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263-0007-00L-Advanced-Syste…/main.cpp
T

147 lines
4.3 KiB
C++

#include "board.hpp"
#include "forces.hpp"
#include "math.h"
#include "pedestrian.hpp"
#include "vector2d.hpp"
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;
}
using namespace std;
// Numer of pedestrians
// $n_p$
// const int n_p = 100;
// Number of iterations
// $n_{iter}$
// const int n_iter = 100;
Pedestrian *init_pedestrians(int n_p) {
Pedestrian *P = new Pedestrian[n_p];
for (int i = 0; i < n_p; i++) {
P[i] = Pedestrian();
}
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);
int n_p = atoi(argv[1]);
int n_iter = atoi(argv[2]);
// Logic to get/dump the simulation data
const int dump_interval = 50; // dump every 5 iterations -> 20 fps (since dt = 0.01)
const char *dump_path = (argc >= 4) ? argv[3] : nullptr;
std::vector<std::tuple<int, int, double, double, int>> samples; // t, id, x, y, color
if (dump_path)
samples.reserve((size_t)n_iter / dump_interval * n_p);
Pedestrian *pedestrians = init_pedestrians(n_p);
for (int t = 0; t < n_iter; t++) {
for (int i = 0; i < n_p; i++) {
Pedestrian &p = pedestrians[i];
p.F_i.reset();
// # 8 flops
//
// $\vec{F}_\alpha(\vec{v}_\alpha, v^0_\alpha \vec{e}_\alpha) \vec{e}_\alpha(t) = \frac{1}{\tau_\alpha}(v^0_\alpha \vec{e}_\alpha - \vec{v}_\alpha)$
//
compute_acceleration_term(&p);
// # 55N - 55 flops
//
// $\sum_{\beta} \vec{F}_{\alpha\beta}(\vec{e}_{\alpha}, \vec{r}_{\alpha} - \vec{r}_{\beta})$
//
compute_repulsive_effects_from_pedestrians(pedestrians, &p, n_p);
// # 192 flops
//
// $\sum_{B} \vec{F}_{\alpha B}(\vec{e}_{\alpha}, \vec{r}_{\alpha} - \vec{r}_{B})$
//
compute_repulsive_effects_from_borders(board, &p);
}
// Pass2: integrate the forces and update the current state
for (int i = 0; i < n_p; i++) {
Pedestrian &p = pedestrians[i];
// # 4 flops = 2 ADDs, 2 MULTs
// integrate preferred velocity: dw/dt = F (Eq. 10)
p.w = p.w + p.f_i * dt;
// Vector2d w_alpha = p.curr_vel + p.f_i * dt; // commented since this was using p.curr_vel instead of p.w (different from paper)
// # 8 flops = 2 MULTs, 2 DIVs, 1 SQRT, 2 MULTs, 1 ADD
p.curr_vel = p.w * g(p.v_max, p.w.norm());
// # 4 flops = 2 ADDs, 2 MULTs
//
// $\vec{r}_i^{t+1} += \vec{r}^t_i + v^t_idt$
//
p.curr_pos = p.curr_pos + p.curr_vel * dt;
// how to handle if a pedestrian reached the end of our simulation/end of the hallway
// The option we do here is to just "teleport" the person back to the beginning
// the good thing is we will have a constant flow of pedestrians and in the simulation we should see how lines build up
if (p.color == WHITE && p.curr_pos.x > (BOARD_LENGTH - 1.5)) {
// basically just keep the y position and reset the x
p.curr_pos.x = 1.0;
// p.destination.y = p.curr_pos.y;
}
if (p.color == BLACK && p.curr_pos.x < 1.5) {
p.curr_pos.x = BOARD_LENGTH - 1.0;
// p.destination.y = p.curr_pos.y;
}
// # 10 flops = 5 ADDs, 2 DIVs, 1 SQRT, 2 MULTs
p.e = (p.destination - p.curr_pos) / (p.destination - p.curr_pos).norm();
// if we have a dump path/file we wanna save the data for visualisation
if (dump_path && (t % dump_interval == 0)) {
samples.emplace_back(t, i, p.curr_pos.x, p.curr_pos.y, p.color);
}
}
}
long long W = (long long)(8 + 55 * n_p - 55 + 192 + 4 + 8 + 4 + 10) * n_p * n_iter;
std::cout << "W(n): ";
std::cout << W;
std::cout << " flops\n";
double T = stop_tsc(start);
std::cout << "T(n): ";
std::cout << T;
std::cout << " cycles\n";
double P = W / T;
std::cout << "P(n): ";
std::cout << P;
std::cout << " flops/cycle\n";
// now we wanna save the data to a csv
if (dump_path) {
std::ofstream out(dump_path);
out << "time,id,x,y,color\n";
for (auto &[t, id, x, y, c] : samples) {
out << t << ',' << id << ',' << x << ',' << y << ',' << c << '\n';
}
}
delete[] pedestrians;
return 0;
}