new.cpp

#include <SDL2/SDL.h>
#include <deque>
#include <vector>
#include <algorithm>
int main()
{
    SDL_Init(SDL_INIT_EVERYTHING);

    auto window = SDL_CreateWindow(
        "Snake Game",
        SDL_WINDOWPOS_CENTERED,
        SDL_WINDOWPOS_CENTERED,
        1000,
        1000,
        0
    );

    auto renderer = SDL_CreateRenderer(
        window,
        -1,
        0
    );

    SDL_Event e;
    bool running = true;
    int dir = 0;
    SDL_Rect head {
        500,
        500,
        10,
        10
    };
    // Snake Body Container

    std::deque<SDL_Rect> rq;
    // int size = 1;

    //apples Container

    std::vector<SDL_Rect> apples;
    for (int i = 0; i < 100; i++)
    {   
        apples.emplace_back(rand()%100*10, rand()%100*10, 10, 10);
    }

    enum Direction
    {
        DOWN,
        LEFT,
        RIGHT,
        UP
    };

    int size=1;

    while(running)
    {
        // Check Input
        while(SDL_PollEvent(&e))
        {
            if(e.type == SDL_QUIT)
            {
                running = false;
            }
            if(e.type == SDL_KEYDOWN)
            {
                if(e.key.keysym.sym == SDLK_DOWN) { dir = DOWN;}
                else if(e.key.keysym.sym == SDLK_LEFT) { dir = LEFT;}
                else if(e.key.keysym.sym == SDLK_UP) { dir = UP;}
                else if(e.key.keysym.sym == SDLK_RIGHT) { dir = RIGHT;}
            }
        }

        // Move

        switch (dir)
        {
            case DOWN:
                head.y += 10; break;
            case UP:
                head.y -= 10; break;
            case LEFT:
                head.x -= 10; break;
            case RIGHT:
                head.x += 10; break;
        }

        // Collision Detection with apples
        std::for_each(apples.begin(), apples.end(), [&](auto &apple)
        {
            if(head.x == apple.x && head.y == apple.y)
            {
                size += 10;
                apple.x = -10;
                apple.y = -10;
            }
        });

        // Collision detection with snake body

        std::for_each(rq.begin(), rq.end(), [&](auto& snake_segment)
        {
            if(head.x == snake_segment.x && head.y == snake_segment.y)
            {
                size = 1;
            }
        });

        // Add newest head to the snake

        rq.push_front(head);

        while(rq.size() > size)
            rq.pop_back();


        // Clear Window

        SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
        SDL_RenderClear(renderer);

        //Draw apples

        SDL_SetRenderDrawColor(renderer, 255, 0, 0, 255);
        std::for_each(apples.begin(), apples.end(), [&](auto& apple){
            SDL_RenderFillRect(renderer,&apple);
        });

        // Draw Body

        SDL_SetRenderDrawColor(renderer, 255, 255, 255, 255);
        std::for_each(rq.begin(), rq.end(), [&](auto& snake_segment){
            SDL_RenderFillRect(renderer,&snake_segment);
        });

        SDL_RenderFillRect(renderer, &head);

        SDL_RenderPresent(renderer);
        SDL_Delay(25);
    }
    return 0;
}