#include <SDL2/SDL.h>

struct ARGB
{
    Uint8 b, g, r, a;
};

int main(int argc, char *argv[])
{
    SDL_Init(SDL_INIT_EVERYTHING);

    SDL_Window *w = SDL_CreateWindow("pixels", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 640, 480, SDL_WINDOW_SHOWN);
    SDL_Renderer *r = SDL_CreateRenderer(w, -1, 0);
    SDL_RenderSetLogicalSize(r, 320, 240);
    SDL_Texture *t = SDL_CreateTexture(r, SDL_PIXELFORMAT_ARGB8888, SDL_TEXTUREACCESS_STREAMING, 320, 240);

    ARGB *pixels;
    int pitch;

    SDL_Event sdlEvent;
    bool exit = false;
    while (!exit)
    {
        while (SDL_PollEvent(&sdlEvent))
        {
            if (sdlEvent.type == SDL_QUIT)
            {
                exit = true;
                break;
            }
        }

        SDL_LockTexture(t, nullptr, (void **)&pixels, &pitch);

        for (int i = 0; i < 76800; ++i)
        {
            pixels[i].b = rand() % 256;
            pixels[i].g = rand() % 256;
            pixels[i].r = rand() % 256;
            pixels[i].a = 255;
        }

        SDL_UnlockTexture(t);

        SDL_RenderCopy(r, t, nullptr, nullptr);

        SDL_RenderPresent(r);
    }
}