in Hands-on lab/lab-files/starter-project/NorthwindMVC/wwwroot/lib/Chart.js/chart.js [1241:1342]
function drawPoint(ctx, options, x, y) {
let type, xOffset, yOffset, size, cornerRadius;
const style = options.pointStyle;
const rotation = options.rotation;
const radius = options.radius;
let rad = (rotation || 0) * RAD_PER_DEG;
if (style && typeof style === 'object') {
type = style.toString();
if (type === '[object HTMLImageElement]' || type === '[object HTMLCanvasElement]') {
ctx.save();
ctx.translate(x, y);
ctx.rotate(rad);
ctx.drawImage(style, -style.width / 2, -style.height / 2, style.width, style.height);
ctx.restore();
return;
}
}
if (isNaN(radius) || radius <= 0) {
return;
}
ctx.beginPath();
switch (style) {
default:
ctx.arc(x, y, radius, 0, TAU);
ctx.closePath();
break;
case 'triangle':
ctx.moveTo(x + Math.sin(rad) * radius, y - Math.cos(rad) * radius);
rad += TWO_THIRDS_PI;
ctx.lineTo(x + Math.sin(rad) * radius, y - Math.cos(rad) * radius);
rad += TWO_THIRDS_PI;
ctx.lineTo(x + Math.sin(rad) * radius, y - Math.cos(rad) * radius);
ctx.closePath();
break;
case 'rectRounded':
cornerRadius = radius * 0.516;
size = radius - cornerRadius;
xOffset = Math.cos(rad + QUARTER_PI) * size;
yOffset = Math.sin(rad + QUARTER_PI) * size;
ctx.arc(x - xOffset, y - yOffset, cornerRadius, rad - PI, rad - HALF_PI);
ctx.arc(x + yOffset, y - xOffset, cornerRadius, rad - HALF_PI, rad);
ctx.arc(x + xOffset, y + yOffset, cornerRadius, rad, rad + HALF_PI);
ctx.arc(x - yOffset, y + xOffset, cornerRadius, rad + HALF_PI, rad + PI);
ctx.closePath();
break;
case 'rect':
if (!rotation) {
size = Math.SQRT1_2 * radius;
ctx.rect(x - size, y - size, 2 * size, 2 * size);
break;
}
rad += QUARTER_PI;
case 'rectRot':
xOffset = Math.cos(rad) * radius;
yOffset = Math.sin(rad) * radius;
ctx.moveTo(x - xOffset, y - yOffset);
ctx.lineTo(x + yOffset, y - xOffset);
ctx.lineTo(x + xOffset, y + yOffset);
ctx.lineTo(x - yOffset, y + xOffset);
ctx.closePath();
break;
case 'crossRot':
rad += QUARTER_PI;
case 'cross':
xOffset = Math.cos(rad) * radius;
yOffset = Math.sin(rad) * radius;
ctx.moveTo(x - xOffset, y - yOffset);
ctx.lineTo(x + xOffset, y + yOffset);
ctx.moveTo(x + yOffset, y - xOffset);
ctx.lineTo(x - yOffset, y + xOffset);
break;
case 'star':
xOffset = Math.cos(rad) * radius;
yOffset = Math.sin(rad) * radius;
ctx.moveTo(x - xOffset, y - yOffset);
ctx.lineTo(x + xOffset, y + yOffset);
ctx.moveTo(x + yOffset, y - xOffset);
ctx.lineTo(x - yOffset, y + xOffset);
rad += QUARTER_PI;
xOffset = Math.cos(rad) * radius;
yOffset = Math.sin(rad) * radius;
ctx.moveTo(x - xOffset, y - yOffset);
ctx.lineTo(x + xOffset, y + yOffset);
ctx.moveTo(x + yOffset, y - xOffset);
ctx.lineTo(x - yOffset, y + xOffset);
break;
case 'line':
xOffset = Math.cos(rad) * radius;
yOffset = Math.sin(rad) * radius;
ctx.moveTo(x - xOffset, y - yOffset);
ctx.lineTo(x + xOffset, y + yOffset);
break;
case 'dash':
ctx.moveTo(x, y);
ctx.lineTo(x + Math.cos(rad) * radius, y + Math.sin(rad) * radius);
break;
}
ctx.fill();
if (options.borderWidth > 0) {
ctx.stroke();
}
}