Merge pull request #9 from TimGoTheCreator/unique-pt

Update to unique pointers

Author: TimGoTheCreator

src/gravity/octree.h

@@ -13,6 +13,7 @@
 #include "../struct/particle.h"
 #include <vector>
 #include <cmath>
+#include <memory> // Required for unique_ptr
 #include "dt/softening.h"
 #include "floatdef.h"
 
@@ -22,35 +23,50 @@ struct Octree {
     real x, y, z;        // node center
     real size;           // half-width
     bool leaf = true;
-    Particle* body = nullptr;
-    Octree* child[8] = { nullptr };
+    Particle* body = nullptr; 
+    
+    // Ownership: unique_ptr handles memory automatically
+    std::unique_ptr<Octree> child[8] = { nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr };
 
     // Quadrupole tensor
     real Qxx = 0, Qyy = 0, Qzz = 0;
     real Qxy = 0, Qxz = 0, Qyz = 0;
 
     Octree(real X, real Y, real Z, real S) : x(X), y(Y), z(Z), size(S), m(0), cx(0), cy(0), cz(0) {}
 
-    ~Octree() { for (auto c : child) delete c; }
+    // Destructor is now empty; unique_ptr cleans up children automatically
+    ~Octree() = default;
 
     int index(const Particle& p) const {
         return (p.x > x) * 1 + (p.y > y) * 2 + (p.z > z) * 4;
     }
 
-    Octree* createChild(int idx) {
+    // Returns unique_ptr to take ownership
+    std::unique_ptr<Octree> createChild(int idx) {
         real hs = size * real(0.5);
-        return new Octree(x + ((idx & 1) ? hs : -hs), y + ((idx & 2) ? hs : -hs), z + ((idx & 4) ? hs : -hs), hs);
+        return std::make_unique<Octree>(
+            x + ((idx & 1) ? hs : -hs), 
+            y + ((idx & 2) ? hs : -hs), 
+            z + ((idx & 4) ? hs : -hs), 
+            hs
+        );
     }
 
     void insert(Particle* p) {
-        if (leaf && body == nullptr) { body = p; return; }
+        if (leaf && body == nullptr) { 
+            body = p; 
+            return; 
+        }
+        
         if (leaf) {
             leaf = false;
-            Particle* old = body; body = nullptr;
+            Particle* old = body; 
+            body = nullptr;
             int idx = index(*old);
             if (!child[idx]) child[idx] = createChild(idx);
             child[idx]->insert(old);
         }
+        
         int idx = index(*p);
         if (!child[idx]) child[idx] = createChild(idx);
         child[idx]->insert(p);
@@ -65,7 +81,7 @@ struct Octree {
         }
 
         m = 0; cx = cy = cz = 0;
-        for (auto c : child) {
+        for (auto& c : child) { // Use reference to unique_ptr
             if (!c) continue;
             c->computeMass();
             if (c->m == 0) continue;
@@ -75,10 +91,9 @@ struct Octree {
         if (m > 0) { cx /= m; cy /= m; cz /= m; }
 
         Qxx = Qyy = Qzz = Qxy = Qxz = Qyz = 0;
-        for (auto c : child) {
+        for (auto& c : child) {
             if (!c || c->m == 0) continue;
             real rx = c->cx - cx; real ry = c->cy - cy; real rz = c->cz - cz;
-            // Internal node softening to match force calculation
             real r2 = rx * rx + ry * ry + rz * rz + (size * size * real(0.01));
             real mchild = c->m;
             Qxx += mchild * (3 * rx * rx - r2);
@@ -91,6 +106,7 @@ struct Octree {
     }
 };
 
+// Traverse using raw pointers (non-owning observer)
 inline void bhAccel(Octree* node, const Particle& p, real theta, real& ax, real& ay, real& az) {
     if (!node || node->m == 0) return;
     if (node->leaf && node->body == &p) return;
@@ -131,5 +147,7 @@ inline void bhAccel(Octree* node, const Particle& p, real theta, real& ax, real&
         return;
     }
 
-    for (auto c : node->child) if (c) bhAccel(c, p, theta, ax, ay, az);
+    for (auto& c : node->child) {
+        if (c) bhAccel(c.get(), p, theta, ax, ay, az); // Use .get() to pass raw pointer
+    }
 }

src/gravity/step.h

@@ -14,95 +14,79 @@
 #include "floatdef.h"
 #include "octree.h"
 #include <vector>
+#include <memory>
+#include <algorithm>
 
 inline void Step(std::vector<Particle> &p, real dt) {
-  if (p.empty())
-    return;
+  if (p.empty()) return;
 
   real theta = 0.5;
   real half = dt * real(0.5);
 
-  auto buildTree = [&](Octree *&root) {
-    // Compute bounding box
+  // Helper lambda that returns a unique_ptr
+  auto buildTree = [&]() -> std::unique_ptr<Octree> {
     real minx = +1e30, miny = +1e30, minz = +1e30;
     real maxx = -1e30, maxy = -1e30, maxz = -1e30;
 
-    for (auto &a : p) {
-      minx = std::min(minx, a.x);
-      miny = std::min(miny, a.y);
-      minz = std::min(minz, a.z);
-      maxx = std::max(maxx, a.x);
-      maxy = std::max(maxy, a.y);
-      maxz = std::max(maxz, a.z);
+    for (const auto &a : p) {
+      minx = std::min(minx, a.x); miny = std::min(miny, a.y); minz = std::min(minz, a.z);
+      maxx = std::max(maxx, a.x); maxy = std::max(maxy, a.y); maxz = std::max(maxz, a.z);
     }
 
     real cx = (minx + maxx) * 0.5;
     real cy = (miny + maxy) * 0.5;
     real cz = (minz + maxz) * 0.5;
-    real dx = maxx - minx;
-    real dy = maxy - miny;
-    real dz = maxz - minz;
+    real size = std::max({maxx - minx, maxy - miny, maxz - minz}) * real(0.5);
 
-    real size = std::max(dx, std::max(dy, dz)) * real(0.5);
+    if (size <= 0) size = 1;
 
-    if (size <= 0)
-      size = 1; // safety
-
-    root = new Octree(cx, cy, cz, size);
+    // Create the owned root
+    auto root = std::make_unique<Octree>(cx, cy, cz, size);
 
     for (auto &a : p)
       root->insert(&a);
 
     root->computeMass();
+    return root; 
   };
 
-  // =========================
-  // First Kick (dt/2)
-  // =========================
+  // --- First Kick (dt/2) ---
   {
-    Octree *root = nullptr;
-    buildTree(root);
+    std::unique_ptr<Octree> root = buildTree();
 
 #pragma omp parallel for schedule(static)
     for (int i = 0; i < (int)p.size(); i++) {
       real ax = 0, ay = 0, az = 0;
-      bhAccel(root, p[i], theta, ax, ay, az);
+      // Pass the raw pointer via .get() for the traversal
+      bhAccel(root.get(), p[i], theta, ax, ay, az);
 
       p[i].vx += ax * half;
       p[i].vy += ay * half;
       p[i].vz += az * half;
     }
-
-    delete root;
+    // No 'delete root' needed! It happens automatically here.
   }
 
-// =========================
-// Drift (dt)
-// =========================
+  // --- Drift (dt) ---
 #pragma omp parallel for schedule(static)
   for (int i = 0; i < (int)p.size(); i++) {
     p[i].x += p[i].vx * dt;
     p[i].y += p[i].vy * dt;
     p[i].z += p[i].vz * dt;
   }
 
-  // =========================
-  // Second Kick (dt/2)
-  // =========================
+  // --- Second Kick (dt/2) ---
   {
-    Octree *root = nullptr;
-    buildTree(root);
+    std::unique_ptr<Octree> root = buildTree();
 
 #pragma omp parallel for schedule(static)
     for (int i = 0; i < (int)p.size(); i++) {
       real ax = 0, ay = 0, az = 0;
-      bhAccel(root, p[i], theta, ax, ay, az);
+      bhAccel(root.get(), p[i], theta, ax, ay, az);
 
       p[i].vx += ax * half;
       p[i].vy += ay * half;
       p[i].vz += az * half;
     }
-
-    delete root;
   }
 }