private void computeLineClear(int linesCleared) {
		assert linesCleared >= 0 && linesCleared <= 4 : linesCleared;
		
		if (linesCleared == 0) {
			combo = 0;
			return;
		}
		
		totalLines += linesCleared;
		
		int lineScore = 0;
		String msg = "";
		switch (linesCleared) {
		case 1:
			lineScore = 100;
			msg = "Single";
			break;
		case 2:
			lineScore = 300;
			msg = "Double";
			break;
		case 3:
			lineScore = 500;
			msg = "Triple";
			break;
		case 4:
			lineScore = 800;
			msg = "Tetris";
			break;
		}
		
		lineScore *= level;
		score += lineScore;
		
		graphicsComponent.addMessage(msg+" +"+lineScore);
		
		checkLevelUp();
		
		if (combo > 0) {
			int comboScore = combo * 50 * getLevel();
			if (combo == 1)
				graphicsComponent.addMessage("Combo +"+comboScore);
			else
				graphicsComponent.addMessage(combo+"x Combo +"+comboScore);
		}
		
		combo++;
	}