only draw interpolated markers in visible data range

Author: leeoniya

site/static/index.html

@@ -236,21 +236,23 @@
 
                                     const interpolatedColorWithAlpha = "#fcb0f15f";
 
-                                    ctx.save();
                                     ctx.strokeStyle = interpolatedColorWithAlpha;
                                     ctx.beginPath();
 
-                                    u.data[0].forEach((v, j) => {
+                                    let [ i0, i1 ] = u.series[0].idxs;
+
+                                    for (let j = i0; j <= i1; j++) {
+                                        let v = u.data[0][j];
+
                                         if (isInterpolated(j)) {
                                             let cx = Math.round(u.valToPos(v, 'x', true));
                                             ctx.moveTo(cx, top);
                                             ctx.lineTo(cx, top + height);
                                         }
-                                    });
+                                    }
 
                                     ctx.closePath();
                                     ctx.stroke();
-                                    ctx.restore();
                                 },
                             ]
                         },