I have a project I am working on that requires me to make a circular navigation with buttons that look like the bars around the Iron Man thing pictured below. I can draw simple
First I'm creating one segment (path). Then I'm reusing it with use rotating it.
const SVG_NS = 'http://www.w3.org/2000/svg';
const SVG_XLINK = "http://www.w3.org/1999/xlink";
const deg = 180 / Math.PI;
let R = 50;// the outer radius
let r = 35;// the inner radius
let A = 2*Math.PI/7;// the angle for the segment + space
let a = 2*A/3; // the angle for the segment
let path = document.createElementNS(SVG_NS, 'path');
let p1 = {x:0,y:-R}
let p2 = {
x : R*Math.cos(a - Math.PI/2),
y : R*Math.sin(a - Math.PI/2)
}
let p3 = {
x : r*Math.cos(a - Math.PI/2),
y : r*Math.sin(a - Math.PI/2)
}
let p4 = {
x : 0,
y : -r
}
let d = `M${p1.x},${p1.y}
A${R},${R} 0 0,1,${p2.x},${p2.y}
L${p3.x},${p3.y}
A${r},${r} 0 0,0,${p4.x},${p4.y}
L${p1.x},${p1.y}Z
`;
path.setAttributeNS(null, "d", d);
path.setAttributeNS(null, "id", "arc");
defs.appendChild(path);
for(let i = 0; i < 7; i++){
let use = document.createElementNS(SVG_NS, 'use');
use.setAttributeNS(SVG_XLINK, "xlink:href", "#arc")
use.setAttributeNS(null, "fill", "gold");
use.setAttributeNS(null, "transform", `rotate(${i*A*deg})`);
svg.appendChild(use);
}
Or even simpler: this time I'm using stroke-dasharray
and I'm calculating the size for the stroke and the gaps
const SVG_NS = 'http://www.w3.org/2000/svg';
let R = 40;
let perimeter = 2*Math.PI*R
let dash = .7*perimeter/7;
let gap = .3*perimeter/7;
let dasharray = document.createElementNS(SVG_NS, 'circle');
dasharray.setAttributeNS(null, "r", R);
dasharray.setAttributeNS(null, "stroke-dasharray", `${dash}, ${gap}`);
svg.appendChild(dasharray);
circle{stroke-width:20px; stroke:black;fill:none;}