1 /*
2  * Copyright (C) 2014 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.ex.camera2.portability;
18 
19 import android.graphics.Matrix;
20 import android.graphics.RectF;
21 
22 import com.android.ex.camera2.portability.debug.Log;
23 
24 /**
25  * The device info for all attached cameras.
26  */
27 public interface CameraDeviceInfo {
28 
29     static final int NO_DEVICE = -1;
30 
31     /**
32      * @param cameraId Which device to interrogate.
33      * @return The static characteristics of the specified device, or {@code null} on error.
34      */
getCharacteristics(int cameraId)35     Characteristics getCharacteristics(int cameraId);
36 
37     /**
38      * @return The total number of the available camera devices.
39      */
getNumberOfCameras()40     int getNumberOfCameras();
41 
42     /**
43      * @return The first (lowest) ID of the back cameras or {@code NO_DEVICE}
44      *         if not available.
45      */
getFirstBackCameraId()46     int getFirstBackCameraId();
47 
48     /**
49      * @return The first (lowest) ID of the front cameras or {@code NO_DEVICE}
50      *         if not available.
51      */
getFirstFrontCameraId()52     int getFirstFrontCameraId();
53 
54     /**
55      * Device characteristics for a single camera.
56      */
57     public abstract class Characteristics {
58         private static final Log.Tag TAG = new Log.Tag("CamDvcInfChar");
59 
60         /**
61          * @return Whether the camera faces the back of the device.
62          */
isFacingBack()63         public abstract boolean isFacingBack();
64 
65         /**
66          * @return Whether the camera faces the device's screen.
67          */
isFacingFront()68         public abstract boolean isFacingFront();
69 
70         /**
71          * @return The camera sensor orientation, or the counterclockwise angle
72          *          from its natural position that the device must be held at
73          *          for the sensor to be right side up (in degrees, always a
74          *          multiple of 90, and between 0 and 270, inclusive).
75          */
getSensorOrientation()76         public abstract int getSensorOrientation();
77 
78         /**
79          * @param currentDisplayOrientation
80          *          The current display orientation, measured counterclockwise
81          *          from to the device's natural orientation (in degrees, always
82          *          a multiple of 90, and between 0 and 270, inclusive).
83          * @return
84          *          The relative preview image orientation, or the clockwise
85          *          rotation angle that must be applied to display preview
86          *          frames in the matching orientation, accounting for implicit
87          *          mirroring, if applicable (in degrees, always a multiple of
88          *          90, and between 0 and 270, inclusive).
89          */
getPreviewOrientation(int currentDisplayOrientation)90         public int getPreviewOrientation(int currentDisplayOrientation) {
91             // Drivers tend to mirror the image during front camera preview.
92             return getRelativeImageOrientation(currentDisplayOrientation, true);
93         }
94 
95         /**
96          * @param currentDisplayOrientation
97          *          The current display orientation, measured counterclockwise
98          *          from to the device's natural orientation (in degrees, always
99          *          a multiple of 90, and between 0 and 270, inclusive).
100          * @return
101          *          The relative capture image orientation, or the clockwise
102          *          rotation angle that must be applied to display these frames
103          *          in the matching orientation (in degrees, always a multiple
104          *          of 90, and between 0 and 270, inclusive).
105          */
getJpegOrientation(int currentDisplayOrientation)106         public int getJpegOrientation(int currentDisplayOrientation) {
107             // Don't mirror during capture!
108             return getRelativeImageOrientation(currentDisplayOrientation, false);
109         }
110 
111         /**
112          * @param currentDisplayOrientaiton
113          *          {@link #getPreviewOrientation}, {@link #getJpegOrientation}
114          * @param compensateForMirroring
115          *          Whether to account for mirroring in the case of front-facing
116          *          cameras, which is necessary iff the OS/driver is
117          *          automatically reflecting the image.
118          * @return
119          *          {@link #getPreviewOrientation}, {@link #getJpegOrientation}
120          *
121          * @see android.hardware.Camera.setDisplayOrientation
122          */
getRelativeImageOrientation(int currentDisplayOrientation, boolean compensateForMirroring)123         protected int getRelativeImageOrientation(int currentDisplayOrientation,
124                                                   boolean compensateForMirroring) {
125             if (!orientationIsValid(currentDisplayOrientation)) {
126                 return 0;
127             }
128 
129             int result = 0;
130             if (isFacingFront()) {
131                 result = (getSensorOrientation() + currentDisplayOrientation) % 360;
132                 if (compensateForMirroring) {
133                     result = (360 - result) % 360;
134                 }
135             } else if (isFacingBack()) {
136                 result = (getSensorOrientation() - currentDisplayOrientation + 360) % 360;
137             } else {
138                 Log.e(TAG, "Camera is facing unhandled direction");
139             }
140             return result;
141         }
142 
143         /**
144          * @param currentDisplayOrientation
145          *          The current display orientation, measured counterclockwise
146          *          from to the device's natural orientation (in degrees, always
147          *          a multiple of 90, and between 0 and 270, inclusive).
148          * @param surfaceDimensions
149          *          The dimensions of the {@link android.view.Surface} on which
150          *          the preview image is being rendered. It usually only makes
151          *          sense for the upper-left corner to be at the origin.
152          * @return
153          *          The transform matrix that should be applied to the
154          *          {@link android.view.Surface} in order for the image to
155          *          display properly in the device's current orientation.
156          */
getPreviewTransform(int currentDisplayOrientation, RectF surfaceDimensions)157         public Matrix getPreviewTransform(int currentDisplayOrientation, RectF surfaceDimensions) {
158             return getPreviewTransform(currentDisplayOrientation, surfaceDimensions,
159                     new RectF(surfaceDimensions));
160         }
161 
162         /**
163          * @param currentDisplayOrientation
164          *          The current display orientation, measured counterclockwise
165          *          from to the device's natural orientation (in degrees, always
166          *          a multiple of 90, and between 0 and 270, inclusive).
167          * @param surfaceDimensions
168          *          The dimensions of the {@link android.view.Surface} on which
169          *          the preview image is being rendered. It usually only makes
170          *          sense for the upper-left corner to be at the origin.
171          * @param desiredBounds
172          *          The boundaries within the {@link android.view.Surface} where
173          *          the final image should appear. These can be used to
174          *          translate and scale the output, but note that the image will
175          *          be stretched to fit, possibly changing its aspect ratio.
176          * @return
177          *          The transform matrix that should be applied to the
178          *          {@link android.view.Surface} in order for the image to
179          *          display properly in the device's current orientation.
180          */
getPreviewTransform(int currentDisplayOrientation, RectF surfaceDimensions, RectF desiredBounds)181         public Matrix getPreviewTransform(int currentDisplayOrientation, RectF surfaceDimensions,
182                                           RectF desiredBounds) {
183             if (!orientationIsValid(currentDisplayOrientation) ||
184                     surfaceDimensions.equals(desiredBounds)) {
185                 return new Matrix();
186             }
187 
188             Matrix transform = new Matrix();
189             transform.setRectToRect(surfaceDimensions, desiredBounds, Matrix.ScaleToFit.FILL);
190             return transform;
191         }
192 
193         /**
194          * @return Whether the shutter sound can be disabled.
195          */
canDisableShutterSound()196         public abstract boolean canDisableShutterSound();
197 
orientationIsValid(int angle)198         protected static boolean orientationIsValid(int angle) {
199             if (angle % 90 != 0) {
200                 Log.e(TAG, "Provided display orientation is not divisible by 90");
201                 return false;
202             }
203             if (angle < 0 || angle > 270) {
204                 Log.e(TAG, "Provided display orientation is outside expected range");
205                 return false;
206             }
207             return true;
208         }
209     }
210 }
211