case DIRECTION_Y:
                if (oldTileX != newTileX) {
                    if (this._isSurface(scene, newTileX, oldTileY)) {
                        pos.tileX = newTileX;
                        pos.tileY = oldTileY;
                        pos.sceneX = Math.floor(startPosX / WALL_SIZE) * WALL_SIZE;
                        if (xDifference >= 0) {
                            pos.sceneX += WALL_SIZE;
                            pos.side = SIDE_LEFT;
                        }
                        else {
                            pos.side = SIDE_RIGHT;
                        }
                        pos.sceneY = this._getEndPosA(controlSizeY, controlSizeX, this._raySourcePosition.y, this._raySourcePosition.x, pos.sceneX);
                        surfaceEarned = true;
                    }
                }
                else {
                    if (this._isSurface(scene, newTileX, newTileY)) {
                        pos.tileX = newTileX;
                        pos.tileY = newTileY;
                        pos.sceneX = endPosX;
                        pos.sceneY = endPosY;
                        pos.side = yDifference >= 0 ? SIDE_UP : SIDE_DOWN;
                        surfaceEarned = true;
                    }
                }
                break;
            default:
                return undefined;
        }//*/
        return (surfaceEarned ? pos : undefined);
    }