God I hate CPP

DLASystem.cpp

@@ -34,17 +34,17 @@ void DLASystem::clearParticles() {
 // set the value of a grid cell for a particular position
 // note the position has the initial particle at (0,0)
 // but this corresponds to the middle of the grid array ie grid[ halfGrid ][ halfGrid ]
-void DLASystem::setGrid(double pos[], int val) {
+void DLASystem::setGrid(std::array<double, 2> pos, int val) {
     *index_grid(pos) = val;
 }
 
 // read the grid cell for a given position
-int DLASystem::readGrid(double pos[]) {
+int DLASystem::readGrid(std::array<double, 2> pos) {
     return *index_grid(pos);
 }
 
 // add a particle to the system at a specific position
-void DLASystem::addParticle(double pos[]) {
+void DLASystem::addParticle(std::array<double, 2> pos) {
     // create a new particle
     Particle *p = new Particle(pos);
     // push_back means "add this to the end of the list"
@@ -58,10 +58,8 @@ void DLASystem::addParticle(double pos[]) {
 // if we hit an occupied site then we do nothing except print a message
 // (this should never happen)
 void DLASystem::addParticleOnAddCircle() {
-    double pos[2];
     double theta = rgen.random01() * 2 * M_PI;
-    pos[0] = ceil(addCircle * cos(theta));
+    std::array<double, 2> pos{ceil(addCircle * cos(theta)), ceil(addCircle * sin(theta))};
-    pos[1] = ceil(addCircle * sin(theta));
     if (readGrid(pos) == 0) {
         addParticle(pos);
     } else {
@@ -72,7 +70,7 @@ void DLASystem::addParticleOnAddCircle() {
 // send back the position of a neighbour of a given grid cell
 // NOTE: there is no check that the neighbour is inside the grid,
 // this has to be done separately...
-void DLASystem::setPosNeighbour(double setpos[], double pos[], int val) {
+void DLASystem::setPosNeighbour(std::array<double, 2> &setpos, const std::array<double, 2> pos, int val) {
     switch (val) {
         case 0:
             setpos[0] = pos[0] + 1.0;
@@ -95,7 +93,7 @@ void DLASystem::setPosNeighbour(double setpos[], double pos[], int val) {
 
 // when we add a particle to the cluster, we should update the cluster radius
 // and the sizes of the addCircle and the killCircle
-void DLASystem::updateClusterRadius(double pos[]) {
+void DLASystem::updateClusterRadius(std::array<double, 2> pos) {
     double newRadius = distanceFromOrigin(pos);
     if (newRadius > clusterRadius) {
         clusterRadius = newRadius;
@@ -122,7 +120,7 @@ void DLASystem::updateClusterRadius(double pos[]) {
 // make a random move of the last particle in the particleList
 void DLASystem::moveLastParticle() {
     int direction = rgen.randomInt(4);  // pick a random number in the range 0-3, which direction do we hop?
-    double newpos[2];
+    std::array<double, 2> newpos{};
 
     Particle *lastP = particleList[this->particleList.size() - 1];
 
@@ -154,7 +152,7 @@ int DLASystem::checkStick() {
     int result = 0;
     // loop over neighbours
     for (int i = 0; i < 4; i++) {
-        double checkpos[2];
+        std::array<double, 2> checkpos;
         setPosNeighbour(checkpos, lastP->pos, i);
         // if the neighbour is occupied...
         if (readGrid(checkpos) == 1)
@@ -188,7 +186,7 @@ DLASystem::DLASystem(Config config)
 //    }
 
     // Add particle to the centre of the grid to start
-    double pos[] = {0.0, 0.0};
+    std::array<double, 2> pos{0.0, 0.0};
     addParticle(pos);
 
     // Make sure to include the central location in our csv.

DLASystem.h

@@ -62,7 +62,7 @@ private:
 
     int frame;
 
-    int *index_grid(double pos[]) {
+    int *index_grid(std::array<double, 2> pos) {
         int halfGrid = gridSize / 2;
         int i = (int) (pos[0] + halfGrid);
         int j = (int) (pos[1] + halfGrid);
@@ -97,15 +97,15 @@ public:
     void pauseRunning() { running = false; }
 
     // if pos is outside the cluster radius then set clusterRadius to be the distance to pos.
-    void updateClusterRadius(double pos[]);
+    void updateClusterRadius(std::array<double, 2> pos);
 
     // set and read grid entries associated with a given position
-    void setGrid(double pos[], int val);
+    void setGrid(std::array<double, 2> pos, int val);
 
-    int readGrid(double pos[]);
+    int readGrid(std::array<double, 2> pos);
 
     // return the distance of a given point from the origin
-    double distanceFromOrigin(double pos[]) {
+    double distanceFromOrigin(std::array<double, 2> pos) {
         return sqrt(pos[0] * pos[0] + pos[1] * pos[1]);
     }
 
@@ -115,14 +115,14 @@ public:
     void setParticleInactive() { lastParticleIsActive = 0; }
 
     // add a particle at pos
-    void addParticle(double pos[]);
+    void addParticle(std::array<double, 2> pos);
 
     // add a particle at a random point on the addCircle
     void addParticleOnAddCircle();
 
     // assign setpos to the position of a neighbour of pos
     // which neighbour we look at is determined by val (=0,1,2,3)
-    void setPosNeighbour(double setpos[], double pos[], int val);
+    void setPosNeighbour(std::array<double, 2> &setpos, std::array<double, 2> pos, int val);
 
     // this attempts to move the last particle in the List to a random neighbour
     // if the neighbour is occupied then nothing happens

Particle.h

@@ -1,22 +1,14 @@
 #pragma once
+#include <array>
 
 class Particle {
 public:
     static const int dim = 2;  // we are in two dimensions
-    double *pos;  // pointer to an array of size dim, to store the position
+    std::array<double, dim> pos{};
 
-    // default constructor
+    // constructor, with a specified initial pos
-    Particle() {
+    explicit Particle(std::array<double, dim> pos) {
-        pos = new double[dim];
+        this->pos[0] = pos[0];
+        this->pos[1] = pos[1];
     }
-
-    // constructor, with a specified initial position
-    Particle(double set_pos[]) {
-        pos = new double[dim];
-        for (int d = 0; d < dim; d++)
-            pos[d] = set_pos[d];
-    }
-
-    // destructor
-    ~Particle() { delete[] pos; }
 };