private void translateImageToCenterTouchPosition(float t) {
            float targetX = startTouch.x + t * (endTouch.x - startTouch.x);
            float targetY = startTouch.y + t * (endTouch.y - startTouch.y);
            PointF curr = transformCoordBitmapToTouch(bitmapX, bitmapY);
            matrix.postTranslate(targetX - curr.x, targetY - curr.y);
        }
Interpolate between where the image should start and end in order to translate
the image so that the point that is touched is what ends up centered at the end
of the zoom.

@param t
app/src/main/java/home/smart/fly/animations/customview/gallery/TouchImageView.java