Simple game using Data Structures

[aruljothi]

Code :
# include <stdio.h>
# include <conio.h>
# include <graphics.h>
# include <alloc.h>
# include <dos.h>
# include <stdlib.h>
# define up 72
# define down 80
# define left 75
# define right 77
# define pause 25
# define space 57
# define settings 31
struct body
{
int x,y;
struct body *next;
};
typedef struct body body;
void create_snake(body*);
void show_settings();
void draw_borders();
void draw_egg();
void draw_snake();
void status_bar();
void draw_head();
void erase_tail();
void disp_gameover();
int getkey();
int check_snake(int,int);
body *head,*tail;
int dir=1;
int speed=100;
int leftx,rightx,topx,bottomx;
int color = RED,fil_style=1,bor_color=BLACK,size = 10;
int score=0,egg_drawn=0,jump = 9;
int preveggx,preveggy;
void far *egg;
char scr[15];
int eggx,eggy;
void main()
{
int gm=DETECT,gd;
int key=0,num;
struct time tim;
void move_snake_right();
void move_snake_down();
void move_snake_left();
void move_snake_up();
initgraph(&gm,&gm,"g:\tc\bgi");
leftx=(size*2-1);
rightx=getmaxx()-(size*2);
topx=(size*2-1);
bottomx = getmaxy()-40;
setcolor(YELLOW);
setfillstyle(SOLID_FILL,YELLOW);
fillellipse(10,10,size/3,size/2);
egg = farmalloc(imagesize(10-size/2,10-size/2,10+size/2,10+size/2));
if(egg ==NULL)
{
  printf("Insufficient Memory!");
  exit(0);
}
getimage(10-size/2,10-size/2,10+size/2,10+size/2,egg);
draw_borders();
create_snake(head);
start:
fflush(stdin);
flushall();
while(!kbhit())
{
delay(speed);
if(egg_drawn==0)
{
  status_bar();
  eggx=eggy=0;
  repeat:
  gettime(&tim);
  num = (int)(tim.ti_hund)*(int)(tim.ti_sec);
  num = num%(rightx-leftx)/size;
  eggx=num;
  num = (int)(tim.ti_hund)*(int)tim.ti_sec;
  num = num%(bottomx-topx)/size;
  eggy=num;
   if(check_snake(eggx,eggy))
   goto repeat;
  eggx =leftx+(eggx*size);
  eggy =topx+(eggy*size);
  preveggx =leftx+(eggx*size);
  preveggy =topx+(eggy*size);
}
draw_egg(eggx,eggy);
  switch(dir)
  {
   case 1:move_snake_right();
     break;
   case 2:move_snake_down();
     break;
   case 3:move_snake_left();
     break;
   case 4:move_snake_up();
  }
}
key = getkey();
switch(key)
{
  case up:if(dir!=2)
     dir = 4;
     break;
  case down:if(dir!=4)
      dir = 2;
      break;
  case right:if(dir!=3)
        dir = 1;
        break;
  case left:if(dir!=1)
       dir = 3;
       break;
  case pause:getch();
       break;
  case settings:show_settings();
      setfillstyle(EMPTY_FILL,color);
      bar(leftx,topx,rightx,bottomx);
      draw_snake();
      break;
  case 1:closegraph();
    exit(0);
}
goto start;
}
int getkey()
{
union REGS i,o;
i.h.ah = 0;
int86(0x16,&i,&o);
return o.h.ah;
}
void draw_borders()
{
  setfillstyle(SOLID_FILL,BLUE);
  floodfill(300,300,1);
  setfillstyle(SOLID_FILL,BLACK);
  setcolor(BLACK);
  rectangle(leftx,topx,rightx,bottomx);
  setfillstyle(SOLID_FILL,BLACK);
  floodfill(300,300,BLACK);
  rectangle(leftx,bottomx+5,rightx,getmaxy()-5);
}
void create_snake()
{
body *x;
setfillstyle(fil_style,color);
setcolor(bor_color);
if((x = malloc(sizeof(body)))==NULL)
{
  printf("Short of memory!");
  return;
}
x->x = size*3+leftx;
x->y = topx;
head = x;
bar(x->x,x->y,x->x+size,x->y+size);
rectangle(x->x,x->y,x->x+size,x->y+size);
if((x->next = malloc(sizeof(body)))==NULL)
{
  printf("Short of memory!");
  return;
}
x = x->next;
x->x = size*2+leftx;
x->y = topx;
bar(x->x,x->y,x->x+size,x->y+size);
rectangle(x->x,x->y,x->x+size,x->y+size);
if((x->next = malloc(sizeof(body)))==NULL)
{
  printf("Short of memory!");
  return;
}
x = x->next;
x->x = size+leftx;
x->y = topx;
bar(x->x,x->y,x->x+size,x->y+size);
rectangle(x->x,x->y,x->x+size,x->y+size);
if((x->next = malloc(sizeof(body)))==NULL)
{
  printf("Short of memory!");
  return;
}
x = x->next;
x->x = leftx;
x->y = topx;
bar(x->x,x->y,x->x+size,x->y+size);
rectangle(x->x,x->y,x->x+size,x->y+size);
x->next = NULL;
tail = x;
}
void move_snake_right()
{
body *x;
int nextx,nexty;
nexty = head->y;
if(head->x+size>=rightx)
  nextx = leftx;
else
  nextx = head->x+size;
if(check_snake(nextx,nexty)==1)
  {
   disp_gameover();
  }
if(nextx == eggx&&nexty == eggy)
{
  egg_drawn=0;
  score+=jump;
  x = malloc(sizeof(body));
  if(x==NULL)
  {
   printf("Insufficient Memory!");
   exit(0);
  }
  x->x = nextx;
  x->y = nexty;
  x->next = head;
  head = x;
  draw_head();
}
else
  {
   erase_tail();
   x = head;
   while((x->next)->next !=NULL)
   x = x->next;
   x->next = NULL;
   tail->x = nextx;
   tail->y = nexty;
   tail->next = head;
   head = tail;
   tail = x;
   draw_head();
  }
}
void move_snake_left()
{
body *x;
int nextx,nexty;
if(head->x-size<leftx)
  nextx = rightx-size;
else
  nextx = head->x-size;
nexty = head->y;
if(check_snake(nextx,nexty)==1)
  {
   disp_gameover();
  }
if(nextx==eggx&&nexty==eggy)
{
  egg_drawn=0;
  score+=jump;
  x = malloc(sizeof(body));
  if(x==NULL)
  {
   printf("Insufficient Memory!");
   exit(0);
  }
  x->x = nextx;
  x->y = nexty;
  x->next = head;
  head = x;
  draw_head();
}
else
  {
   erase_tail();
   x = head;
   while((x->next)->next !=NULL)
   x = x->next;
   x->next = NULL;
   tail->x = nextx;
   tail->y = nexty;
   tail->next = head;
   head = tail;
   tail = x;
   draw_head();
  }

}
void move_snake_up()
{
body *x;
int nextx,nexty;
if(head->y-size<topx)
  nexty = bottomx-size;
else
  nexty = head->y-size;
nextx = head->x;
if(check_snake(nextx,nexty)==1)
  {
   disp_gameover();
  }
if(nextx==eggx&&nexty==eggy)
{
  egg_drawn=0;
  score+=jump;
  x = malloc(sizeof(body));
  if(x==NULL)
  {
   printf("Insufficient Memory!");
   exit(0);
  }
  x->x = nextx;
  x->y = nexty;
  x->next = head;
  head = x;
  draw_head();
}
else
  {
   erase_tail();
   x = head;
   while((x->next)->next !=NULL)
   x = x->next;
   x->next = NULL;
   tail->x = nextx;
   tail->y = nexty;
   tail->next = head;
   head = tail;
   tail = x;
   draw_head();
  }
}
void move_snake_down()
{
body *x;
int nextx,nexty;
if(head->y+size>=bottomx)
  nexty = topx;
else
  nexty = head->y+size;
nextx = head->x;
if(check_snake(nextx,nexty)==1)
  {
   disp_gameover();
  }
if(nextx==eggx&&nexty==eggy)
{
  egg_drawn=0;
  score+=jump;
  x = malloc(sizeof(body));
  if(x==NULL)
  {
   printf("Insufficient Memory!");
   exit(0);
  }
  x->x = nextx;
  x->y = nexty;
  x->next = head;
  head = x;
  draw_head();
}
else
  {
   erase_tail();
   x = head;
   while((x->next)->next !=NULL)
   x = x->next;
   x->next = NULL;
   tail->x = nextx;
   tail->y = nexty;
   tail->next = head;
   head = tail;
   tail = x;
   draw_head();
  }

}
void draw_egg(int x,int y)
{
putimage(x,y,egg,COPY_PUT);
egg_drawn = 1;
}

void status_bar()
{
  setfillstyle(SOLID_FILL,LIGHTGRAY);
  bar(leftx+1,bottomx+4,rightx-1,getmaxy()-6);
  sprintf(scr,"Score:%d",score);
  setcolor(RED);
  settextstyle(2,0,6);
  outtextxy(leftx+5,bottomx+10,scr);
  outtextxy(rightx-75,bottomx+10,"S");
  setcolor(DARKGRAY);
  outtextxy(rightx-66,bottomx+10,"ettings");
  setcolor(RED);
  outtextxy(rightx-150,bottomx+10,"P");
  setcolor(DARKGRAY);
  outtextxy(rightx-142,bottomx+10,"ause");
}
void draw_head()
{
setfillstyle(fil_style,color);
bar(head->x,head->y,head->x+size,head->y+size);
setcolor(bor_color);
rectangle(head->x,head->y,head->x+size,head->y+size);
}
void erase_tail()
{
setfillstyle(EMPTY_FILL,color);
bar(tail->x,tail->y,tail->x+size,tail->y+size);
}
int check_snake(int x,int y)
{
body *z;
z = head;
while(z->next!=NULL)
{
  if(z->x==x&&z->y==y)
   return 1;
  z=z->next;
}
  if(z->x==x&&z->y==y)
   return 1;
  return 0;
}
void disp_gameover()
{
int x1,x2,y1,y2;
x1 = getmaxx()/2-100;
y1 = getmaxy()/2-65;
x2 = getmaxx()/2+100;
y2 = getmaxy()/2+65;
setfillstyle(SOLID_FILL,9);
bar(x1,y1,x2-30,y2-75);
setcolor(YELLOW);
settextstyle(3,0,3);
outtextxy(x1+10,y1+10,"GAME OVER!!");
getch();
closegraph();
exit(0);
}
void show_settings()
{
int key=0,maxspeed=25,least = 145;
int x1,y1,x2,y2,width;
int no,i;
setfillstyle(SOLID_FILL,LIGHTGRAY);
x1 = (getmaxx()+1)/2-150;
x2 = (getmaxx()+1)/2+150;
y1 = (getmaxy()+1)/2-150;
y2 = (getmaxy()+1)/2+150;
setcolor(BLUE);
bar3d(x1,y1,x2,y2,20,1);
settextstyle(2,0,6);
setcolor(RED);
outtextxy(x1+20,y1+100,"Speed:");
outtextxy(x1+85,y1+95,"-");
outtextxy(x2-10,y1+95,"+");
outtextxy(x1+20,y1+150," Use the left and right");
outtextxy(x1+20,y1+180,"arrow keys to increase and ");
outtextxy(x1+20,y1+210,"  decrease the speed ");
outtextxy(x1+20,y1+240,"Press escape to return");
outtextxy(x1+20,y1+270,"    to the game");
setcolor(BLUE);
line(x1+100,y1+120,x2-20,y1+120);
line(x1+100,y1+120,x1+100,y1+90);
line(x2-20,y1+120,x2-20,y1+90);
width = ((x2-20)-(x1+100))/8;
start:
setfillstyle(SOLID_FILL,LIGHTGRAY);
for(i=1;i<=no;i++)
{
  bar(x1+100+1,y1+90+1,x1+100+(i*width)-1,y1+120-1);
  setcolor(LIGHTGRAY);
  rectangle(x1+100+1,y1+90+1,x1+100+(i*width)-1,y1+120-1);
}
no = (speed-25)/15;
setfillstyle(SOLID_FILL,BLUE);
for(i=1;i<=no;i++)
{
  bar(x1+100+1,y1+90+1,x1+100+(i*width)-1,y1+120-1);
  setcolor(LIGHTGRAY);
  rectangle(x1+100+1,y1+90+1,x1+100+(i*width)-1,y1+120-1);
}
def:
key = getkey();
switch(key)
{
  case right:if(speed<least)
        speed+=15;
        goto start;
  case left:if(speed>maxspeed)
       speed-=25;
        goto start;
  case 1:return;
  default:goto def;
}
}
void draw_snake()
{
body *x;
x = head;
setfillstyle(SOLID_FILL,color);
setcolor(bor_color);
while(x->next!=NULL)
{
  bar(x->x,x->y,x->x+size,x->y+size);
  rectangle(x->x,x->y,x->x+size,x->y+size);
  x = x->next;
}
}