make it compile with cmake.

simulation/main.cpp

@@ -0,0 +1,44 @@
+
+#include <print>
+#include <iostream>
+// opencl
+#include <CL/opencl.hpp>
+// duckdb
+#include "duckdb/duckdb.hpp"
+
+#include "opencl_helper.hpp"
+#include "simulation.hpp"
+
+#define DB_FILE "../simulation.duckdb"
+#define KERNEL_DIR "../kernels/"
+#define SQLCMD_DIR "../sqlcmd/"
+
+
+int main(){
+  // open database
+  duckdb_database db;
+  duckdb_connection dbcon;
+
+  if (duckdb_open(DB_FILE, &db) == DuckDBError) {
+    std::cout << "DB file can not be found" << std::endl;
+    exit(1);
+  }
+
+  if (duckdb_connect(db, &dbcon) == DuckDBError) {
+    std::cout << ("DB NOT Connected") << std::endl;
+    exit(1);
+  }
+
+  std::cout << "DB Connected" << std::endl;
+
+  // Setup OpenCL
+  cl::Device cl_device = OpenCL::select_devices();
+  cl::Context cl_context ({cl_device});
+
+  run_simulation(dbcon, cl_device , cl_context);
+
+  duckdb_disconnect(&dbcon);
+  duckdb_close(&db);
+
+  return 0;
+}