1 /*
2  * Copyright (C) 2021 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.os.VibratorInfo;
20 import android.os.vibrator.RampSegment;
21 import android.os.vibrator.VibrationEffectSegment;
22 import android.util.MathUtils;
23 import android.util.Range;
24 
25 import java.util.List;
26 
27 /**
28  * Adapter that clips frequency values to the supported range specified by
29  * {@link VibratorInfo.FrequencyProfile}, then clips amplitude values to the max supported one at
30  * each frequency.
31  *
32  * <p>The {@link VibratorInfo.FrequencyProfile} is only applicable to PWLE compositions. This
33  * adapter is only applied to {@link RampSegment} and all other segments will remain unchanged.
34  */
35 final class ClippingAmplitudeAndFrequencyAdapter implements VibrationSegmentsAdapter {
36 
37     @Override
adaptToVibrator(VibratorInfo info, List<VibrationEffectSegment> segments, int repeatIndex)38     public int adaptToVibrator(VibratorInfo info, List<VibrationEffectSegment> segments,
39             int repeatIndex) {
40         int segmentCount = segments.size();
41         for (int i = 0; i < segmentCount; i++) {
42             VibrationEffectSegment segment = segments.get(i);
43             if (segment instanceof RampSegment) {
44                 segments.set(i, adaptToVibrator(info, (RampSegment) segment));
45             }
46         }
47         return repeatIndex;
48     }
49 
adaptToVibrator(VibratorInfo info, RampSegment segment)50     private RampSegment adaptToVibrator(VibratorInfo info, RampSegment segment) {
51         float clampedStartFrequency = clampFrequency(info, segment.getStartFrequencyHz());
52         float clampedEndFrequency = clampFrequency(info, segment.getEndFrequencyHz());
53         return new RampSegment(
54                 clampAmplitude(info, clampedStartFrequency, segment.getStartAmplitude()),
55                 clampAmplitude(info, clampedEndFrequency, segment.getEndAmplitude()),
56                 clampedStartFrequency,
57                 clampedEndFrequency,
58                 (int) segment.getDuration());
59     }
60 
clampFrequency(VibratorInfo info, float frequencyHz)61     private float clampFrequency(VibratorInfo info, float frequencyHz) {
62         Range<Float> frequencyRangeHz = info.getFrequencyProfile().getFrequencyRangeHz();
63         if (frequencyHz == 0 || frequencyRangeHz == null)  {
64             return Float.isNaN(info.getResonantFrequencyHz()) ? 0 : info.getResonantFrequencyHz();
65         }
66         return frequencyRangeHz.clamp(frequencyHz);
67     }
68 
clampAmplitude(VibratorInfo info, float frequencyHz, float amplitude)69     private float clampAmplitude(VibratorInfo info, float frequencyHz, float amplitude) {
70         VibratorInfo.FrequencyProfile mapping = info.getFrequencyProfile();
71         if (mapping.isEmpty()) {
72             // No frequency mapping was specified so leave amplitude unchanged.
73             // The frequency will be clamped to the device's resonant frequency.
74             return amplitude;
75         }
76         return MathUtils.min(amplitude, mapping.getMaxAmplitude(frequencyHz));
77     }
78 }
79