From 3694480303af250259f6f794f0061bfc9c601fd5 Mon Sep 17 00:00:00 2001
From: Timothy Warren <twarren@nabancard.com>
Date: Fri, 10 Jan 2020 10:39:55 -0500
Subject: [PATCH] Add first two functions

---
 src/main.rs | 131 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 131 insertions(+)

diff --git a/src/main.rs b/src/main.rs
index e7a11a9..c6f7de4 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,3 +1,134 @@
+#![allow(
+    non_upper_case_globals,
+    non_camel_case_types,
+    non_snake_case,
+)]
+use std::mem;
+use std::arch::x86_64::*;
+use std::f64::consts::PI;
+
+#[repr(C)]
+struct body {
+    position: [f64; 3],
+    velocity: [f64; 3],
+    mass: f64,
+}
+
+const SOLAR_MASS: f64 = 4. * PI * PI;
+const DAYS_PER_YEAR: f64 = 365.24;
+const BODIES_COUNT: usize = 5;
+
+static mut solar_Bodies: [body; BODIES_COUNT] = [
+    body { // Sun
+        mass: SOLAR_MASS,
+        position: [0.; 3],
+        velocity: [0.; 3],
+    },
+    body { // Jupiter
+        mass: 9.54791938424326609e-04 * SOLAR_MASS,
+        position: [
+            4.84143144246472090e+00,
+            -1.16032004402742839e+00,
+            -1.03622044471123109e-01
+        ],
+        velocity: [
+            1.66007664274403694e-03 * DAYS_PER_YEAR,
+            7.69901118419740425e-03 * DAYS_PER_YEAR,
+            -6.90460016972063023e-05 * DAYS_PER_YEAR
+        ]
+    },
+    body { // Saturn
+        mass: 2.85885980666130812e-04 * SOLAR_MASS,
+        position: [
+            8.34336671824457987e+00,
+            4.12479856412430479e+00,
+            -4.03523417114321381e-01
+        ],
+        velocity: [
+            -2.76742510726862411e-03 * DAYS_PER_YEAR,
+            4.99852801234917238e-03 * DAYS_PER_YEAR,
+            2.30417297573763929e-05 * DAYS_PER_YEAR
+        ]
+    },
+    body { // Uranus
+        mass: 4.36624404335156298e-05 * SOLAR_MASS,
+        position: [
+            1.28943695621391310e+01,
+            -1.51111514016986312e+01,
+            -2.23307578892655734e-01
+        ],
+        velocity: [
+            2.96460137564761618e-03 * DAYS_PER_YEAR,
+            2.37847173959480950e-03 * DAYS_PER_YEAR,
+            -2.96589568540237556e-05 * DAYS_PER_YEAR
+        ]
+    },
+    body { // Neptune
+        mass: 5.15138902046611451e-05 * SOLAR_MASS,
+        position: [
+            1.53796971148509165e+01,
+            -2.59193146099879641e+01,
+            1.79258772950371181e-01
+        ],
+        velocity: [
+            2.68067772490389322e-03 * DAYS_PER_YEAR,
+            1.62824170038242295e-03 * DAYS_PER_YEAR,
+            -9.51592254519715870e-05 * DAYS_PER_YEAR
+        ]
+    },
+];
+
+unsafe fn offset_Momentum(bodies: *mut body) {
+    for i in 0..BODIES_COUNT {
+        for m in 0..3 {
+            (*bodies.add(0)).velocity[m] -=
+                (*bodies.add(i)).velocity[m]
+                * (*bodies.add(i)).mass / SOLAR_MASS;
+        }
+    }
+}
+
+unsafe fn output_Energy(bodies: *mut body) {
+    let mut energy = 0.;
+    for i in 0..BODIES_COUNT {
+        // Add the kinetic energy for each body.
+        energy += 0.5 * (*bodies.add(i)).mass * (
+            (*bodies.add(i)).velocity[0]
+                * (*bodies.add(i)).velocity[0]
+            + (*bodies.add(i)).velocity[1]
+                * (*bodies.add(i)).velocity[1]
+            + (*bodies.add(i)).velocity[2]
+                * (*bodies.add(i)).velocity[2]);
+
+        // Add the potential energy between this body and
+        // every other body
+        for j in i+1..BODIES_COUNT {
+            let mut position_Delta =
+                [mem::MaybeUninit::<f64>::uninit(); 3];
+
+            for m in 0..3 {
+                position_Delta[m].as_mut_ptr().write(
+                    (*bodies.add(i)).position[m]
+                        - (*bodies.add(j)).position[m]
+                );
+            }
+            let position_Delta: [f64; 3] =
+                mem::transmute(position_Delta);
+
+            energy -= (*bodies.add(i)).mass
+                * (*bodies.add(j)).mass
+                / f64::sqrt(
+                    position_Delta[0]*position_Delta[0]+
+                        position_Delta[1]*position_Delta[1]+
+                        position_Delta[2]*position_Delta[2]
+                );
+        }
+    }
+
+    // Output the total energy of the system
+    println!("{:.9}", energy);
+}
+
 fn main() {
     println!("Hello, world!");
 }