https://blog.csdn.net/sandalphon4869/article/details/89341443
https://blog.csdn.net/swinfans/article/details/89393853
https://zhuanlan.zhihu.com/p/614018391
https://blog.csdn.net/qq_42491125/article/details/114005171
https://www.cnblogs.com/leween/p/12945751.html#_label4

方向

TB = TD - top bottom -从上到下
BT - bottom top - 从下到上
LR - left right - 自左向右
RL - right left - 自右向左

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节点样式

https://blog.csdn.net/sandalphon4869/article/details/89341443

形状

矩形 [内容]
圆角矩形 (内容)
圆形 ((内容))
菱形 {内容}
旗帜 >内容]

箭头

子图

流程图

http://flowchart.js.org/

类图

uml图

甘特图