One Dimensional Cellular Automata ( C Practice Project )

1dca.c

#include<stdio.h>
#include<stdint.h>
#include<string.h>
#include<stdlib.h>
#include<time.h>
#include<stdbool.h>

// Enables or disables random initialization
const int RANDOM_INIT = true;

// --------------- Begin code

// Converts a 3 cell (bit) neighborhood to an integer describing it's state
uint8_t getNeighborhoodValue (uint8_t w[], int index) {
    unsigned char neighborhood = w[index-1]*4 + w[index]*2 + w[index+1]*1; // 4 = 100, 2 = 010, 1 = 001
    return neighborhood;
}

// Replaces 1 and 0 with more visualizable characters
char* getCellChar(uint8_t c) {
    if (c == 0)
        return " ";
    else
        return "█";
}

int randFromRange(int min, int max) {
    return (rand() % (max - min + 1)) + min;
}


int main (int argc, char* argv[]) {
    srand(time(NULL));

    // rule can be expressed as a single byte
    uint8_t rule = randFromRange(0,255);
    
    // Rows to print / loop count
    const int loops = 100;
    
    if (argc > 1)
        sscanf(argv[1], "%d", &rule);
        sscanf(argv[2], "%d", &loops);

    printf("Generating rule %d for %d generations\n", rule, loops);
    

    uint8_t world[100] = {};
    uint8_t world_new_state[100] = {};
    const int WORLD_SIZE = sizeof world / sizeof world[0];

    if (RANDOM_INIT == true) {
        
        for (int i = 0; i < sizeof world; i ++) {
            world[i] = rand()%2;
        }
    } else {
         // flip a cell
        world[WORLD_SIZE-1] = 1;
    }

    for (int i = loops; i > 0; i--) {
        // Iterate on cells
        for (int j = 0; j < WORLD_SIZE; j++) {

            // Display current cell
            printf(getCellChar(world[j])); 

            // Get the outcome for the current neighborhood based on the game rule.
            world_new_state[j] = (rule >> getNeighborhoodValue(world, j)) & 1; 
        }

        // Overwrite current state with new world state
        memcpy(world, world_new_state, sizeof world);
        printf("\n");
    }
}