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javaandroidcameragoogle-cardboard

How to show 2 camera preview side by side?[For cardboard apps]

I am trying to build a Cardboard android application that shows 2 camera view side by side. [Just like the camera view works for VRCinema Android app.]

VRCinema screen capture

So I studies the Cardboard code from GitHub, made some modification and so far I am able to use the imageView to replicate the same image side by side.

imageView to replicate the same image side by side

and the Code so far looks like this.

AndroidManifest.XML

    <?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
          package="com.google.vrtoolkit.cardboard.samples.treasurehunt" >

    <uses-permission android:name="android.permission.NFC" />
    <uses-permission android:name="android.permission.VIBRATE" />
    <uses-permission android:name="android.permission.CAMERA" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-feature android:name="android.hardware.camera" android:required="false" />
    <uses-feature android:name="android.hardware.camera.autofocus" android:required="false" />
    <uses-feature android:name="android.hardware.camera.front" android:required="false" />


    <uses-sdk android:minSdkVersion="14"/>
    <uses-feature android:glEsVersion="0x00020000" android:required="true" />

    <application
            android:allowBackup="true"
            android:icon="@drawable/ic_launcher"
            android:label="@string/app_name" >

        <activity
                android:screenOrientation="landscape"
                android:name=".MainActivity"
                android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

common_ui.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/ui_layout"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >


    <com.google.vrtoolkit.cardboard.CardboardView
        android:id="@+id/cardboard_view"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_alignParentTop="true"
        android:layout_alignParentLeft="true" />

    <com.google.vrtoolkit.cardboard.samples.treasurehunt.CardboardOverlayView
        android:id="@+id/overlay"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_centerInParent="true" />



</RelativeLayout>

CardboardOverlayView.java

package com.google.vrtoolkit.cardboard.samples.treasurehunt;

        import android.content.Context;
        import android.graphics.Color;
        import android.graphics.Typeface;
        import android.util.AttributeSet;
        import android.util.TypedValue;
        import android.view.Gravity;
        import android.view.View;
        import android.view.ViewGroup;
        import android.view.animation.AlphaAnimation;
        import android.view.animation.Animation;
        import android.widget.ImageView;
        import android.widget.LinearLayout;
        import android.widget.TextView;

/**
 * Contains two sub-views to provide a simple stereo HUD.
 */
public class CardboardOverlayView extends LinearLayout {
    private static final String TAG = CardboardOverlayView_bkp1.class.getSimpleName();
    private final CardboardOverlayEyeView mLeftView;
    private final CardboardOverlayEyeView mRightView;
    private AlphaAnimation mTextFadeAnimation;

    public CardboardOverlayView(Context context, AttributeSet attrs) {
        super(context, attrs);
        setOrientation(HORIZONTAL);

        LayoutParams params = new LayoutParams(
                LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT, 1.0f);
        params.setMargins(0, 0, 0, 0);

        mLeftView = new CardboardOverlayEyeView(context, attrs);
        mLeftView.setLayoutParams(params);
        addView(mLeftView);

        mRightView = new CardboardOverlayEyeView(context, attrs);
        mRightView.setLayoutParams(params);
        addView(mRightView);

        // Set some reasonable defaults.
        setDepthOffset(0.016f);
        setColor(Color.rgb(150, 255, 180));
        setVisibility(View.VISIBLE);

        mTextFadeAnimation = new AlphaAnimation(1.0f, 0.0f);
        mTextFadeAnimation.setDuration(5000);
    }

    public void show3DToast(String message) {
        setText(message);
        setTextAlpha(1f);
        mTextFadeAnimation.setAnimationListener(new EndAnimationListener() {
            @Override
            public void onAnimationEnd(Animation animation) {
                setTextAlpha(0f);
            }
        });
        startAnimation(mTextFadeAnimation);
    }

    public void show3DImage() {
        setImg();

    }

    private abstract class EndAnimationListener implements Animation.AnimationListener {
        @Override public void onAnimationRepeat(Animation animation) {}
        @Override public void onAnimationStart(Animation animation) {}
    }

    private void setDepthOffset(float offset) {
        mLeftView.setOffset(offset);
        mRightView.setOffset(-offset);
    }


    //---------------------------------------------------------------------------------------------
    private void setImg(){
        mLeftView.imageView.setImageResource(R.drawable.mona_lisa);
        mRightView.imageView.setImageResource(R.drawable.mona_lisa);

    }
    //------------------------------------------------------------------------------------------

    private void setText(String text) {
        mLeftView.setText(text);
        mRightView.setText(text);
    }

    private void setTextAlpha(float alpha) {
        mLeftView.setTextViewAlpha(alpha);
        mRightView.setTextViewAlpha(alpha);
    }

    private void setColor(int color) {
        mLeftView.setColor(color);
        mRightView.setColor(color);
    }

    /**
     * A simple view group containing some horizontally centered text underneath a horizontally
     * centered image.
     *
     * This is a helper class for CardboardOverlayView.
     */
    private class CardboardOverlayEyeView extends ViewGroup {
        private final ImageView imageView;
        private final TextView textView;
        private float offset;

        public CardboardOverlayEyeView(Context context, AttributeSet attrs) {
            super(context, attrs);
            imageView = new ImageView(context, attrs);
            imageView.setScaleType(ImageView.ScaleType.FIT_CENTER);
            imageView.setAdjustViewBounds(true);  // Preserve aspect ratio.
            addView(imageView);

            textView = new TextView(context, attrs);
            textView.setTextSize(TypedValue.COMPLEX_UNIT_DIP, 14.0f);
            textView.setTypeface(textView.getTypeface(), Typeface.BOLD);
            textView.setGravity(Gravity.CENTER);
            textView.setShadowLayer(3.0f, 0.0f, 0.0f, Color.DKGRAY);
            addView(textView);
        }

        public void setColor(int color) {
            //imageView.setColorFilter(color);
            textView.setTextColor(color);
        }

        public void setText(String text) {
            textView.setText(text);
        }

        public void setTextViewAlpha(float alpha) {
            textView.setAlpha(alpha);
        }

        public void setOffset(float offset) {
            this.offset = offset;
        }

        @Override
        protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
            // Width and height of this ViewGroup.
            final int width = right - left;
            final int height = bottom - top;

            // The size of the image, given as a fraction of the dimension as a ViewGroup. We multiply
            // both width and heading with this number to compute the image's bounding box. Inside the
            // box, the image is the horizontally and vertically centered.
            final float imageSize = 1.0f;

            // The fraction of this ViewGroup's height by which we shift the image off the ViewGroup's
            // center. Positive values shift downwards, negative values shift upwards.
            final float verticalImageOffset = -0.07f;

            // Vertical position of the text, specified in fractions of this ViewGroup's height.
            final float verticalTextPos = 0.52f;

            // Layout ImageView
            float imageMargin = (1.0f - imageSize) / 2.0f;
            float leftMargin = (int) (width * (imageMargin + offset));
            float topMargin = (int) (height * (imageMargin + verticalImageOffset));
            imageView.layout(
                    (int) leftMargin, (int) topMargin,
                    (int) (leftMargin + width * imageSize), (int) (topMargin + height * imageSize));

            // Layout TextView
            leftMargin = offset * width;
            topMargin = height * verticalTextPos;
            textView.layout(
                    (int) leftMargin, (int) topMargin,
                    (int) (leftMargin + width), (int) (topMargin + height * (1.0f - verticalTextPos)));
        }
    }
}

MainActivity.Java

package com.google.vrtoolkit.cardboard.samples.treasurehunt;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.hardware.Camera;
import android.net.Uri;
import android.os.Bundle;
import android.os.Vibrator;
import android.util.Log;
import android.widget.ImageView;
import com.google.vrtoolkit.cardboard.*;
import javax.microedition.khronos.egl.EGLConfig;
import java.nio.FloatBuffer;

/**
 * A Cardboard sample application.
 */
public class MainActivity extends CardboardActivity implements CardboardView.StereoRenderer {


    private static final int CAMERA_REQUEST = 1888;

    private static final String TAG = "MainActivity";
    private static final int CAPTURE_IMAGE_ACTIVITY_REQ = 0;

    Uri fileUri = null;
    ImageView photoImage = null;

    private static final float CAMERA_Z = 0.01f;
    private static final float TIME_DELTA = 0.3f;

    private static final float YAW_LIMIT = 0.12f;
    private static final float PITCH_LIMIT = 0.12f;

    // We keep the light always position just above the user.
    private final float[] mLightPosInWorldSpace = new float[]{0.0f, 2.0f, 0.0f, 1.0f};
    private final float[] mLightPosInEyeSpace = new float[4];

    private static final int COORDS_PER_VERTEX = 3;

    private final WorldLayoutData DATA = new WorldLayoutData();

    private FloatBuffer mFloorVertices;
    private FloatBuffer mFloorColors;
    private FloatBuffer mFloorNormals;

    private FloatBuffer mCubeVertices;
    private FloatBuffer mCubeColors;
    private FloatBuffer mCubeFoundColors;
    private FloatBuffer mCubeNormals;

    private int mGlProgram;
    private int mPositionParam;
    private int mNormalParam;
    private int mColorParam;
    private int mModelViewProjectionParam;
    private int mLightPosParam;
    private int mModelViewParam;
    private int mModelParam;
    private int mIsFloorParam;

    private float[] mModelCube;
    private float[] mCamera;
    private float[] mView;
    private float[] mHeadView;
    private float[] mModelViewProjection;
    private float[] mModelView;

    private float[] mModelFloor;

    private int mScore = 0;
    private float mObjectDistance = 12f;
    private float mFloorDepth = 20f;

    private Vibrator mVibrator;

    private CardboardOverlayView mOverlayView;

    public MainActivity() {
    }

    /**
     * Sets the view to our CardboardView and initializes the transformation matrices we will use
     * to render our scene.
     * //@param savedInstanceState
     */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.common_ui);
        CardboardView cardboardView = (CardboardView) findViewById(R.id.cardboard_view);
        cardboardView.setRenderer(this);
        setCardboardView(cardboardView);

        mModelCube = new float[16];
        mCamera = new float[16];
        mView = new float[16];
        mModelViewProjection = new float[16];
        mModelView = new float[16];
        mModelFloor = new float[16];
        mHeadView = new float[16];
        mVibrator = (Vibrator) getSystemService(Context.VIBRATOR_SERVICE);


        mOverlayView = (CardboardOverlayView) findViewById(R.id.overlay);
        mOverlayView.show3DToast("Pull the magnet when you find an object.");

        mOverlayView.show3DImage();

    }

    @Override
    public void onRendererShutdown(){Log.i(TAG, "onRendererShutdown");
    }

    @Override
    public void onSurfaceChanged(int width, int height) {
        Log.i(TAG, "onSurfaceChanged");
    }

    /**
     * Creates the buffers we use to store information about the 3D world. OpenGL doesn't use Java
     * arrays, but rather needs data in a format it can understand. Hence we use ByteBuffers.
     *
     * @param config The EGL configuration used when creating the surface.
     */
    @Override
    public void onSurfaceCreated(EGLConfig config) {
        Log.i(TAG, "onSurfaceCreated");
    }

    /**
     * Prepares OpenGL ES before we draw a frame.
     *
     * @param headTransform The head transformation in the new frame.
     */
    @Override
    public void onNewFrame(HeadTransform headTransform) {
    }

    /**
     * Draws a frame for an eye. The transformation for that eye (from the camera) is passed in as
     * a parameter.
     *
     * @param transform The transformations to apply to render this eye.
     */
    @Override
    public void onDrawEye(EyeTransform transform) {
    }

    @Override
    public void onFinishFrame(Viewport viewport) {
    }

}

Points I have noticed:

  • I don't want an intent, I need the camera preview so that later I can do other things with it like taking a picture.
  • If I try to replace the imageView with surfaceView I hit an error "rendering problem class could not be found : CardboardOverlayView.java" in common_ui.xml. But the file is there and it's a known and reported bug.
  • The other way I can think of doing it is capture and save image every second and update 2 image view's with the image. However I'm not sure if that's the right way to do it or how to do it.

I have also checked all the links that are available in stack overflow since last 3 days. The closest to my question was Android multuple camera preview - but it's not quite exactly solves my question. I have also gone through the Android - Camera documentation and learned about how they are using cameraPreview and surfaceView.

So my question is what do I need to do now to be able to see the CameraPreview [or the surfaceView that holds the CameraPreview] instead of the Imageview so that I cam provide live camera feed like a split screen in landscape mode?

I hope the question is detailed enough.Still if you need any further info, just ask.

Solution

  • Basically you need to draw the camera into an OpenGL texture and show the texture.

    I wrote two versions of this here, feel free to modify the code and add pull requests: https://github.com/Sveder/CardboardPassthrough