Create vtk_save.h

Author: TimGoTheCreator

src/io/vtk_save.h

@@ -0,0 +1,38 @@
+#pragma once
+#include <vector>
+#include <string>
+#include <fstream>
+#include "../struct/particle.h"
+
+inline void SaveVTK(const std::vector<Particle>& p, const std::string& filename)
+{
+    std::ofstream out(filename);
+    if (!out) return;
+
+    const size_t N = p.size();
+    out << "# vtk DataFile Version 3.0\n";
+    out << "NEXT snapshot\n";
+    out << "ASCII\n";
+    out << "DATASET POLYDATA\n";
+
+    // draw points
+    out << "POINTS " << N << " float\n";
+    for (const auto& a : p)
+        out << a.x << " " << a.y << " " << a.z << "\n";
+
+    // draw vertices
+    out << "VERTICES " << N << " " << N*2 << "\n";
+    for (size_t i = 0; i < N; i++)
+        out << "1 " << i << "\n";
+
+    // that too
+    out << "POINT_DATA " << N << "\n";
+    out << "VECTORS velocity float\n";
+    for (const auto& a : p)
+        out << a.vx << " " << a.vy << " " << a.vz << "\n";
+
+    out << "SCALARS mass float 1\n";
+    out << "LOOKUP_TABLE default\n";
+    for (const auto& a : p)
+        out << a.m << "\n";
+}