowAutoBrightnessWhileDozingConfig = resources.getBoolean(
com.android.internal.R.bool.config_allowAutoBrightnessWhileDozing);
+ int lightSensorRate = resources.getInteger(
+ com.android.internal.R.integer.config_autoBrightnessLightSensorRate);
+ long brighteningLightDebounce = resources.getInteger(
+ com.android.internal.R.integer.config_autoBrightnessBrighteningLightDebounce);
+ long darkeningLightDebounce = resources.getInteger(
+ com.android.internal.R.integer.config_autoBrightnessDarkeningLightDebounce);
+ boolean autoBrightnessResetAmbientLuxAfterWarmUp = resources.getBoolean(
+ com.android.internal.R.bool.config_autoBrightnessResetAmbientLuxAfterWarmUp);
+
if (mUseSoftwareAutoBrightnessConfig) {
int[] lux = resources.getIntArray(
com.android.internal.R.array.config_autoBrightnessLevels);
@@ -336,7 +345,9 @@
mAutomaticBrightnessController = new AutomaticBrightnessController(this,
handler.getLooper(), sensorManager, screenAutoBrightnessSpline,
lightSensorWarmUpTimeConfig, screenBrightnessRangeMinimum,
- mScreenBrightnessRangeMaximum, dozeScaleFactor);
+ mScreenBrightnessRangeMaximum, dozeScaleFactor, lightSensorRate,
+ brighteningLightDebounce, darkeningLightDebounce,
+ autoBrightnessResetAmbientLuxAfterWarmUp);
}
}