GameOfLife/main.c

#include <SDL2/SDL.h>
#include <stdlib.h>

#include "config.h"

#define SCREEN_WIDTH (ROWS * CELL_SIZE)
#define SCREEN_HEIGHT (COLUMNS * CELL_SIZE)

int gameRunning = 1;
int simulation = 0;
int mouseHold = 0;

int board[COLUMNS][ROWS];

SDL_Renderer *renderer;
SDL_Window *window;
SDL_Event event;

void init() {
  SDL_Init(SDL_INIT_VIDEO);
  SDL_CreateWindowAndRenderer(SCREEN_WIDTH, SCREEN_HEIGHT, SDL_WINDOW_SHOWN,
                              &window, &renderer);
  if (!window) {
    printf("%s", SDL_GetError());
    exit(1);
  }
  SDL_SetWindowTitle(window, "Game Of Life");
}

void destroy() {
  SDL_DestroyRenderer(renderer);
  SDL_DestroyWindow(window);
  SDL_Quit();
}

void clear_board() {
  if (!simulation) {
    for (int i = 0; i < COLUMNS; i++) {
      for (int j = 0; j < ROWS; j++) {
        board[i][j] = 0;
      }
    }
  }
}

void processMotion(int x, int y) {
  if (mouseHold && !simulation && x >= 0 && y >= 0 && x < SCREEN_WIDTH &&
      y < SCREEN_HEIGHT) {
    int cellX = x / CELL_SIZE;
    int cellY = y / CELL_SIZE;
    board[cellY][cellX] = 1;
  }
}

void handleEvents() {
  while (SDL_PollEvent(&event)) {
    switch (event.type) {
    case SDL_QUIT:
      gameRunning = 0;
      break;

    case SDL_MOUSEMOTION:
      processMotion(event.motion.x, event.motion.y);
      break;

    case SDL_MOUSEBUTTONUP:
      mouseHold = 0;
      break;

    case SDL_KEYDOWN:
      if (event.key.keysym.sym == SDLK_c)
        clear_board();
      break;

    case SDL_MOUSEBUTTONDOWN:
      switch (event.button.button) {
      case SDL_BUTTON_LEFT:
        mouseHold = 1;
        processMotion(event.button.x, event.button.y);
        break;

      case SDL_BUTTON_RIGHT:
        simulation = (simulation + 1) % 2;
        break;
      }
      break;
    }
  }
}

void render() {
  SDL_SetRenderDrawColor(renderer, 47, 49, 54, 255);
  SDL_RenderClear(renderer);

  SDL_Rect rect;
  rect.w = CELL_SIZE;
  rect.h = CELL_SIZE;

  for (int i = 0; i < COLUMNS; i++) {
    for (int j = 0; j < ROWS; j++) {
      rect.x = j * CELL_SIZE;
      rect.y = i * CELL_SIZE;
      if (board[i][j] == 1) {
        SDL_SetRenderDrawColor(renderer, 185, 187, 190, 255);
        SDL_RenderFillRect(renderer, &rect);
      } else {
        SDL_SetRenderDrawColor(renderer, 54, 57, 63, 255);
        SDL_RenderDrawRect(renderer, &rect);
      }
    }
  }

  if (simulation)
    SDL_Delay(1000 / GENERATIONS_PER_SECOND);
  else
    SDL_Delay(1000 / 120);

  SDL_RenderPresent(renderer);
}

void move() {
  int new_board[COLUMNS][ROWS];

  for (int i = 0; i < COLUMNS; i++) {
    for (int j = 0; j < ROWS; j++) {
      int count = 0;
      for (int di = i - 1; di <= i + 1; di++) {
        for (int dj = j - 1; dj <= j + 1; dj++) {
          if ((di == i && dj == j) || (di < 0 || dj < 0) ||
              (di >= COLUMNS || j >= ROWS))
            continue;

          if (board[di][dj] == 1)
            count++;
        }
      }

      if (board[i][j] == 1 && (count == 2 || count == 3))
        new_board[i][j] = 1;
      else if (board[i][j] == 0 && count == 3)
        new_board[i][j] = 1;
      else
        new_board[i][j] = 0;
    }
  }

  memcpy(board, new_board, sizeof(int) * ROWS * COLUMNS);
}

void gameLoop() {
  while (gameRunning) {
    handleEvents();
    if (simulation)
      move();
    render();
  }
}

int main(int argv, char **args) {
  init();
  gameLoop();
  destroy();

  return 0;
}