#define s_is_set(b) ((map&(1<<(b)))!=0) // checks if the b bit from the map is set to 1#define s_tog(b) (map^=(1<<(b))) // toggles the b bit of the map (currently not used)#define s_set_0(b) (map&=~(1<<b)) // sets to 0 the b bit from the map#define s_set_1(b) (map|=(1<<b)) // sets to 1 the b bit from the map

#define s_mask(start,len) (s_ls_bits(len)<<(start)) // creates a bitmask of len starting from position start#define s_prep(y,start,len) (((y)&s_ls_bits(len))<<(start)) // prepares the mask
// Gets the the 'len' number of bits, starting from position 'start' of 'y'#define s_get(y,start,len) (((y)>>(start))&s_ls_bits(len)) // Sets the the 'len' number of bits, starting from position 'start' of 'y' to the value 'bf'#define s_set(x,bf,start,len) (x=((x)&~s_mask(start,len))|s_prep(bf,start,len))
#define s_hpos s_get(vars,0,5) // gets the last 5 bits of 'vars', which corresponds to s_hpos#define s_tpos s_get(vars,5,5) // sets the last 5 bits of 'vars', which corresonds to s_hpos#define s_len s_get(vars,10,5)#define s_apos s_get(vars,15,5)#define s_chdir s_get(vars,20,2)#define s_hpos_set(pos) s_set(vars,pos,0,5)#define s_tpos_set(pos) s_set(vars,pos,5,5)#define s_len_set(len) s_set(vars,len,10,5)#define s_apos_set(app) s_set(vars,app,15,5)#define s_chdir_set(cdir) s_set(vars,cdir,20,2)#define s_len_inc s_len_set(s_len+1)

#define SU 0 //UP                       #define SD 1 //DOWN                  #define SL 2 //LEFT                #define SR 3 //RIGHT

#define s_hdir ((shape>>(s_len*2)&3)) // retrieves the head direction (based on s_slen)#define s_tdir (shape&3) // retrieves the last 2 bits which corresponds to the tail#define s_hdir_set(d) s_set(shape,d,s_len*2,2) // sets the head direction#define s_tdir_set(d) s_set(shape,d,0,2) // sets the tail direction // Macros for changing the shape each time the snake moves#define s_shape_rot(nd) do { shape>>=2; s_hdir_set(nd); } while(0); #define s_shape_add(nd) do { s_len_inc; shape<<=2; s_tdir_set(nd); } while(0);

// Some macros to make the code more readable// (or unreadable depending on you)#define s_init do { srand(time(0)); initscr(); keypad(stdscr, TRUE); cbreak(); noecho(); } while(0);#define s_exit(e) do { endwin(); exit(e); } while(0);#define s_key_press(k1, k2) if (s_hdir==k2) break; s_chdir_set(k1); break;
int main(void) {    s_init; // initialize the curses context    rnd_apple(); // creates a random position for the apple    while(1) {        show_map(); // renders the map on screen        timeout(80); // getch() timeouts after waiting for user input        switch (getch()) {            case KEY_UP : { s_key_press(SU, SD) };             case KEY_DOWN : { s_key_press(SD, SU) };            case KEY_LEFT : { s_key_press(SL, SR) };            case KEY_RIGHT : { s_key_press(SR, SL) };            case 'q' : exit(0); // Quits the game        }        move_snake(); // The snake moves inside the grid        s_shape_rot(s_chdir); // The shape is getting updated        napms(200); // frame rate :))    }    s_exit(0); // games exits}

#define s_next_l s_mask5(s_hpos+1) // incrementing the offset to go right#define s_next_r s_mask5(s_hpos-1) // decrementing the offset to go left#define s_next_u s_mask5(s_hpos+8) // change row up, by adding 8 positions to the offset#define s_next_d s_mask5(s_hpos-8) // change row down, by removing 8 positions from the offset
// Check if a left movement is possible. static void check_l() { if ((s_mod_p2(s_next_l,8) < s_mod_p2(s_hpos,8)) || s_is_set(s_next_l)) s_exit(-1); }// Check if a right movement is possible. static void check_r() { if ((s_mod_p2(s_next_r,8) > s_mod_p2(s_hpos,8)) || s_is_set(s_next_r)) s_exit(-1); }// Check if a up movement is possiblestatic void check_u() { if ((s_next_u < s_hpos) || s_is_set(s_next_u)) s_exit(-1); }// Check if a down movement is possiblestatic void check_d() { if ((s_next_d > s_hpos) || s_is_set(s_next_d)) s_exit(-1); }static void move_snake() {    if (s_hdir==SL) { check_l(); s_hpos_set(s_hpos+1); }     else if (s_hdir==SR) { check_r(); s_hpos_set(s_hpos-1); }     else if (s_hdir==SU) { check_u(); s_hpos_set(s_hpos+8); }    else if (s_hdir==SD) { check_d(); s_hpos_set(s_hpos-8); }    // Sets the bit based on the current s_hdir and s_hpos    s_set_1(s_hpos);    // If an apple is eaten    if (s_apos==s_hpos) {        // We generate another apple so we don't starve        rnd_apple();        // Append to the tail        s_shape_add(s_tdir);        // We stop clearning the tail bit        return;    }    // Clear the tail bit    s_set_0(s_tpos);    // Update the t_pos so we can clear the next tail bit when the snake moves    if (s_tdir==SL) { s_tpos_set(s_tpos+1); }     else if (s_tdir==SR) { s_tpos_set(s_tpos-1); }     else if (s_tdir==SU) { s_tpos_set(s_tpos+8); }     else if (s_tdir==SD) { s_tpos_set(s_tpos-8); }}

static void show_map() {    clear();    i=32;    while(i-->0) { // !! Trigger warning for sensitive people, incoming '-->0'        // If the bit is an apple, we render the apple '@'        if (i==s_apos) { addch('@'); addch(' '); }        // We draw either the snake bit ('#') or the empty bit ('.')        else { addch(s_is_set(i) ? '#':'.'); addch(' '); }        // We construct the grid by inserting a new line        if (!s_mod_p2(i,8)) { addch('\n'); }    };}

uint32_t map = 0x700;uint32_t vars = 0x20090a;uint64_t shape = 0x2a;int8_t i = 0;static void rnd_apple() {    i = (rand()&(32 -1));    while(((map&(1<<(i)))!=0)) i = (rand()&(32 -1));    (vars=((vars)&~(((1<<(5))-1)<<(15)))|(((i)&((1<<(5))-1))<<(15)));}static void show_map() {    wclear(stdscr);    i=32;    while(i-->0) {        if (i==(((vars)>>(15))&((1<<(5))-1))) { waddch(stdscr,'@'); waddch(stdscr,' '); }        else { waddch(stdscr,((map&(1<<(i)))!=0) ? '#':'.'); waddch(stdscr,' '); }        if (!(i&(8 -1))) { waddch(stdscr,'\n'); }    };}static void check_l() { if ((((((((vars)>>(0))&((1<<(5))-1))+1)&0x1f)&(8 -1)) < ((((vars)>>(0))&((1<<(5))-1))&(8 -1))) || ((map&(1<<((((((vars)>>(0))&((1<<(5))-1))+1)&0x1f))))!=0)) do { endwin(); exit(-1); } while(0);; }static void check_r() { if ((((((((vars)>>(0))&((1<<(5))-1))-1)&0x1f)&(8 -1)) > ((((vars)>>(0))&((1<<(5))-1))&(8 -1))) || ((map&(1<<((((((vars)>>(0))&((1<<(5))-1))-1)&0x1f))))!=0)) do { endwin(); exit(-1); } while(0);; }static void check_u() { if (((((((vars)>>(0))&((1<<(5))-1))+8)&0x1f) < (((vars)>>(0))&((1<<(5))-1))) || ((map&(1<<((((((vars)>>(0))&((1<<(5))-1))+8)&0x1f))))!=0)) do { endwin(); exit(-1); } while(0);; }static void check_d() { if (((((((vars)>>(0))&((1<<(5))-1))-8)&0x1f) > (((vars)>>(0))&((1<<(5))-1))) || ((map&(1<<((((((vars)>>(0))&((1<<(5))-1))-8)&0x1f))))!=0)) do { endwin(); exit(-1); } while(0);; }static void move_snake() {    if (((shape>>((((vars)>>(10))&((1<<(5))-1))*2)&3))==2) { check_l(); (vars=((vars)&~(((1<<(5))-1)<<(0)))|((((((vars)>>(0))&((1<<(5))-1))+1)&((1<<(5))-1))<<(0))); }    else if (((shape>>((((vars)>>(10))&((1<<(5))-1))*2)&3))==3) { check_r(); (vars=((vars)&~(((1<<(5))-1)<<(0)))|((((((vars)>>(0))&((1<<(5))-1))-1)&((1<<(5))-1))<<(0))); }    else if (((shape>>((((vars)>>(10))&((1<<(5))-1))*2)&3))==0) { check_u(); (vars=((vars)&~(((1<<(5))-1)<<(0)))|((((((vars)>>(0))&((1<<(5))-1))+8)&((1<<(5))-1))<<(0))); }    else if (((shape>>((((vars)>>(10))&((1<<(5))-1))*2)&3))==1) { check_d(); (vars=((vars)&~(((1<<(5))-1)<<(0)))|((((((vars)>>(0))&((1<<(5))-1))-8)&((1<<(5))-1))<<(0))); }    (map|=(1<<(((vars)>>(0))&((1<<(5))-1))));    if ((((vars)>>(15))&((1<<(5))-1))==(((vars)>>(0))&((1<<(5))-1))) {        rnd_apple();        do { (vars=((vars)&~(((1<<(5))-1)<<(10)))|((((((vars)>>(10))&((1<<(5))-1))+1)&((1<<(5))-1))<<(10))); shape<<=2; (shape=((shape)&~(((1<<(2))-1)<<(0)))|((((shape&3))&((1<<(2))-1))<<(0))); } while(0);;        return;    }    (map&=~(1<<(((vars)>>(5))&((1<<(5))-1))));    if ((shape&3)==2) { (vars=((vars)&~(((1<<(5))-1)<<(5)))|((((((vars)>>(5))&((1<<(5))-1))+1)&((1<<(5))-1))<<(5))); }    else if ((shape&3)==3) { (vars=((vars)&~(((1<<(5))-1)<<(5)))|((((((vars)>>(5))&((1<<(5))-1))-1)&((1<<(5))-1))<<(5))); }    else if ((shape&3)==0) { (vars=((vars)&~(((1<<(5))-1)<<(5)))|((((((vars)>>(5))&((1<<(5))-1))+8)&((1<<(5))-1))<<(5))); }    else if ((shape&3)==1) { (vars=((vars)&~(((1<<(5))-1)<<(5)))|((((((vars)>>(5))&((1<<(5))-1))-8)&((1<<(5))-1))<<(5))); }}

int main(void) {    do { srand(time(0)); initscr(); keypad(stdscr, 1); cbreak(); noecho(); } while(0);;    rnd_apple();    while(1) {        show_map();        wtimeout(stdscr,80);        switch (wgetch(stdscr)) {            case 0403 : { if (((shape>>((((vars)>>(10))&((1<<(5))-1))*2)&3))==1) break; (vars=((vars)&~(((1<<(2))-1)<<(20)))|(((0)&((1<<(2))-1))<<(20))); break; };            case 0402 : { if (((shape>>((((vars)>>(10))&((1<<(5))-1))*2)&3))==0) break; (vars=((vars)&~(((1<<(2))-1)<<(20)))|(((1)&((1<<(2))-1))<<(20))); break; };            case 0404 : { if (((shape>>((((vars)>>(10))&((1<<(5))-1))*2)&3))==3) break; (vars=((vars)&~(((1<<(2))-1)<<(20)))|(((2)&((1<<(2))-1))<<(20))); break; };            case 0405 : { if (((shape>>((((vars)>>(10))&((1<<(5))-1))*2)&3))==2) break; (vars=((vars)&~(((1<<(2))-1)<<(20)))|(((3)&((1<<(2))-1))<<(20))); break; };            case 'q' : exit(0);        }        move_snake();        do { shape>>=2; (shape=((shape)&~(((1<<(2))-1)<<((((vars)>>(10))&((1<<(5))-1))*2)))|((((((vars)>>(20))&((1<<(2))-1)))&((1<<(2))-1))<<((((vars)>>(10))&((1<<(5))-1))*2))); } while(0);;        napms(200);    }    do { endwin(); exit(0); } while(0);;}