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 #include "ModeSelector.h"
18
19 namespace android {
20 namespace media {
21
ModeSelector(const Options & options,HeadTrackingMode initialMode)22 ModeSelector::ModeSelector(const Options& options, HeadTrackingMode initialMode)
23 : mOptions(options), mDesiredMode(initialMode), mActualMode(initialMode) {}
24
setDesiredMode(HeadTrackingMode mode)25 void ModeSelector::setDesiredMode(HeadTrackingMode mode) {
26 mDesiredMode = mode;
27 }
28
setScreenToStagePose(const Pose3f & screenToStage)29 void ModeSelector::setScreenToStagePose(const Pose3f& screenToStage) {
30 mScreenToStage = screenToStage;
31 }
32
setScreenToHeadPose(int64_t timestamp,const std::optional<Pose3f> & screenToHead)33 void ModeSelector::setScreenToHeadPose(int64_t timestamp,
34 const std::optional<Pose3f>& screenToHead) {
35 mScreenToHead = screenToHead;
36 mScreenToHeadTimestamp = timestamp;
37 }
38
setWorldToHeadPose(int64_t timestamp,const Pose3f & worldToHead)39 void ModeSelector::setWorldToHeadPose(int64_t timestamp, const Pose3f& worldToHead) {
40 mWorldToHead = worldToHead;
41 mWorldToHeadTimestamp = timestamp;
42 }
43
calculateActualMode(int64_t timestamp)44 void ModeSelector::calculateActualMode(int64_t timestamp) {
45 bool isValidScreenToHead = mScreenToHead.has_value() &&
46 timestamp - mScreenToHeadTimestamp < mOptions.freshnessTimeout;
47 bool isValidWorldToHead = mWorldToHead.has_value() &&
48 timestamp - mWorldToHeadTimestamp < mOptions.freshnessTimeout;
49
50 HeadTrackingMode mode = mDesiredMode;
51
52 // Optional downgrade from screen-relative to world-relative.
53 if (mode == HeadTrackingMode::SCREEN_RELATIVE) {
54 if (!isValidScreenToHead) {
55 mode = HeadTrackingMode::WORLD_RELATIVE;
56 }
57 }
58
59 // Optional downgrade from world-relative to static.
60 if (mode == HeadTrackingMode::WORLD_RELATIVE) {
61 if (!isValidWorldToHead) {
62 mode = HeadTrackingMode::STATIC;
63 }
64 }
65
66 mActualMode = mode;
67 }
68
calculate(int64_t timestamp)69 void ModeSelector::calculate(int64_t timestamp) {
70 calculateActualMode(timestamp);
71
72 switch (mActualMode) {
73 case HeadTrackingMode::STATIC:
74 mHeadToStage = mScreenToStage;
75 break;
76
77 case HeadTrackingMode::WORLD_RELATIVE:
78 mHeadToStage = mWorldToHead.value().inverse() * mScreenToStage;
79 break;
80
81 case HeadTrackingMode::SCREEN_RELATIVE:
82 mHeadToStage = mScreenToHead.value().inverse() * mScreenToStage;
83 break;
84 }
85 }
86
getHeadToStagePose() const87 Pose3f ModeSelector::getHeadToStagePose() const {
88 return mHeadToStage;
89 }
90
getActualMode() const91 HeadTrackingMode ModeSelector::getActualMode() const {
92 return mActualMode;
93 }
94
95 } // namespace media
96 } // namespace android
97