Code

/*
Snake Game inspired by Google snake game
player controls snake within a grid to food which makes the snake longer. The aim being to get the longest snake possible
CONTROLS: ('w' UP)('a' LEFT)('s' DOWN)('d' DOWN)('q' QUIT)
*/


#include <stdio.h>
#include <stdlib.h>
#include <conio.h>
#include <time.h>
#include <windows.h>

#define GRIDX 40
#define GRIDY 20
#define INITIAL_SNAKE_LENGTH 3
#define MAX_SNAKE_LENGTH 100
#define DEADTIME 1


struct Position {
    int x;
    int y;
};

struct Snake {
    struct Position body[MAX_SNAKE_LENGTH];
    int length;
    char direction;
    int score;
};

struct Food {
    struct Position position;
    char symbol;
};


void initialize(struct Snake *snake, struct Food *food, int *refreshRate);//gets things started by initializing object members
void drawGrid(struct Snake *snake, struct Food *food);//Draws the grid and the snake in the grid
void update(struct Snake *snake, struct Food *food, clock_t *lastMoveTime, int *refreshRate);//Updates positions of all objects (snake and food) checks if snake has died and updates counters
void generateFoodPosition(struct Food *food);// Uses the rand and srand functions to generate a random x and y co-ordinate to give to the food
int isSnakeInsideGrid(struct Snake *snake);// checks if the snake is inside the grid and outputs '-1 for not in grid and '0' if in the grid
void Score_Board(struct Snake *snake);//Outputs the current high score and tells the user if they have beaten the high score. If they have it then writes to the file the users high score




int main() {
    int refreshRate = 100;
    struct Snake snake;
    struct Food food;
    char key;
    int gameOver = 0;
    clock_t lastMoveTime;

    initialize(&snake, &food, &refreshRate);
    drawGrid(&snake, &food);

    printf("Press any key to start...");
    _getch();

    lastMoveTime = clock();


    while (!gameOver)
        {
        if (_kbhit()) {
            key = _getch();

            switch (key)
            {
                case 'w':
                    if (snake.direction != 'd') {
                        snake.direction = 'u';
                    }
                    break;
                case 's':
                    if (snake.direction != 'u') {
                        snake.direction = 'd';
                    }
                    break;
                case 'a':
                    if (snake.direction != 'r') {
                        snake.direction = 'l';
                    }
                    break;
                case 'd':
                    if (snake.direction != 'l') {
                        snake.direction = 'r';
                    }
                    break;
                case 'q':
                    char goAgain;
                    printf("\n\nWould you like to play again?(Enter '0' for yes and '1' for no)\n");
                    scanf("%c", &goAgain);
                    if (goAgain == '0'){initialize(&snake, &food, &refreshRate);}
                    else if (goAgain != '0'){gameOver=1;}
                    break;
            }
        }
        update(&snake, &food, &lastMoveTime, &refreshRate);
        drawGrid(&snake, &food);
        Sleep(refreshRate);
    }

    printf("Game over!\n");
    //printf("You Scored:\t%i\n", snake.score);
    Score_Board(&snake);

    return 0;
}

void initialize(struct Snake *snake, struct Food *food, int *refreshRate) {
    snake->length = INITIAL_SNAKE_LENGTH;
    snake->direction = ' ';
    snake->score = 0;
    *refreshRate = 150;

    for (int i = 0; i < INITIAL_SNAKE_LENGTH; i++) {
        snake->body[i].x = GRIDX / 2 - INITIAL_SNAKE_LENGTH / 2 + i;
        snake->body[i].y = GRIDY / 2;
    }

    food->symbol = '*';
    generateFoodPosition(food);
}

void drawGrid(struct Snake *snake, struct Food *food) {
    system("cls");

    for (int i = 0; i <= GRIDY; i++)
    {
        for (int j = 0; j <= GRIDX; j++)
        {
            if (i == 0 || i == GRIDY) {
                printf("-");
            } else if (j == 0 || j == GRIDX) {
                printf("|");
            } else {
                int isSnakeBody = 0;

                for (int k = 0; k < snake->length; k++)
                {
                    if (snake->body[k].x == j && snake->body[k].y == i) {
                        printf("O");
                        isSnakeBody = 1;
                        break;
                    }
                }
                if (!isSnakeBody && food->position.x == j && food->position.y == i) {
                    printf("%c", food->symbol);
                } else if (!isSnakeBody) {
                    printf(" ");
                }
            }
        }
        printf("\n");
    }
}

void update(struct Snake *snake, struct Food *food, clock_t *lastMoveTime, int *refreshRate) {
    //updates snake body positions
    for (int i = snake->length - 1; i > 0; i--) {
        snake->body[i] = snake->body[i - 1];
    }
    //updates snake head position
    switch (snake->direction) {
        case 'u':
            snake->body[0].y--;
            break;
        case 'd':
            snake->body[0].y++;
            break;
        case 'l':
            snake->body[0].x--;
            break;
        case 'r':
            snake->body[0].x++;
            break;
    }
    //Checks if snake has been outside of the grid for too long
    if (isSnakeInsideGrid(snake) == -1) {
        clock_t currentTime = clock();
        double elapsedSeconds = (double)(currentTime - *lastMoveTime) / CLOCKS_PER_SEC;
        if (elapsedSeconds >= DEADTIME) {
            printf("Snake is outside the grid for too long. Game over!\n\n\n");
            int goAgain;
            Score_Board(snake);

            printf("\n\nWould you like to play again?(Enter '0' for yes and '1' for no)\n");
            scanf("%i", &goAgain);
            if (goAgain == 0){initialize(snake, food, refreshRate);}
            else if (goAgain != 0){exit(0);}
        }
    } else {
        *lastMoveTime = clock();
    }
    if (snake->body[0].x == food->position.x && snake->body[0].y == food->position.y) {
        snake->length++;
        snake->score ++;
        if (*refreshRate > 0){*refreshRate = *refreshRate - 10;}
        generateFoodPosition(food);
    }
}

void generateFoodPosition(struct Food *food) {
    srand(time(NULL));
    food->position.x = rand() % (GRIDX - 1) + 1;
    food->position.y = rand() % (GRIDY - 1) + 1;
}

int isSnakeInsideGrid(struct Snake *snake) {
    int headX = snake->body[0].x;
    int headY = snake->body[0].y;

    if (headX >= 1 && headX <= GRIDX - 1 && headY >= 1 && headY <= GRIDY - 1){return 0;}
    else{return -1;}
}

void Score_Board(struct Snake *snake)
{
    char score[100];

    FILE *scoreBoard;
    scoreBoard = fopen("ScoreBoard.txt", "r");

    if (scoreBoard != NULL)
    {
        //printf("FILE FOUND\n");
        printf("your score is:\t%i\n", snake->score);
        fgets(score, 100, scoreBoard);
        int highScore = atoi(score);printf("HIGHSCORE\t%i\n", highScore);
        if (highScore < snake->score)
        {
            printf("You broke the high score!!\n");
            fclose(scoreBoard);
            FILE *highScoreBroken;
            highScoreBroken = fopen("ScoreBoard.txt", "w");
            fprintf(highScoreBroken, "%i", snake->score);
            fclose(highScoreBroken);
        }else if (scoreBoard == NULL){printf("FILE NOT FOUND\n");fclose(scoreBoard);}
    }
}