1 files changed, 59 insertions, 0 deletions
diff --git a/src/export.h b/src/export.h
new file mode 100644
index 0000000..a3d38ec
--- /dev/null
+++ b/src/export.h
@@ -0,0 +1,59 @@
+#pragma once
+
+#include <span>
+#include <fstream>
+
+namespace export_format {
+
+template <std::floating_point T>
+void vtk(Cuboid c, std::span<T> rho, std::span<T> u, std::string path) {
+	std::ofstream fout;
+	fout.open(path.c_str());
+
+	fout << "# vtk DataFile Version 3.0\n";
+	fout << "lbm_output\n";
+	fout << "ASCII\n";
+	fout << "DATASET RECTILINEAR_GRID\n";
+	fout << "DIMENSIONS " << c[0] << " " << c[1] << " " << c[2] << "\n";
+
+	fout << "X_COORDINATES " << c[0] << " float\n";
+	for (std::size_t iX=0; iX < c[0]; ++iX) {
+		fout << iX << " ";
+	}
+
+	fout << "\nY_COORDINATES " << c[1] << " float\n";
+	for (std::size_t iY=0; iY < c[1]; ++iY) {
+		fout << iY << " ";
+	}
+
+	fout << "\nZ_COORDINATES " << c[2] << " float\n";
+	for (std::size_t iZ=0; iZ < c[2]; ++iZ) {
+		fout << iZ << " ";
+	}
+	fout << "\nPOINT_DATA " << c.volume() << "\n";
+
+	fout << "VECTORS velocity float\n";
+	for (std::size_t iZ=0; iZ < c[2]; ++iZ) {
+		for (std::size_t iY=0; iY < c[1]; ++iY) {
+			for (std::size_t iX=0; iX < c[0]; ++iX) {
+				const std::size_t iCell = c.index(iX,iY,iZ);
+				fout << u[iCell] << " " << u[c.volume() + iCell] << " " << u[2*c.volume() + iCell] << "\n";
+			}
+		}
+	}
+
+	fout << "SCALARS density float 1\n";
+	fout << "LOOKUP_TABLE default\n";
+	for (std::size_t iZ=0; iZ < c[2]; ++iZ) {
+		for (std::size_t iY=0; iY < c[1]; ++iY) {
+			for (std::size_t iX=0; iX < c[0]; ++iX) {
+				const std::size_t iCell = c.index(iX,iY,iZ);
+				fout << rho[iCell] << "\n";
+			}
+		}
+	}
+
+	fout.close();
+}
+
+}