snippets/sector.js

28 lines
946 B
JavaScript

function getSectorPath(centre, rIn, rOut, startDeg, delta) {
const startOut = {
x: centre.x + rOut * Math.cos(startDeg),
y: centre.y + rOut * Math.sin(startDeg)
};
const endOut = {
x: centre.x + rOut * Math.cos(startDeg + delta),
y: centre.y + rOut * Math.sin(startDeg + delta)
};
const startIn = {
x: centre.x + rIn * Math.cos(startDeg + delta),
y: centre.y + rIn * Math.sin(startDeg + delta)
};
const endIn = {
x: centre.x + rIn * Math.cos(startDeg),
y: centre.y + rIn * Math.sin(startDeg)
};
const largeArc = delta > 180 ? 1 : 0;
return [
`M${startOut.x},${startOut.y}`, `A${rOut},${rOut}`, '0',
`${largeArc},1`, `${endOut.x},${endOut.y}`,
`L${startIn.x},${startIn.y}`,
`A${rIn},${rIn}`, '0', `${largeArc},0`,
`${endIn.x},${endIn.y}`,
`L${startOut.x},${startOut.y}`, 'Z',
].join(' ');
}