public void print(Graphics g, int x, int lag){
		g.drawImage(bg.getImg(), 0, 0, null);
		int j0 = (x-lag)/genObstacle.sWidth -1;	// part of the grid to draw the obstacles (j0<0 special case)
		int j1 = j0 + Stubi.WINDX/genObstacle.sWidth + 2;
		for (int i = 0; i<obstacles.length;++i){	// i = y coord
			for (int j = j0; j<obstacles[i].length && j<=j1; ++j) { // j = x coord
				Obstacle tmp;
				int xx = lag - x; // Position of printing
					if (j<0) {
						// Print the beginning of the level (a wall ? a repeat of the first sequence ?)
						tmp = obstacles[i][0];
						xx += tmp.getX() + genObstacle.getWidth()*j;
					} else {
						tmp = obstacles[i][j];
						xx += tmp.getX();
					}
					if (tmp.visible()) {
						int y = tmp.getY();
						g.drawImage(tmp.getImg(),xx, y, null);	// Buffered Image, x coord, y coord, no Image observer
					}
			}
		}
	}