Add lowpass fix variable, alter constants, replace for loop. (601c62fe) · Commits · e / os / android_frameworks_base

core/java/android/view/WindowOrientationListener.java

+60 −12

Original line number	Diff line number	Diff line
		@@ -240,17 +240,34 @@ public abstract class WindowOrientationListener {
		// When device is near-vertical (screen approximately facing the horizon)
		private static final int DEFAULT_TIME_CONSTANT_MS = 200;
		// When device is partially tilted towards the sky or ground
		private static final int TILTED_TIME_CONSTANT_MS = 600;
		private static final int TILTED_TIME_CONSTANT_MS = 200;
		// When device is under external acceleration, i.e. not just gravity. We heavily distrust
		// such readings.
		private static final int ACCELERATING_TIME_CONSTANT_MS = 5000;
		private static final int ACCELERATING_TIME_CONSTANT_MS = 600;

		// As is, the lowpass was creating an extra cycle in processing
		// the orientation.
		//
		//
		//
		// Y C1
		// \| /
		// \| / _C2
		// X ____\|/____
		// \|
		// \|
		// \|
		//
		// We need to make C1 become C2
		//
		private static final float FIX_LOWPASS = 1.75f;

		private static final float DEFAULT_LOWPASS_ALPHA =
		(float) SAMPLING_PERIOD_MS / (DEFAULT_TIME_CONSTANT_MS + SAMPLING_PERIOD_MS);
		(float) (FIX_LOWPASS * SAMPLING_PERIOD_MS) / (DEFAULT_TIME_CONSTANT_MS + SAMPLING_PERIOD_MS);
		private static final float TILTED_LOWPASS_ALPHA =
		(float) SAMPLING_PERIOD_MS / (TILTED_TIME_CONSTANT_MS + SAMPLING_PERIOD_MS);
		(float) (FIX_LOWPASS * SAMPLING_PERIOD_MS) / (TILTED_TIME_CONSTANT_MS + SAMPLING_PERIOD_MS);
		private static final float ACCELERATING_LOWPASS_ALPHA =
		(float) SAMPLING_PERIOD_MS / (ACCELERATING_TIME_CONSTANT_MS + SAMPLING_PERIOD_MS);
		(float) (FIX_LOWPASS * SAMPLING_PERIOD_MS) / (ACCELERATING_TIME_CONSTANT_MS + SAMPLING_PERIOD_MS);

		// The low-pass filtered accelerometer data
		private float[] mFilteredVector = new float[] {0, 0, 0};
		@@ -259,19 +276,49 @@ public abstract class WindowOrientationListener {
		return SURFACE_ROTATIONS[mRotation];
		}

		private void calculateNewRotation(int orientation, int tiltAngle) {
		if (localLOGV) Log.i(TAG, orientation + ", " + tiltAngle + ", " + mRotation);
		private int testThreshold(int orientation){
		// This is based on the fact that our threshold ranges
		// are static. There is no reason to loop through them
		// every time. That would make our runtime O(n).
		// Working it this way will decrease runtime to something like
		// O(1)
		// Get current threshold ranges
		int thresholdRanges[][] = THRESHOLDS[mRotation];
		int row = -1;
		for (int i = 0; i < thresholdRanges.length; i++) {
		if (orientation >= thresholdRanges[i][0] && orientation < thresholdRanges[i][1]) {
		row = i;
		break;
		boolean transition = false;
		// Check current rotation is ROTATION_0 which only has 3 threshold
		// ranges.
		if (mRotation == ROTATION_0) {
		if(orientation >= thresholdRanges[0][0] && orientation < thresholdRanges[0][1]){
		row = 0;
		} else if(orientation >= thresholdRanges[1][0] && orientation < thresholdRanges[1][1]){
		row = 1;
		} else if(orientation >= thresholdRanges[2][0] && orientation < thresholdRanges[2][1]){
		row = 2;
		}
		// Check the other rotation threshold ranges. Set row accordingly.
		}else{
		if(orientation >= thresholdRanges[0][0] && orientation < thresholdRanges[0][1]){
		row = 0;
		} else if(orientation >= thresholdRanges[1][0] && orientation < thresholdRanges[1][1]){
		row = 1;
		} else if(orientation >= thresholdRanges[2][0] && orientation < thresholdRanges[2][1]){
		row = 2;
		} else if(orientation >= thresholdRanges[3][0] && orientation < thresholdRanges[3][1]){
		row = 3;
		}
		}
		return row;
		}
		}
		if (row == -1) return; // no matching transition

		private void calculateNewRotation(int orientation, int tiltAngle) {
		if (localLOGV) Log.i(TAG, orientation + ", " + tiltAngle + ", " + mRotation);

		int row = testThreshold(orientation);
		if (row == -1) return;

		int rotation = ROTATE_TO[mRotation][row];

		if (tiltAngle > MAX_TRANSITION_TILT[rotation]) {
		// tilted too far flat to go to this rotation
		return;
		@@ -291,6 +338,7 @@ public abstract class WindowOrientationListener {
		break;
		}
		}

		if (!allowed) {
		if (localLOGV) Log.i(TAG, " not allowed rotation = " + rotation);
		return;