Keeper - A two player game in C

This is tutorial for creating a Two player game in C.

The name of game is keeper. It is very simple game and very easy to implement. Even if you are novice to Graphics programming in c, you will be able to grasp everything.

Download Source code from  Here





Required Structures :

• pad : This structure will keep track of location of pad and size of pad. 
• ball : This structure will keep track of ball size, position and direction of ball
• limit : This structure consist the coordinates of boundary of  game area.
• game_data : This structure will keep track of score.

struct pad
{
int x,y,l;
}pd1={100,200,30},pd2={440,200,30};

struct game_data
{
int score;
};
struct game_data p1={0},p2={0};

struct limit
{
int lx1,ly1,lx2,ly2;
};
struct limit l={90,90,450,400};

struct ball
{
int x,y;
int dir;
int size;
}ball={250,250,7,5};

There are several functions like game,draw, get_dir, mv_ball  etc.. all of them are self explainatory. comments are provided in the source code.

draw function will draw whole screen including boundaries, ball, pads.

draw(void)
{

rectangle(l.lx1,l.ly1,l.lx2,l.ly2);
circle(ball.x,ball.y,ball.size);
rectangle(pd1.x-5,pd1.y-30,pd1.x+5,pd1.y+30);
rectangle(pd2.x-5,pd2.y-30,pd2.x+5,pd2.y+30);
delay(15);
while(!kbhit()){goto e;}
k=getche();
if(k=='w' || k=='s'||k=='e'){key1=k;}
else if(k==72||k==80||k==77||k=='o'){key2=k;}
e:
cleardevice();

}

mv_ball will provide new coordinates of ball according to it's direction

void mv_ball(void)
{
switch(ball.dir)
{
case 0 : ball.y-=2; break;
case 8 : ball.y+=2; break;
case 2 : ball.x+=2; break;
case 6 : ball.x-=2; break;
case 1 : ball.x+=2; ball.y-=2; break;
case 3 : ball.x-=2; ball.y+=2; break;
case 7 : ball.x+=2; ball.y+=2; break;
case 5 : ball.x-=2; ball.y-=2; break;
}
}

game function is main function for game logic. It will check that whether ball hits boundary, pad , any key is pressed or not etc...

void game(void)
{
draw();
while(1)
{
      if(ball.y-l.ly1<=ball.size||l.ly2-ball.y<ball.size)
      {
        d=0;
        get_dir();
      }

      if((ball.x-105<=ball.size && abs(ball.y-pd1.y)<=32 )||(435-ball.x<=ball.size&& abs(ball.y-pd2.y)<=32))
      {
        d=1;
        get_dir();
      }



if(ball.x<l.lx1||l.lx2<ball.x)
{

if(ball.x<l.lx1)
{p2.score=p2.score+100;}
else
{p1.score=p1.score+100;}

ball.x=250;//+random(245);
ball.y=150;//+random(245);
pd1.y=250;
pd2.y=250;
      // ball.dir=random(7);
while(!kbhit()){ draw();}

}

sswitch(key1)
{
 case 'w':   if(pd1.y-pd1.l-l.ly1>10) pd1.y-=2;  break;
 case 's':   if(l.ly2-(pd1.y+pd1.l)>10) pd1.y+=2;  break;
 default : break;
}
switch(key2)
{
 case 72:    if(pd2.y-pd2.l-l.ly1>10) pd2.y-=2;  break;
 case 80:    if(l.ly2-(pd2.y+pd2.l)>10) pd2.y+=2;  break;
 case 'o' : gameover();
 default  : break;
}


      draw();

      mv_ball();


   }

}

When 'o' is pressed ,The game will be over and score of each player will be displayed.

If you have any query or suggestion then leave comment !