adds saving and loading history to and from disk

frontend/src/graph/line.ts

@@ -34,8 +34,36 @@ export class PointLine {
         return left + (this.data[left].x < x ? 1 : 0);
     }
 
-    insert(point: Point) {
+    insert(point: Point, maximum_separation?: number) {
         const index = this.find_index(point.x);
         this.data.splice(index, 0, point);
+        if (maximum_separation !== undefined) {
+            this.reduce_to_maximum_separation(maximum_separation, [index - 1, index + 1]);
+        }
+    }
+
+    reduce_to_maximum_separation(maximum_separation: number, range?: [number, number]) {
+        if (maximum_separation <= 0) {
+            return;
+        }
+        // Add a default range if it does not exist
+        range = range || [1, this.data.length - 2];
+        // clamp it to the bounds
+        range = [Math.max(1, range[0]), Math.min(this.data.length - 2, range[1])];
+
+        // Loop over the indices in the range (backwards so removals don't break anything)
+        for (let i = range[1]; i >= range[0]; i--) {
+            const x_previous = this.data[i - 1].x;
+            const x_current = this.data[i].x;
+            const x_next = this.data[i + 1].x;
+
+            const separation_before = x_current - x_previous;
+            const separation_after = x_next - x_current;
+
+            // If the data points are too close on both sides then delete this point
+            if (separation_before < maximum_separation && separation_after < maximum_separation) {
+                this.data.splice(i, 1);
+            }
+        }
     }
 }