Add sink module

Split !1066 (closed)

Here I am simply adding the modules for the sink particles but do not use them.

src/sink/Default/sink.h

+/*******************************************************************************
+ * This file is part of SWIFT.
+ * Coypright (c) 2020 Loic Hausammann (loic.hausammann@epfl.ch)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ ******************************************************************************/
+#ifndef SWIFT_DEFAULT_SINK_H
+#define SWIFT_DEFAULT_SINK_H
+
+#include <float.h>
+
+/* Local includes */
+#include "dimension.h"
+#include "kernel_hydro.h"
+#include "minmax.h"
+#include "sink_part.h"
+
+/**
+ * @brief Computes the time-step of a given sink particle.
+ *
+ * @param sp Pointer to the sink-particle data.
+ */
+__attribute__((always_inline)) INLINE static float sink_compute_timestep(
+    const struct sink* const sp) {
+
+  return FLT_MAX;
+}
+
+/**
+ * @brief Initialises the sink-particles for the first time
+ *
+ * This function is called only once just after the ICs have been
+ * read in to do some conversions.
+ *
+ * @param sp The particle to act upon
+ * @param props The properties of the sink model.
+ */
+__attribute__((always_inline)) INLINE static void sink_first_init_sink(
+    struct sink* sp) {
+
+  sp->time_bin = 0;
+}
+
+/**
+ * @brief Prepares a sink-particle for its interactions
+ *
+ * @param sp The particle to act upon
+ */
+__attribute__((always_inline)) INLINE static void sink_init_sink(
+    struct sink* sp) {}
+
+/**
+ * @brief Predict additional particle fields forward in time when drifting
+ *
+ * @param sp The particle
+ * @param dt_drift The drift time-step for positions.
+ */
+__attribute__((always_inline)) INLINE static void sink_predict_extra(
+    struct sink* restrict sp, float dt_drift) {}
+
+/**
+ * @brief Sets the values to be predicted in the drifts to their values at a
+ * kick time
+ *
+ * @param sp The particle.
+ */
+__attribute__((always_inline)) INLINE static void sink_reset_predicted_values(
+    struct sink* restrict sp) {}
+
+/**
+ * @brief Kick the additional variables
+ *
+ * @param sp The particle to act upon
+ * @param dt The time-step for this kick
+ */
+__attribute__((always_inline)) INLINE static void sink_kick_extra(
+    struct sink* sp, float dt) {}
+
+#endif /* SWIFT_DEFAULT_SINK_H */