如何使用raphael.js绘制带有每个角落控制点的多边形形状。
控制点应该是可拖动的,当控制点移动时,相关的线条也应该移动。有什么想法吗?
如何使用raphael.js绘制带有每个角落控制点的多边形形状。
控制点应该是可拖动的,当控制点移动时,相关的线条也应该移动。有什么想法吗?
// Creates canvas
var paper = Raphael("canvas1", "100%", "100%");
// create small circle for each polygon point
var p1 = paper.circle(150, 50, 5).attr("fill", "blue");
var p2 = paper.circle(200, 100, 5).attr("fill", "blue");
var p3 = paper.circle(200, 200, 5).attr("fill", "blue");
var p4 = paper.circle(100, 200, 5).attr("fill", "blue");
var p5 = paper.circle(100, 100, 5).attr("fill", "blue");
接下来,我们需要以一种方式连接控制点,使得线条在更新后能够自动重绘。在这个问题中有一个方便的函数可以实现此功能,我稍作修改以适应我们的需求(它现在监听drag
事件,将线条属性作为参数接受,并修复了我在原问题评论中指出的一个错误):
// Modified from: https://dev59.com/nGLVa4cB1Zd3GeqPty2O
// Call paper.connect(obj1,obj2,attributes)
// That draws a line between the two objects and maintains the line when the objects are animated
Raphael.fn.connect = function(obj1, obj2, attribs) {
// list of paths each object has
if (!obj1.connections) obj1.connections = []
if (!obj2.connections) obj2.connections = []
// get the bounding box of each object
var box1 = obj1.getBBox()
var box2 = obj2.getBBox()
// create a line/path from object 1 to object 2
var p = this.path("M" + (box1.x + box1.width / 2) + ","
+ (box1.y + box1.height / 2) + "L" + (box2.x + box2.width / 2)
+ "," + (box2.y + box2.height / 2))
// adjust attributes of the path
p.attr(attribs)
// set the start and end element for this path
p.startElement = obj1;
p.endElement = obj2;
// add the path to each of the object
obj1.connections.push(p)
obj2.connections.push(p)
// mark each object as being connected
obj1.connected = true;
obj2.connected = true;
// listen for the Raphael frame event
eve.on("raphael.drag.*", function(obj) {
// if the object the frame event is fired on is connected
if (this.connected) {
// for each connection on this object
for ( var c in this.connections) {
var path = this.connections[c]; // temp path
var b1 = path.startElement.getBBox(); // get the current
// location of start
// element
var b2 = path.endElement.getBBox();// get the current location
// of end element
// move the path to the new locations
path.attr({
path : "M " + (b1.x + b1.width / 2) + " "
+ (b1.y + b1.height / 2) + "L "
+ (b2.x + b2.width / 2) + " "
+ (b2.y + b2.height / 2),
opacity : Math.max(path.startElement.attr('opacity'),
path.endElement.attr('opacity'))
});
}
}
});
}
// connect adjacent polygon points
paper.connect(p1,p2,{stroke:"red"});
paper.connect(p2,p3,{stroke:"red"});
paper.connect(p3,p4,{stroke:"red"});
paper.connect(p4,p5,{stroke:"red"});
paper.connect(p5,p1,{stroke:"red"});
// make points draggable
var start = function () {
this.ox = this.attr("cx");
this.oy = this.attr("cy");
},
move = function (dx, dy) {
this.attr({cx: this.ox + dx, cy: this.oy + dy});
},
up = function () {};
paper.set(p1,p2,p3,p4,p5).drag(move, start, up);