From 894d62b01f8fb8e0ef1db7d401a155e1e89ee97a Mon Sep 17 00:00:00 2001
From: Enzo DE CARVALHO BITTENCOURT <enzo.decarvalhobittencourt@ensiie.eu>
Date: Fri, 22 Mar 2024 03:51:28 +0100
Subject: [PATCH] Upload New File
---
main.c | 387 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 387 insertions(+)
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+/******************************************************************************
+
+Copyright (c) Anzo.
+Simple Terminal based Boids
+
+===============================================================================
+
+ This program is free software: you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free Software
+Foundation, either version 3 of the License, or (at your option) any later
+version.
+
+ This program is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along with
+this program. If not, see <https://www.gnu.org/licenses/>.
+
+===============================================================================
+
+small c file with boids represented in terminal, with only the libc as
+dependency. This was mostly done using Conrad Parker pseudocode boid
+implementation (http://www.kfish.org/boids/pseudocode.html), and thus lacks
+optimizations.
+
+===============================================================================
+COMPILING AND REQUIREMENTS :
+
+terminal must support truecolor.
+
+compile this file with linkage to math library (generally -lm)
+`
+gcc main.c -lm -o boids
+`
+
+the executable takes two optional args : width and height of the board
+example :
+`
+boids 50 120
+`
+
+Theres a bunch of defines down there that parametrizes the boids. tinkering
+with them maybe fun idk
+******************************************************************************/
+
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <sys/ioctl.h>
+#include <time.h>
+#include <fcntl.h>
+#include <sys/param.h>
+#include <string.h>
+#include <math.h>
+
+int width;
+int height;
+
+struct winsize w;
+
+int w_c; //"center" coordinates
+int h_c;
+
+/*
++---------------------------------+
+| | h_c   | <-- your screen
+|-------+-----------------+ |
+| w_c | | |
+| | | Â |
+| | content | Â Â |
+| | | Â |
+| +-----------------+ Â |
+| |
++---------------------------------+
+*/
+
+char* grid;
+char* prevGrid;
+
+int DEBUG;
+int PAUSE;
+
+void initFlushGrid()
+{
+ int h, w;//current h w
+
+ int v,r,g,b;
+
+ for (int i=0; i<width*height; i++)
+ {
+ h = (i/width) + h_c + 1;
+ w = (i%width) + w_c + 1;
+
+ //int v = (!grid[i]) ? 0 : MIN(grid[i]*10 + 50, 255); //value
+ int r = (!grid[i]) ? 0 : MIN(grid[i]*35 + 0, 255);
+ int g = (!grid[i]) ? 0 : MIN(grid[i]*15 + 100, 255);
+ int b = (!grid[i]) ? 0 : MIN(grid[i]*10 + 75, 255);
+ printf("\033[%i;%iH\033[48;2;%i;%i;%im ", h, w, r, g, b);
+ }
+
+ fflush(stdout);
+ return;
+}
+
+void flushGrid()
+{
+ int h, w;//current h w
+
+ for (int i=0; i<width*height; i++)
+ {
+ if (grid[i] != prevGrid[i])
+ {
+ h = (i/width) + h_c + 1;
+ w = (i%width) + w_c + 1;
+ //int v = (!grid[i]) ? 0 : MIN(grid[i]*10 + 50, 255); //value
+ int r = (!grid[i]) ? 0 : MIN(grid[i]*35 + 0, 255);
+ int g = (!grid[i]) ? 0 : MIN(grid[i]*15 + 100, 255);
+ int b = (!grid[i]) ? 0 : MIN(grid[i]*10 + 75, 255);
+
+ printf("\033[%i;%iH\033[48;2;%i;%i;%im ", h, w, r, g, b);
+ }
+ }
+
+ printf("\033[0;0H");
+
+ fflush(stdout);
+ return;
+}
+
+//random float between 0 and 1
+float randf()
+{
+ return (float) random() / RAND_MAX;
+}
+
+float norm(float x, float y)
+{
+ return sqrtf(x*x + y*y);
+}
+
+#define BOIDS_AMOUNT 500
+#define MAX_SPEED 0.4
+#define BOUNCE_BACK
+
+#define SEEING_DISTANCE 5
+
+//rule 1 cst
+#define TO_CENTER_FACTOR 0.01
+
+//rule 2 cst
+#define AWAY_DIST 0.2
+#define KEEP_ME_AWAY_FACTOR 2
+
+//rule 3 cst
+#define MATCH_VEL_FACTOR 0.125
+
+/* a boid is a point + velocity*/
+typedef struct
+{
+ float x;
+ float y;
+ float vx;
+ float vy;
+} boid;
+
+boid *boidsList;
+
+float boidDist(boid a, boid b)
+{
+ return norm(a.x - b.x, a.y - b.y);
+}
+
+int inSight(boid a, boid b)
+{
+ return (boidDist(a,b) < (float)SEEING_DISTANCE) ? 1 : 0;
+}
+
+//randomly put them boids in the board.
+//with random init velocity.
+void initBoids()
+{
+ boid* b;
+ float normb;
+ for (int i=0; i < BOIDS_AMOUNT; i++)
+ {
+ b = &boidsList[i];
+
+ boidsList[i].x = randf() * width;
+ boidsList[i].y = randf() * height;
+
+ boidsList[i].vx = randf() * 2 - 1;
+ boidsList[i].vy = randf() * 2 - 1;
+ }
+
+ //limit velocity
+ normb = norm(b->vx, b->vy);
+ if ( normb > MAX_SPEED)
+ {
+ b->vx = (b->vx / normb) * MAX_SPEED;
+ b->vy = (b->vy / normb) * MAX_SPEED;
+ }
+}
+
+//apply the three rules of boid mvmt
+void UpdateBoids()
+{
+ boid* b;
+ float normb;
+
+ float r1vx;
+ float r1vy;
+
+ float r2vx;
+ float r2vy;
+
+ float r3vx;
+ float r3vy;
+
+ int N = 0; //number of boids in sight
+
+ for (int i=0; i < BOIDS_AMOUNT; i++)
+ {
+ b = &boidsList[i];
+
+ //rule 1 : move toward percieved center (no "seeing distance")
+ //-----------------------------------------------------------
+ N = 0;
+ r1vx = 0;
+ r1vy = 0;
+
+ for (int j=0; j < BOIDS_AMOUNT; j++)
+ {
+ if (i==j){continue;}
+ if (inSight(*b, boidsList[j]))
+ {
+ r1vx += boidsList[j].x;
+ r1vy += boidsList[j].y;
+ N += 1;
+ }
+ }
+
+ r1vx = r1vx / MAX(N, 1);
+ r1vy = r1vy / MAX(N, 1);
+ //here, vx and vy holds barycenter of all other boids
+
+ r1vx = (r1vx - b->x) * TO_CENTER_FACTOR;
+ r1vy = (r1vy - b->y) * TO_CENTER_FACTOR;
+ // correct vector
+
+ //rule 2 : try not to collide
+ //----------------------------------------------------------
+ N = 0;
+ r2vx = 0;
+ r2vy = 0;
+ for (int j=0; j < BOIDS_AMOUNT; j++)
+ {
+ if (i==j){continue;}
+ normb = norm(b->x - boidsList[j].x, b->y - boidsList[j].y);
+ if ( normb < AWAY_DIST)
+ {
+ r2vx = (b->x - boidsList[j].x) * KEEP_ME_AWAY_FACTOR;
+ r2vy = (b->y - boidsList[j].y) * KEEP_ME_AWAY_FACTOR;
+ }
+ }
+
+ //rule 3 : match velocity of peers (no seeing distance)
+ //---------------------------------------------------------
+ N = 0;
+ r3vx = 0;
+ r3vy = 0;
+
+ for (int j=0; j < BOIDS_AMOUNT; j++)
+ {
+ if (i==j){continue;}
+ if (inSight(*b, boidsList[j]))
+ {
+ r3vx += boidsList[j].vx;
+ r3vy += boidsList[j].vy;
+ N += 1;
+ }
+ }
+
+ r3vx = (r3vx / MAX(N,1)) * MATCH_VEL_FACTOR;
+ r3vy = (r3vy / MAX(N,1)) * MATCH_VEL_FACTOR;
+
+ //add velocity
+ b->vx += r1vx + r2vx + r3vx;
+ b->vy += r1vy + r2vy + r3vy;
+
+ //limit velocity
+ normb = norm(b->vx, b->vy);
+ if ( normb > MAX_SPEED)
+ {
+ b->vx = (b->vx / normb) * MAX_SPEED;
+ b->vy = (b->vy / normb) * MAX_SPEED;
+ }
+
+#ifdef BOUNCE_BACK
+ //bounce back b inside board
+ if (b->x + b->vx > width || b->x + b->vx < 0)
+ {b->vx *= -1;}
+
+ if (b->y + b->vy > height || b->y + b->vy < 0)
+ {b->vy *= -1;}
+
+#else
+ //warp pos b inside the board
+ if (b->x + b->vx > width)
+ {b->x = 0 + b->vx;}
+
+ if (b->x + b->vx < 0)
+ {b->x = width + b->vx;}
+
+ if (b->vy + b->y > height)
+ {b->y = height + b->vy;}
+
+ if (b->y + b->vy < 0)
+ {b->y = height + b->vy;}
+#endif
+
+ //update pos
+ b->x += b->vx;
+ b->y += b->vy;
+ }
+}
+//reset the grid to 0, and
+//add one to each cell of where a boid is.
+void renderBoidsToGrid()
+{
+ for (int i = 0; i < width*height; i++)
+ {grid[i]=0;}
+
+ int pos; // index in grid
+ for (int ib = 0; ib < BOIDS_AMOUNT ; ib++)
+ {
+ pos = ((int)boidsList[ib].y)*width + (int)boidsList[ib].x;
+ grid[pos] += 1;
+ //printf("grid[%i] : %i\n", pos, grid[pos]);
+ }
+}
+
+int main(int argc, char** argv)
+{
+ DEBUG = 0;
+
+ //init rng with seed
+ srandom(time(NULL));
+
+ //init grids
+ ioctl(0, TIOCGWINSZ, &w);
+ if (argc == 3)
+ {
+ width=atoi(argv[1]);
+ height=atoi(argv[2]);
+ }
+ else
+ {
+ width=w.ws_col;
+ height=w.ws_row;
+ }
+
+ w_c = (w.ws_col - width) / 2;
+ h_c = (w.ws_row - height) / 2;
+
+ grid = calloc((width*height),sizeof(char));
+ prevGrid = calloc((width*height),sizeof(char));
+
+ //init boids
+ boidsList = calloc(BOIDS_AMOUNT, sizeof(boid));
+
+ printf("\033[1J");
+
+ initBoids();
+
+ renderBoidsToGrid();
+ initFlushGrid();
+
+ while(1)
+ {
+ usleep(2500);
+ memcpy(prevGrid, grid, width*height*sizeof(char));
+ UpdateBoids();
+ renderBoidsToGrid();
+ flushGrid();
+ }
+}
--
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