1 /* 2 * Copyright (C) 2024 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.server.vibrator; 18 19 import android.hardware.vibrator.IVibrator; 20 import android.os.VibratorInfo; 21 import android.os.vibrator.Flags; 22 import android.os.vibrator.PwleSegment; 23 import android.os.vibrator.VibrationEffectSegment; 24 import android.util.MathUtils; 25 26 import java.util.ArrayList; 27 import java.util.List; 28 29 /** 30 * Adapter that splits Pwle segments with longer duration than the device capabilities. 31 * 32 * <p>This transformation replaces large {@link android.os.vibrator.PwleSegment} entries by a 33 * sequence of smaller segments that starts and ends at the same amplitudes/frequencies, 34 * interpolating the intermediate values. 35 * 36 * <p>The segments will not be changed if the device doesn't have 37 * {@link IVibrator#CAP_COMPOSE_PWLE_EFFECTS_V2}. 38 */ 39 final class SplitPwleSegmentsAdapter implements VibrationSegmentsAdapter { 40 41 @Override adaptToVibrator(VibratorInfo info, List<VibrationEffectSegment> segments, int repeatIndex)42 public int adaptToVibrator(VibratorInfo info, List<VibrationEffectSegment> segments, 43 int repeatIndex) { 44 if (!Flags.normalizedPwleEffects() 45 || !info.hasCapability(IVibrator.CAP_COMPOSE_PWLE_EFFECTS_V2)) { 46 // The vibrator does not have PWLE v2 capability, so keep the segments unchanged. 47 return repeatIndex; 48 } 49 int maxPwleDuration = (int) info.getMaxEnvelopeEffectDurationMillis(); 50 if (maxPwleDuration <= 0) { 51 // No limit set to PWLE primitive duration. 52 return repeatIndex; 53 } 54 55 int segmentCount = segments.size(); 56 for (int i = 0; i < segmentCount; i++) { 57 if (!(segments.get(i) instanceof PwleSegment pwleSegment)) { 58 continue; 59 } 60 int splits = ((int) pwleSegment.getDuration() + maxPwleDuration - 1) / maxPwleDuration; 61 if (splits <= 1) { 62 continue; 63 } 64 segments.remove(i); 65 segments.addAll(i, splitPwleSegment(pwleSegment, splits)); 66 int addedSegments = splits - 1; 67 if (repeatIndex > i) { 68 repeatIndex += addedSegments; 69 } 70 i += addedSegments; 71 segmentCount += addedSegments; 72 } 73 74 return repeatIndex; 75 } 76 splitPwleSegment(PwleSegment pwleSegment, int splits)77 private static List<PwleSegment> splitPwleSegment(PwleSegment pwleSegment, 78 int splits) { 79 List<PwleSegment> pwleSegments = new ArrayList<>(splits); 80 float startFrequencyHz = pwleSegment.getStartFrequencyHz(); 81 float endFrequencyHz = pwleSegment.getEndFrequencyHz(); 82 long splitDuration = pwleSegment.getDuration() / splits; 83 float previousAmplitude = pwleSegment.getStartAmplitude(); 84 float previousFrequencyHz = startFrequencyHz; 85 long accumulatedDuration = 0; 86 87 for (int i = 1; i < splits; i++) { 88 accumulatedDuration += splitDuration; 89 float durationRatio = (float) accumulatedDuration / pwleSegment.getDuration(); 90 float interpolatedFrequency = 91 MathUtils.lerp(startFrequencyHz, endFrequencyHz, durationRatio); 92 float interpolatedAmplitude = MathUtils.lerp(pwleSegment.getStartAmplitude(), 93 pwleSegment.getEndAmplitude(), durationRatio); 94 PwleSegment pwleSplit = new PwleSegment( 95 previousAmplitude, interpolatedAmplitude, 96 previousFrequencyHz, interpolatedFrequency, 97 (int) splitDuration); 98 pwleSegments.add(pwleSplit); 99 previousAmplitude = pwleSplit.getEndAmplitude(); 100 previousFrequencyHz = pwleSplit.getEndFrequencyHz(); 101 } 102 103 pwleSegments.add( 104 new PwleSegment(previousAmplitude, pwleSegment.getEndAmplitude(), 105 previousFrequencyHz, endFrequencyHz, 106 (int) (pwleSegment.getDuration() - accumulatedDuration))); 107 108 return pwleSegments; 109 } 110 } 111