Measured depth linear interpolation (equinor#401)

* Added measured depth values to well trajectory example data.

* Added mathjs dependency.

Co-authored-by: Havard Bjerke <[email protected]>

package.json

@@ -53,6 +53,7 @@
         "leaflet": "^1.6.0",
         "leaflet-draw": "^1.0.4",
         "lodash": "^4.17.21",
+        "mathjs": "^9.4.2",
         "nebula.gl": "^0.22.3",
         "react": "^17.0.2",
         "react-dom": "^17.0.2",

src/lib/components/DeckGLMap/layers/wells/wellsLayer.ts

@@ -2,7 +2,8 @@ import { CompositeLayer } from "@deck.gl/core";
 import { CompositeLayerProps } from "@deck.gl/core/lib/composite-layer";
 import { GeoJsonLayer, PathLayer } from "@deck.gl/layers";
 import { RGBAColor } from "@deck.gl/core/utils/color";
-import { PickInfo } from "@deck.gl/core/lib/deck";
+import { PickInfo } from "deck.gl";
+import { subtract, distance, dot } from "mathjs";
 import { interpolateRgbBasis } from "d3-interpolate";
 import { color } from "d3-color";
 
@@ -103,6 +104,48 @@ function squared_distance(a, b): number {
     return dx * dx + dy * dy;
 }
 
+function getMd(pickInfo): number | null {
+    if (!pickInfo.object.properties || !pickInfo.object.geometry) return null;
+
+    const measured_depths = pickInfo.object.properties.md[0];
+    const trajectory = pickInfo.object.geometry.geometries[1].coordinates;
+
+    // Get squared distance from survey point to picked point.
+    const d2 = trajectory.map((element) =>
+        squared_distance(element, pickInfo.coordinate)
+    );
+
+    // Enumerate squared distances.
+    let index: number[] = Array.from(d2.entries());
+
+    // Sort by squared distance.
+    index = index.sort((a: number, b: number) => a[1] - b[1]);
+
+    // Get the nearest indexes.
+    const index0 = index[0][0];
+    const index1 = index[1][0];
+
+    // Get the nearest MD values.
+    const md0 = measured_depths[index0];
+    const md1 = measured_depths[index1];
+
+    // Get the nearest survey points.
+    const survey0 = trajectory[index0];
+    const survey1 = trajectory[index1];
+
+    const dv = distance(survey0, survey1) as number;
+
+    // Calculate the scalar projection onto segment.
+    const v0 = subtract(pickInfo.coordinate, survey0);
+    const v1 = subtract(survey1, survey0);
+    const scalar_projection: number = dot(v0 as number[], v1 as number[]) / dv;
+
+    // Interpolate MD value.
+    const c0 = scalar_projection / dv;
+    const c1 = dv - c0;
+    return (md0 * c1 + md1 * c0) / dv;
+}
+
 export interface WellsPickInfo extends PickInfo<unknown> {
     logName?: string;
     propertyValue?: number;
@@ -207,6 +250,17 @@ export default class WellsLayer extends CompositeLayer<
     }: {
         info: PickInfo<unknown>;
     }): WellsPickInfo | PickInfo<unknown> {
+        if (!info.object) return info;
+
+        // Return MD if a trajectory has been picked.
+        const measured_depth = getMd(info);
+        if (measured_depth != null) {
+            return {
+                ...info,
+                propertyValue: measured_depth,
+            };
+        }
+
         if (!info.object || !(info.object as LogCurveDataType)?.data)
             return info;