Basic Conways Game Of Life in C

glider.txt

#..
.##
##.

gol.c

// compile with gcc gol.c -o gol -lncurses
#include <time.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "ncurses.h"

#define TIME_TEST 1
#ifdef TIME_TEST
FILE * timeLog = NULL;
#endif

int getValue(int x, int y, int * grid, unsigned int width, unsigned int height);
void setValue(int value, int x, int y, int * grid, int * needsCheck, unsigned int width, unsigned int height);
void clearGrid(int * grid, unsigned int size, int value);
void drawGrid(int * grid, unsigned int width, unsigned int height);
void update(int * grid, int * needsCheck, unsigned int width, unsigned int height);
int getNeighbours(unsigned int x, unsigned int y, int * grid, unsigned int width, unsigned int height);
void randomGrid(int * grid, int * needsCheck, unsigned int size);
bool loadFile(char * filename, int * grid, int * needsCheck, unsigned int width, unsigned int height);

int main(void) {
  srand( time(NULL) );
  WINDOW * win = initscr();
  noecho();
  raw();
  
  if(has_colors() == FALSE) {
    endwin();
    exit(1);
  }
  start_color();
  init_pair(0, COLOR_BLACK, COLOR_BLACK);
  init_pair(1, COLOR_BLACK, COLOR_WHITE);

  unsigned int maxX, maxY;
  getmaxyx(win, maxY, maxX);
  unsigned int bottomY = maxY;
  maxY -= 1;

  int grid [maxX * maxY];
  int needsCheck[maxX * maxY];
  //clearGrid(grid, maxX * maxY, 0);
  //clearGrid(needsCheck, maxX * maxY, 1);
  randomGrid(grid, needsCheck, maxX * maxY);
  
  int speed = 10;
  int oldSpeed = 10;
  timeout(speed);

  char speedStr[10];
  sprintf(speedStr, "%d", speed);
  
#ifdef TIME_TEST
  timeLog = fopen("timelog.txt", "w");
  if(timeLog == NULL) {
    endwin();
    printf("Error opening file for writing\n");
    exit(1);
  }
#endif
  
  unsigned char showDebug = FALSE;
  unsigned char quit = FALSE;
  while(!quit) {
    update(grid, needsCheck, maxX, maxY);
    if(showDebug) {
      drawGrid(needsCheck, maxX, maxY);
    }
    else {
      drawGrid(grid, maxX, maxY);
    }
    move(bottomY, 0);
    addstr(speedStr);
    char c = getch();
    switch(c) {
      case 'q':
        quit = TRUE;
        break;
      case 'r':
        randomGrid(grid, needsCheck, maxX * maxY);
        break;
      case '-':
        speed += 10;
        timeout(speed);
        sprintf(speedStr, "%d", speed);
        move(bottomY, 0);
        addstr("          ");
        break;
      case '+':
        speed -= 10;
        if(speed < 0) {
          speed = 0;
        }
        sprintf(speedStr, "%d", speed);
        timeout(speed);
        move(bottomY, 0);
        addstr("          ");
        break;
      case ' ':
        if(speed < 0) {
          speed = oldSpeed;
        }
        else {
          oldSpeed = speed;
          speed = -1;
        }
        sprintf(speedStr, "%d", speed);
        timeout(speed);
        move(bottomY, 0);
        addstr("          ");
        break;
      case 'd':
        showDebug = !showDebug;
        break;
      case 'c':
        clearGrid(grid, maxX * maxY, 0);
        clearGrid(needsCheck,maxX * maxY, 0);
        break;
      case 'l':
        loadFile("infinite.txt", grid, needsCheck, maxX, maxY);
        break;
      case 'g':
        loadFile("glider.txt", grid, needsCheck, maxX, maxY);
        break;
      case 'o':
        loadFile("gilders.txt", grid, needsCheck, maxX, maxY);
        break;
    }
  }

  //printf("%d", getValue(10, 10, grid, maxX, maxY));
  
  endwin();
#ifdef TIME_TEST
  if(timeLog != NULL) {
    fclose(timeLog);
  }
#endif
  return 0;
}

int getValue(int x, int y, int * grid, unsigned int width, unsigned int height) {
  if(x <= -1) {
    x = width - 1;
  }
  else if(x >= width) {
    x = 0;
  }
  if(y <= -1) {
    y = height - 1;
  }
  else if(y >= height) {
    y = 0;
  }
  return grid[x +(width*y)];
  //return getValue(x, y, grid, width, height);
}

void setValue(int value, int x, int y, int * grid, int * needsCheck, unsigned int width, unsigned int height) {
  if(x <= -1) {
    x = width - 1;
  }
  else if(x >= width) {
    x = 0;
  }
  if(y <= -1) {
    y = height - 1;
  }
  else if(y >= height) {
    y = 0;
  }
  grid[x + (width*y)] = value;

  if(needsCheck != NULL) {
    // give the option of sending in null for big batches of changes like clears
    // this way we dont repeatedly set things to a value
    // also if a value hasnt changed
    needsCheck[x + (width*y)] = 1; // we have changed
    // next do our moores neighbours
    int i;
    for(i = x-1; i <= x+1; i ++) {
      int j;
      for(j = y-1; j<= y+1; j ++) {
        setValue(1, i, j, needsCheck, NULL, width, height);
      }
    }

  }
}

void clearGrid(int * grid, unsigned int size, int value) {
  unsigned int i;
  for(i = 0; i < size; i ++) {
    grid[i] = value;
  }
}

void drawGrid(int * grid, unsigned int width, unsigned int height) {
  int x, y;
  for(y = 0; y < height; y ++) {
    for(x = 0; x < width; x ++) {
      move(y, x);
      if(getValue(x, y, grid, width, height) > 0) {
        attron(COLOR_PAIR(1));
        addch('#');
        attroff(COLOR_PAIR(1));
      }
      else {
        attron(COLOR_PAIR(0));
        addch(' ');
        attroff(COLOR_PAIR(0));
      }
    }
  }
}

void update(int * grid, int * needsCheck, unsigned int width, unsigned int height) {
#ifdef TIME_TEST
  clock_t start = clock();
#endif
  int newGrid[width * height];
  int newNeedsCheck[width * height];
  clearGrid(newNeedsCheck, width * height, 0);
  unsigned int x, y;
  for(x = 0; x < width; x ++) {
    for(y = 0; y < height; y ++) {
      int state = getValue(x, y, grid, width, height);
      if(getValue(x, y, needsCheck, width, height) == 0) {
        setValue(state, x, y, newGrid, NULL, width, height); 
        continue;
      }
      int neighbours = getNeighbours(x, y, grid, width, height);
      if(state == 0) {
        // dead
        if(neighbours == 3) {
          setValue(1, x, y, newGrid, newNeedsCheck, width, height);
        }
        else {
          // no change
          setValue(0, x, y, newGrid, NULL, width, height);
        }
      }
      else if(state == 1) {
        // alive
        if(neighbours < 2 || neighbours > 3) {
          setValue(0, x, y, newGrid, newNeedsCheck, width, height);
        }
        else {
          // no change
          setValue(1, x, y, newGrid, NULL, width, height);
        }
      }
    }
  }

  // replace old grid
  unsigned int i;
  for(i = 0; i < width*height; i ++) {
    grid[i] = newGrid[i];
    needsCheck[i] = newNeedsCheck[i];
  }
#ifdef TIME_TEST
  clock_t stop = clock();
  double diff =  ((double) (stop - start)) / CLOCKS_PER_SEC;
  fprintf(timeLog, "%.20f\n", diff);
#endif
}

int getNeighbours(unsigned int x, unsigned int y, int * grid, unsigned int width, unsigned int height) {
  int total = 0;
  total += getValue(x-1, y, grid, width, height);
  total += getValue(x-1, y-1, grid, width, height);
  total += getValue(x-1, y+1, grid, width, height);
  total += getValue(x, y-1, grid, width, height);
  total += getValue(x, y+1, grid, width, height);
  total += getValue(x+1, y-1, grid, width, height);
  total += getValue(x+1, y+1, grid, width, height);
  total += getValue(x+1, y, grid, width, height);
  return total;
}

void randomGrid(int * grid, int * needsCheck, unsigned int size) {
  unsigned int i;
  for(i = 0; i < size; i ++) {
    grid[i] = rand() % 10 + 1 < 5 ? 0 : 1;
    needsCheck[i] = 1;
  }

}

bool loadFile(char * filename, int * grid, int * needsCheck, unsigned int width, unsigned int height) {
  FILE * fp = NULL;
  char line[80];
  fp = fopen(filename, "rt");
  if(fp == NULL) return false;
  clearGrid(grid, width * height, 0);
  unsigned int y = 0;
  while(fgets(line, 80, fp) != NULL && y < height) {
    unsigned int length = strlen(line);
    unsigned int x;
    for(x = 0; x < length && x < width; x ++) {
      char c = line[x];
      if(c == '#') {
        setValue(1, x, y, grid, NULL, width, height);
      }
      //else {
      //  setValue(0, x, y, grid, width, height);
      //}
    }
    y ++;
  }

  fclose(fp);
  clearGrid(needsCheck, width * height, 1);
  return TRUE;
}

infinite.txt

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