fix(g-canvas): bbox calculation for path is incorrect when angle is 0…

… and π, close antvis#254

packages/g-canvas/src/util/path.ts

@@ -167,6 +167,9 @@ function getExtraFromSegmentWithAngle(segment, lineWidth) {
   const angleCurrent = Math.acos(
     (currentAndPre + currentAndNext - preAndNext) / (2 * Math.sqrt(currentAndPre) * Math.sqrt(currentAndNext))
   );
+  if (Math.sin(angleCurrent) === 0) {
+    return 0;
+  }
   // 这里不考虑在水平和垂直方向的投影，直接使用最大差值
   // 由于上层统一加减了二分之一线宽，这里需要进行弥补
   return lineWidth * (1 / Math.sin(angleCurrent / 2)) + lineWidth / 2 || 0;

packages/g-canvas/tests/bugs/issue-254-spec.js

@@ -0,0 +1,30 @@
+const expect = require('chai').expect;
+import Canvas from '../../src/canvas';
+
+const dom = document.createElement('div');
+document.body.appendChild(dom);
+dom.id = 'c1';
+
+describe('#254', () => {
+  const canvas = new Canvas({
+    container: dom,
+    width: 600,
+    height: 600,
+  });
+
+  it('bbox calculation for path should consider angle of 0 and PI', () => {
+    const shape = canvas.addShape({
+      type: 'path',
+      attrs: {
+        path: [['M', 300, 500], ['L', 300, 375], ['L', 300, 500], ['Z']],
+        lineWidth: 5,
+        stroke: 'red',
+      },
+    });
+    const bbox = shape.getBBox();
+    expect(bbox.minX).eqls(297.5);
+    expect(bbox.minY).eqls(372.5);
+    expect(bbox.maxX).eqls(302.5);
+    expect(bbox.maxY).eqls(502.5);
+  });
+});