Make EllipseOverlapDetector configurable (f28f635a) · Commits · e / os / android_frameworks_base

core/res/res/values/config.xml

+20 −0

Original line number	Diff line number	Diff line
		@@ -4979,6 +4979,26 @@
		-->
		</integer-array>

		<!-- The properties for handling UDFPS touch detection
		<string-array name="config_udfps_touch_detection_options">
		<item>[detector_type],[sensor_shape],[target_size],[min_ellipse_overlap_percentage]</item>
		</string-array>

		[detector_type]: 0 for bounding box detector, 1 for ellipse detector
		[sensor_shape]: 0 for square, 1 for circle
		[target_size]: percentage (defined as a float of 0-1) of sensor that is considered the target, expands outward from center
		[min_ellipse_overlap_percentage]: minimum percentage (float from 0-1) needed to be considered a valid overlap
		[step_size]: size of each step when iterating over sensor pixel grid
		-->
		<string-array name="config_udfps_touch_detection_options">
		<item>0,0,1.0,0,1</item>
		<item>1,1,1.0,0,1</item>
		<item>1,1,1.0,.4,1</item>
		</string-array>

		<!-- The integer index of the selected option in config_udfps_touch_detection_options -->
		<integer name="config_selected_udfps_touch_detection">2</integer>

		<!-- An array of arrays of side fingerprint sensor properties relative to each display.
		Note: this value is temporary and is expected to be queried directly
		from the HAL in the future. -->

core/res/res/values/symbols.xml

+2 −0

Original line number	Diff line number	Diff line
		@@ -2646,6 +2646,8 @@
		<java-symbol type="array" name="config_biometric_sensors" />
		<java-symbol type="bool" name="allow_test_udfps" />
		<java-symbol type="array" name="config_udfps_sensor_props" />
		<java-symbol type="array" name="config_udfps_touch_detection_options" />
		<java-symbol type="integer" name="config_selected_udfps_touch_detection" />
		<java-symbol type="array" name="config_sfps_sensor_props" />
		<java-symbol type="bool" name="config_is_powerbutton_fps" />
		<java-symbol type="array" name="config_udfps_enroll_stage_thresholds" />

packages/SystemUI/src/com/android/systemui/biometrics/EllipseOverlapDetectorParams.kt

0 → 100644

+13 −0

Original line number	Diff line number	Diff line
		package com.android.systemui.biometrics

		/**
		* Collection of parameters used by EllipseOverlapDetector
		*
		* [minOverlap] minimum percentage (float from 0-1) needed to be considered a valid overlap
		*
		* [targetSize] percentage (defined as a float of 0-1) of sensor that is considered the target,
		* expands outward from center
		*
		* [stepSize] size of each step when iterating over sensor pixel grid
		*/
		class EllipseOverlapDetectorParams(val minOverlap: Float, val targetSize: Float, val stepSize: Int)

packages/SystemUI/src/com/android/systemui/biometrics/dagger/UdfpsModule.kt

+26 −3

Original line number	Diff line number	Diff line
		@@ -16,6 +16,9 @@

		package com.android.systemui.biometrics.dagger

		import android.content.res.Resources
		import com.android.internal.R
		import com.android.systemui.biometrics.EllipseOverlapDetectorParams
		import com.android.systemui.biometrics.udfps.BoundingBoxOverlapDetector
		import com.android.systemui.biometrics.udfps.EllipseOverlapDetector
		import com.android.systemui.biometrics.udfps.OverlapDetector
		@@ -33,11 +36,31 @@ interface UdfpsModule {
		@Provides
		@SysUISingleton
		fun providesOverlapDetector(featureFlags: FeatureFlags): OverlapDetector {
		return if (featureFlags.isEnabled(Flags.UDFPS_ELLIPSE_DETECTION)) {
		EllipseOverlapDetector()
		if (featureFlags.isEnabled(Flags.UDFPS_ELLIPSE_DETECTION)) {
		val selectedOption =
		Resources.getSystem()
		.getInteger(R.integer.config_selected_udfps_touch_detection)
		val values =
		Resources.getSystem()
		.getStringArray(R.array.config_udfps_touch_detection_options)[
		selectedOption]
		.split(",")
		.map { it.toFloat() }

		return if (values[0] == 1f) {
		EllipseOverlapDetector(
		EllipseOverlapDetectorParams(
		minOverlap = values[3],
		targetSize = values[2],
		stepSize = values[4].toInt()
		)
		)
		} else {
		BoundingBoxOverlapDetector()
		}
		} else {
		return BoundingBoxOverlapDetector()
		}
		}
		}
		}

packages/SystemUI/src/com/android/systemui/biometrics/udfps/EllipseOverlapDetector.kt

+70 −28

Original line number	Diff line number	Diff line
		@@ -18,22 +18,84 @@ package com.android.systemui.biometrics.udfps

		import android.graphics.Point
		import android.graphics.Rect
		import androidx.annotation.VisibleForTesting
		import android.util.Log
		import com.android.systemui.biometrics.EllipseOverlapDetectorParams
		import com.android.systemui.dagger.SysUISingleton
		import kotlin.math.cos
		import kotlin.math.pow
		import kotlin.math.sin

		private enum class SensorPixelPosition {
		OUTSIDE, // Pixel that falls outside of sensor circle
		SENSOR, // Pixel within sensor circle
		TARGET // Pixel within sensor center target
		}

		private val isDebug = true
		private val TAG = "EllipseOverlapDetector"

		/**
		* Approximates the touch as an ellipse and determines whether the ellipse has a sufficient overlap
		* with the sensor.
		*/
		@SysUISingleton
		class EllipseOverlapDetector(private val neededPoints: Int = 2) : OverlapDetector {

		class EllipseOverlapDetector(private val params: EllipseOverlapDetectorParams) : OverlapDetector {
		override fun isGoodOverlap(touchData: NormalizedTouchData, nativeSensorBounds: Rect): Boolean {
		val points = calculateSensorPoints(nativeSensorBounds)
		return points.count { checkPoint(it, touchData) } >= neededPoints
		var isTargetTouched = false
		var sensorPixels = 0
		var coveredPixels = 0
		for (y in nativeSensorBounds.top..nativeSensorBounds.bottom step params.stepSize) {
		for (x in nativeSensorBounds.left..nativeSensorBounds.right step params.stepSize) {
		// Check where pixel is within the sensor TODO: (b/265836919) This could be improved
		// by precomputing these points
		val pixelPosition =
		isPartOfSensorArea(
		x,
		y,
		nativeSensorBounds.centerX(),
		nativeSensorBounds.centerY(),
		nativeSensorBounds.width() / 2
		)
		if (pixelPosition != SensorPixelPosition.OUTSIDE) {
		sensorPixels++

		// Check if this pixel falls within ellipse touch
		if (checkPoint(Point(x, y), touchData)) {
		coveredPixels++

		// Check that at least one covered pixel is within sensor target
		isTargetTouched =
		isTargetTouched or (pixelPosition == SensorPixelPosition.TARGET)
		}
		}
		}
		}

		val percentage: Float = coveredPixels.toFloat() / sensorPixels
		if (isDebug) {
		Log.v(
		TAG,
		"covered: $coveredPixels, sensor: $sensorPixels, " +
		"percentage: $percentage, isCenterTouched: $isTargetTouched"
		)
		}

		return percentage >= params.minOverlap && isTargetTouched
		}

		/** Checks if point is in the sensor center target circle, outer circle, or outside of sensor */
		private fun isPartOfSensorArea(x: Int, y: Int, cX: Int, cY: Int, r: Int): SensorPixelPosition {
		val dx = cX - x
		val dy = cY - y

		val disSquared = dx * dx + dy * dy

		return if (disSquared <= (r * params.targetSize) * (r * params.targetSize)) {
		SensorPixelPosition.TARGET
		} else if (disSquared <= r * r) {
		SensorPixelPosition.SENSOR
		} else {
		SensorPixelPosition.OUTSIDE
		}
		}

		private fun checkPoint(point: Point, touchData: NormalizedTouchData): Boolean {
		@@ -45,29 +107,9 @@ class EllipseOverlapDetector(private val neededPoints: Int = 2) : OverlapDetecto
		val c: Float = sin(touchData.orientation) * (point.x - touchData.x)
		val d: Float = cos(touchData.orientation) * (point.y - touchData.y)
		val result =
		(a + b).pow(2) / (touchData.minor / 2).pow(2) +
		(c - d).pow(2) / (touchData.major / 2).pow(2)
		(a + b) * (a + b) / ((touchData.minor / 2) * (touchData.minor / 2)) +
		(c - d) * (c - d) / ((touchData.major / 2) * (touchData.major / 2))

		return result <= 1
		}

		@VisibleForTesting
		fun calculateSensorPoints(sensorBounds: Rect): List<Point> {
		val sensorX = sensorBounds.centerX()
		val sensorY = sensorBounds.centerY()
		val cornerOffset: Int = sensorBounds.width() / 4
		val sideOffset: Int = sensorBounds.width() / 3

		return listOf(
		Point(sensorX - cornerOffset, sensorY - cornerOffset),
		Point(sensorX, sensorY - sideOffset),
		Point(sensorX + cornerOffset, sensorY - cornerOffset),
		Point(sensorX - sideOffset, sensorY),
		Point(sensorX, sensorY),
		Point(sensorX + sideOffset, sensorY),
		Point(sensorX - cornerOffset, sensorY + cornerOffset),
		Point(sensorX, sensorY + sideOffset),
		Point(sensorX + cornerOffset, sensorY + cornerOffset)
		)
		}
		}