Revert "Merge branch 'smail' into lbaumberger"

This reverts commit 1cf29bfdd8, reversing
changes made to 1b79bd15f4.

forces.cpp

@@ -1,10 +1,11 @@
 #include "forces.hpp"
 #include <math.h>
 
-// # Done
+// # 8 flops = 5 MULTs, 2 ADD, 1 SQRT
 double w(Vector2d e, Vector2d f) {
   if (e.dot(f) >= f.norm() * cos_phi)
     return 1.0;
+  else
     return c;
 }
 
@@ -26,10 +27,8 @@ void compute_acceleration_term(Pedestrian *p) {
   Vector2d desired_velocity = p->e * p->desired_v0;
   // $\vec{v}_{\alpha}(t)$
   Vector2d actual_velocity = p->curr_vel;
-
-  double tau_alpha_inv = 1 / tau_alpha;
-
-  p->F_i += (desired_velocity - actual_velocity) * tau_alpha_inv;
+  // # 6 flops = 4 ADDs, 2 DIVs
+  p->f_i += (desired_velocity - actual_velocity) / tau_alpha;
 }
 
 // # 55(N - 1) = 55N - 55 flops
@@ -102,12 +101,12 @@ void compute_repulsive_effects_from_pedestrians(Pedestrian *pedestrians, Pedestr
 // # 48 n_obstacles flops = 192 flops
 void compute_repulsive_effects_from_borders(Board &board, Pedestrian *p) {
 
-  Vector2d *borders = B.borders;
-  int n_borders = B.n_borders;
+  Obstacle *obstacles = board.obstacles;
+  int n_borders = board.n_obstacles;
 
   for (int i = 0; i < n_borders; i++) {
 
-    Vector2d border = borders[i];
+    Obstacle obstacle = obstacles[i];
 
     // # 17 flops
     // $\vec{r}_{\alpha B}$

forces.hpp

@@ -37,6 +37,8 @@ const double dt = 0.001;
 
 double w(Vector2d e, Vector2d f);
 
+double g(double v_max_alpha, double w_alpha_norm);
+
 void compute_acceleration_term(Pedestrian *p);
 
 void compute_repulsive_effects_from_pedestrians(Pedestrian *P, Pedestrian *p, int N);

main.cpp

@@ -2,14 +2,15 @@
 #include "forces.hpp"
 #include "math.h"
 #include "pedestrian.hpp"
+#include "tsc_x86.h"
 #include "vector2d.hpp"
+#include <fstream>
+#include <iostream>
+#include <tuple>
+#include <vector>
 
-double g(double v_max_alpha, double w_alpha_norm) {
-  if (w_alpha_norm <= v_max_alpha) {
-    return 1;
-  }
-  return v_max_alpha / w_alpha_norm;
-}
+#define BOARD_WIDTH 10.0
+#define BOARD_LENGTH 50.0
 
 using namespace std;
 
@@ -23,20 +24,44 @@ using namespace std;
 
 Pedestrian *init_pedestrians(int n_p) {
   Pedestrian *P = new Pedestrian[n_p];
-  for (int i = 0; i < n_p; i++) {
-    P[i] = Pedestrian();
+  std::random_device rd; // use for truly random simulation
+  // std::mt19937 gen(rd());                                    // use rd instead of 42 as seed for real randomness
+  std::mt19937 gen(42);                                      // use fixed seed for reproducibility
+  std::normal_distribution<double> velocity_gen(1.34, 0.26); // 1.34 and 0.26 are the mean and stdrd deviation used in paper
+  std::uniform_real_distribution<double> x_gen(2, BOARD_LENGTH - 2);
+  std::uniform_real_distribution<double> y_gen(2, BOARD_WIDTH - 2);
+  for (int i = 0; i < n_p / 2; i++) {
+    double y = y_gen(gen);
+    Vector2d start_pos = Vector2d(x_gen(gen), y);
+    Vector2d destination = Vector2d(BOARD_LENGTH + 300, BOARD_WIDTH / 2);
+    // double desired_v0 = velocity_gen(gen);
+    double desired_v0;
+    do {
+      desired_v0 = velocity_gen(gen);
+    } while (desired_v0 <= 0.1); // to avoid small values (Way below the social force -> that would make the walk backwards) (we discovered some weird stuff in the simulation)
+    double v_max = 1.3 * desired_v0;
+    P[i] = Pedestrian(WHITE, (destination - start_pos) / (destination - start_pos).norm() * desired_v0, start_pos, (destination - start_pos) / (destination - start_pos).norm(), v_max, desired_v0, destination, Vector2d());
+  }
+
+  for (int i = n_p / 2; i < n_p; i++) {
+    double y = y_gen(gen);
+    Vector2d start_pos = Vector2d(x_gen(gen), y);
+    Vector2d destination = Vector2d(-300, BOARD_WIDTH / 2);
+    // double desired_v0 = velocity_gen(gen);
+    double desired_v0;
+    do {
+      desired_v0 = velocity_gen(gen);
+    } while (desired_v0 <= 0.1);
+    double v_max = 1.3 * desired_v0;
+    P[i] = Pedestrian(BLACK, (destination - start_pos) / (destination - start_pos).norm() * desired_v0, start_pos, (destination - start_pos) / (destination - start_pos).norm(), v_max, desired_v0, destination, Vector2d(0, 0));
   }
   return P;
 }
 
-Board init_board(int width, int length) {
-  Vector2d obs[] = {Vector2d(2.0, 1.0), Vector2d(4.0, 1.0), Vector2d(6.0, 2.0), Vector2d(6.0, 4.0)};
-  return Board(width, length, 4, obs);
-}
-
 int main(int argc, const char *argv[]) {
 
-  Board B = init_board(10, 15);
+  Obstacle obs[] = {};
+  Board board = Board(BOARD_LENGTH, BOARD_WIDTH, 0, obs);
 
   int n_p = atoi(argv[1]);
   int n_iter = atoi(argv[2]);
@@ -51,13 +76,17 @@ int main(int argc, const char *argv[]) {
 
   Pedestrian *pedestrians = init_pedestrians(n_p);
 
-  for (int t = 0; t < n_iter; t++) {
+  // # Start here or right after function signature
+  uint64_t start = start_tsc();
 
+  // # (8 + 55N - 55 + 192 + 4 + 8 + 4 + 10)*n_p*n_iter
+  for (int t = 0; t < n_iter; t++) {
+    // Pass1: conmpute all forces from the current state
     for (int i = 0; i < n_p; i++) {
 
       Pedestrian &p = pedestrians[i];
 
-      p.F_i.reset();
+      p.f_i.reset();
 
       // # 8 flops
       //

pedestrian.hpp

@@ -2,6 +2,9 @@
 #include "random"
 #include "vector2d.hpp"
 
+// For visual simulation
+enum Color { BLACK, WHITE };
+
 struct Pedestrian {
   Color color;
   // $\vec{v}_{\alpha}(t)$