float[] projectCoord(float[] coord, CameraCalibration cameraCalibration, Matrix34F pose, float[] offset, float scale)
{
    float[] converted = new float[2];

    Vec3F vec = new Vec3F(coord[0], coord[1], 0);
    Vec2F sc = Tool.projectPoint(cameraCalibration, pose, vec);
    converted[0] = sc.getData()[0]*scale - offset[0];
    converted[1] = sc.getData()[1]*scale - offset[1];

    return converted;
}

void calcScreenCoordsOf(float[] target, Matrix34F pose)
{
    // 0,0 is at centre of target so extremities are at w/2,h/2
    float w = target[0];
    float h = target[1];

    // need to account for the orientation on view size
    DisplayMetrics metrics = new DisplayMetrics();
    mActivity.getWindowManager().getDefaultDisplay().getMetrics(metrics);
    float viewHeight = metrics.widthPixels; // Portrait
    float viewWidth = metrics.heightPixels - getStatusBarHeight(); // Portrait

    // calculate any mismatch of screen to video size
    CameraDevice cameraDevice = CameraDevice.getInstance();
    CameraCalibration cameraCalibration = cameraDevice.getCameraCalibration();
    VideoMode videoMode = cameraDevice.getVideoMode(CameraDevice.MODE.MODE_DEFAULT);

    float scale = viewWidth/videoMode.getWidth();
    if (videoMode.getHeight() * scale < viewHeight)
        scale = viewHeight/videoMode.getHeight();
    float scaledWidth = videoMode.getWidth() * scale;
    float scaledHeight = videoMode.getHeight() * scale;

    float[] margin = {(scaledWidth - viewWidth)/2, (scaledHeight - viewHeight)/2};

    // now project the 4 corners of the target
    final float[] x1 = projectCoord(new float[]{-w,h}, cameraCalibration, pose, margin, scale);
    final float[] x2 = projectCoord(new float[]{-w,-h}, cameraCalibration, pose, margin, scale);
    final float[] x3 = projectCoord(new float[]{w,-h}, cameraCalibration, pose, margin, scale);
    final float[] x4 = projectCoord(new float[]{w,h}, cameraCalibration, pose, margin, scale);

    // 4 views
    mActivity.runOnUiThread(new Runnable() {
        @Override
        public void run() {
            RelativeLayout.LayoutParams params1 = new RelativeLayout.LayoutParams(10, 10);
            params1.leftMargin = Math.round(x1[0]);
            params1.topMargin = Math.round(x1[1]);
            mActivity.view1.setLayoutParams(params1);

            RelativeLayout.LayoutParams params2 = new RelativeLayout.LayoutParams(10, 10);
            params2.leftMargin = Math.round(x2[0]);
            params2.topMargin = Math.round(x2[1]);
            mActivity.view2.setLayoutParams(params2);

            RelativeLayout.LayoutParams params3 = new RelativeLayout.LayoutParams(10, 10);
            params3.leftMargin = Math.round(x3[0]);
            params3.topMargin = Math.round(x3[1]);
            mActivity.view3.setLayoutParams(params3);

            RelativeLayout.LayoutParams params4 = new RelativeLayout.LayoutParams(10, 10);
            params4.leftMargin = Math.round(x4[0]);
            params4.topMargin = Math.round(x4[1]);
            mActivity.view4.setLayoutParams(params4);
        }
    });


}