问题
I am studing paper.js and don´t found how resolve my problem. See my application test in: http://www.plugbox.com.br/reta.htm
The red circle covers only the Y axis and blue circle covers only the X axis and the starting point and the end point of the line follow the red and blue points.
But the line is in front of circles. How do I set the "z-index" line by placing it in a layer behind the points?
Another question is:
How do I put a third point, for example, in the middle of the line and make it draggable only on the line?
Thank´s!
回答1:
But the line is in front of circles. How do I set the "z-index" line by placing it in a layer behind the points?
Every item has methods:
insertAbove(item) //Inserts this item above the specified item.
insertBelow(item) //Inserts this item below the specified item.
sendToBack() //Sends this item to the back of all other items within the same parent.
source
回答2:
It's easy. Draw the line first and the dots afterward.Just with a real-life painting: what you draw last is atop everything you have drawn first. Plain SVG behaves the same btw.
来源：https://stackoverflow.com/questions/25691561/paper-js-z-index-and-binding-object