Shmup kaktus

#include <stdlib.h>
#include <ctime>

#include "SDL/SDL.h"
#include "classes.h"

SDL_Surface *screen = NULL;
SDL_Surface *background = NULL;
SDL_Surface *ship = NULL;
SDL_Surface *astorider = NULL;

void quit();
void apply_surface(int x, int y, SDL_Surface* source, SDL_Surface* destination);
void move();
void game();
void astroider();

SDL_Event event;

//variabler
Uint8 *key;

int main(int argc, char *args []) {
    player.down = false;
    player.up = false;
    player.mid = true;
    player.Y = 240;

    SDL_Init(SDL_INIT_EVERYTHING);
    SDL_WM_SetCaption("Yeda - SHMUP", NULL);

    screen = SDL_SetVideoMode(640, 480, 32, SDL_SWSURFACE);
    background = SDL_LoadBMP("image/background.bmp");
    ship = SDL_LoadBMP("image/ship.bmp");
    astorider = SDL_LoadBMP("image/asteroids.bmp");

    apply_surface(0, 0, background, screen);
    apply_surface(0, player.Y, ship, screen);

    SDL_Flip(screen);

    game();

    SDL_Delay(2000);

    quit();
}

void quit() {
    SDL_FreeSurface(background);
    SDL_FreeSurface(ship);

    SDL_Quit();
}

void apply_surface(int x, int y, SDL_Surface* source, SDL_Surface* destination) {
    SDL_Rect offset;

    offset.x = x;
    offset.y = y;

    SDL_BlitSurface(source, NULL, destination, &offset);
}

void move() {
    if( SDL_PollEvent (&event)) {

            if(event.type == SDL_KEYDOWN) {

                switch(event.key.keysym.sym) {

                    case SDLK_DOWN:
                        //up
                        if(player.up == true) {
                            player.up = false;
                            player.mid = true;
                            player.Y = 240;
                        }

                        //mid
                        else if(player.mid == true) {
                            player.mid = false;
                            player.down = true;
                            player.Y = 280;
                        }
                        break;

                    case SDLK_UP:
                        //down
                        if(player.down == true) {
                            player.down = false;
                            player.mid = true;
                            player.Y = 240;
                        }

                        //mid
                        else if(player.mid == true) {
                            player.mid = false;
                            player.up = true;
                            player.Y = 200;
                        }
                        break;

                    case SDLK_ESCAPE:
                        quit();
                }
            }
        }
}

void game() {
    while(true) {
        apply_surface(0, 0, background, screen);
        apply_surface(0, player.Y, ship, screen);
        astroider();
        move();
        SDL_Flip(screen);
    }
}

void astroider() {
    srand(time(NULL));
    ast.X = 640;

    while(true) {
        ast.Y = rand() % ast.down + ast.mid + ast.up;
        ast.speed = rand() % 10 + 6;

        switch (ast.Y) {
            case ast.down:
                ast.Y = 280;
                break;

            case ast.mid:
                ast.y = 240;
                break;

            case ast.up:
                ast.Y = 200;
                break;
        }

        apply_surface(ast.X, ast.Y, astroider, screen);
    }

}