private void setChildOffsetsHorizontal(@Gravity int gravity,
                                           @Dimension int radius,
                                           Point center,
                                           int peekDistance) {
        for (int i = 0; i < getChildCount(); i++) {
            View child = getChildAt(i);
            if (child == null) continue;
            RecyclerView.LayoutParams layoutParams = (RecyclerView.LayoutParams) child.getLayoutParams();
            final int yOffset = (int) resolveOffsetY(radius, child.getX() + child.getWidth() / 2.0f, center, peekDistance);
            final int y = gravity == Gravity.START ? yOffset + getMarginStart(layoutParams)
                    : getHeight() - yOffset - child.getHeight() - getMarginStart(layoutParams);

            child.layout(child.getLeft(), y, child.getRight(), child.getHeight() + y);
            setChildRotationHorizontal(gravity, child, radius, center);
        }
    }
Set bumper offsets on child views for {@link Orientation#HORIZONTAL}
turn/src/main/java/cdflynn/android/library/turn/TurnLayoutManager.java