conflict resolved

advection/src/interpolate.cpp

@@ -0,0 +1,47 @@
+#include "interpolate.h"
+
+using namespace std;
+
+Vel bilinearinterpolate(const UVGrid &uvGrid, int time, double lat, double lon) {
+    double latStep = uvGrid.latStep();
+    double lonStep = uvGrid.lonStep();
+    int timeStep = uvGrid.timeStep();
+
+    int latIndex = (lat - uvGrid.lats[0]) / latStep;
+    int lonIndex = (lon - uvGrid.lons[0]) / lonStep;
+    int timeIndex = (time - uvGrid.times[0]) / timeStep;
+
+    double timeRatio = (static_cast<double>(time) - uvGrid.times[timeIndex]) / timeStep;
+    double latRatio = (lat - uvGrid.lats[latIndex]) / latStep;
+    double lonRatio = (lon - uvGrid.lons[lonIndex]) / lonStep;
+
+    Vel point = {0, 0};
+    for (int timeOffset = 0; timeOffset <= 1; timeOffset++) {
+        for (int latOffset = 0; latOffset <= 1; latOffset++) {
+            for (int lonOffset = 0; lonOffset <= 1; lonOffset++) {
+                auto vertex = uvGrid[
+                        timeIndex + 1 < uvGrid.timeSize ? timeIndex + timeOffset : timeIndex,
+                                latIndex + 1 < uvGrid.latSize ? latIndex + latOffset : latIndex,
+                                lonIndex + 1 < uvGrid.lonSize ? lonIndex + lonOffset : lonIndex
+                ];
+
+                double timeRation = (1 - timeOffset) * (1 - timeRatio) + timeOffset * timeRatio;
+                double latRation = (1 - latOffset) * (1 - latRatio) + latOffset * latRatio;
+                double lonRation = (1 - lonOffset) * (1 - lonRatio) + lonOffset * lonRatio;
+                point += timeRation * latRation * lonRation * vertex;
+            }
+        }
+    }
+
+    return point;
+}
+
+vector<Vel> bilinearinterpolation(const UVGrid &uvGrid, vector<tuple<int, double, double>> points) {
+    vector<Vel> result;
+    result.reserve(points.size());
+    for (auto [time, lat, lon]: points) {
+        result.push_back(bilinearinterpolate(uvGrid, time, lat, lon));
+    }
+
+    return result;
+}