refactor: allow for other solver implementations

1 files changed, 18 insertions, 0 deletions

diff --git a/src/solver/midpoint.rs b/src/solver/midpoint.rs
new file mode 100644
index 0000000..c5a01c4
--- /dev/null
+++ b/src/solver/midpoint.rs
@@ -0,0 +1,18 @@
+use crate::particle_system::{ParticleSystem, Scalar};
+use super::{PhaseSpace, Solver};
+
+impl Solver for ParticleSystem {
+    fn step(&mut self, dt: Scalar) {
+        let mut state = self.collect_phase_space();
+
+        // Shift to the midpoint
+        self.scatter_phase_space(&&PhaseSpace {
+            0: state.0.clone() + self.compute_derivative().0 * dt / 2.0,
+        });
+
+        state.0 += self.compute_derivative().0 * dt;
+        self.scatter_phase_space(&state);
+
+        self.t += dt;
+    }
+}