[Code Tutorial]Non-Actor Flame Walls

Well, here's my first big tutorial, so there's bound to be mistakes It comes from my project source, so if you have any problems let me know and I'll try to fix it. I said flame wall, but really it is just using the rocket, you'll have to add your own flame projectile. Some credit goes to Wolf3DBreaker, as I used a modified portion of his code for player shooting projectiles in the T_Projectile function (so it will kill guards).

It uses an object to spawn rockets at set intervals rather than the actor concept I've already seen on these forums. Hopefully this runs alot faster and takes less memory & data bytes.. Also note that I haven't made the switch to turn it off yet, I'll update the tut when I do. Also, you can have as many as you want, however they all currently shoot EAST.

Okay, here we go. First we'll need to add a new flag, so open up "WL_DEF.H". Look for this code, near the top, and add the red line:

Code:


#define FL_SHOOTABLE   1
#define FL_BONUS      2
#define FL_NEVERMARK   4
#define FL_VISABLE      8
#define FL_ATTACKMODE   16
#define FL_FIRSTATTACK   32
#define FL_AMBUSH      64
#define FL_NONMARK      128
[color=red]#define FL_KILLALL   16[/color]

Next, go to the gamestate structure, and add this:

Code:

   
int         ammo;
int         keys;
weapontype      bestweapon,weapon,chosenweapon,nextweapon;

[color=red]boolean       firewall;[/color]

Close that file, and open "WL_PLAY.C". The majority of the code is here. Scroll down to the play loop function (at the very bottom) and add the red lines:

Code:

/*
===================
=
= PlayLoop
=
===================
*/
long funnyticount;
[color=red]long fireticount;[/color]


void PlayLoop (void)
{
   int      give;
   int   helmetangle;

   playstate = TimeCount = lasttimecount = 0;
   frameon = 0;
   running = false;
   anglefrac = 0;
   facecount = 0;
   funnyticount = 0;
   memset (buttonstate,0,sizeof(buttonstate));
   ClearPaletteShifts ();

   if (MousePresent)
      Mouse(MDelta);   // Clear accumulated mouse movement

   if (demoplayback)
      IN_StartAck ();

   do
   {
      if (virtualreality)
      {
         helmetangle = peek (0x40,0xf0);
         player->angle += helmetangle;
         if (player->angle >= ANGLES)
            player->angle -= ANGLES;
      }


      PollControls();

//
// actor thinking
//
      madenoise = false;

      MoveDoors ();
      MovePWalls ();

      for (obj = player;obj;obj = obj->next)
         DoActor (obj);

      UpdatePaletteShifts ();

      ThreeDRefresh ();

      //
      // MAKE FUNNY FACE IF BJ DOESN'T MOVE FOR AWHILE
      //
      #ifdef SPEAR
      funnyticount += tics;
      if (funnyticount > 30l*70)
      {
         funnyticount = 0;
         StatusDrawPic (17,4,BJWAITING1PIC+(US_RndT()&1));
         facecount = 0;
      }
      #endif
[color=red]
      fireticount+=tics;
      if (fireticount>100)
         {
         FireScan();
         fireticount=0;
         }
[/color]

rest of function skipped...

Now, at the very bottom of the file, add this:

Code:

[color=red]
/*
===================
=
= Scan for Firewall
=
===================
*/

#define FireObject 600

extern   statetype s_rocket; //For Fire Wall

void FireScan (void)
{
int x,y,tile;

if (gamestate.firewall==true) //No sense scanning if it isn't on
   {
   for (y=0;y<mapheight;y++)
      for (x=0;x<mapwidth;x++)
      {
         tile=MAPSPOT(x,y,1);
         if (tile==FireObject)
         {
         GetNewActor ();
         new->state = &s_rocket;
         new->ticcount = 1;

         new->tilex = x;
         new->tiley = y;
         //new->x = ob->x;
         //new->y = ob->y;
         new->x = ((long)x<<TILESHIFT)+TILEGLOBAL/2;
         new->y = ((long)y<<TILESHIFT)+TILEGLOBAL/2;
         new->obclass = rocketobj;
         new->dir = nodir;
         new->angle = 0;
         new->speed = 0x2000l;
         new->flags = FL_NONMARK | FL_KILLALL;
         new->active = true;
         }
            
            
      }
   }

}[/color]

FireObject is whatever object you want to spawn the fire. You could modify this to include multible objects for diffrent directions.

Now close that file, and open up "WL_ACT2.C". Go to the T_Projectile function, and add the red lines:

Code:


      // Check if player hit by anything

[color=red]
   if (ob->obclass == rocketobj && ob->flags & FL_NONMARK && ob->flags & FL_KILLALL)
      {
       check = objlist ;
         while (check)
         {
        if (check->flags & FL_SHOOTABLE)
        {
            deltax = LABS(ob->x - check->x);
            deltay = LABS(ob->y - check->y);

            if (deltax < PROJECTILESIZE && deltay < PROJECTILESIZE)
            {
              //if (check->obclass != angelobj)
                      //  PlaySoundLocActor(MISSILEHITSND,ob);
              ob->state = &s_boom1;     
              damage = (US_RndT() >>3) + 30;
              DamageActor (check,damage);
             
            }
        }
        check = check->next ;
      }
    }   [/color]

      deltax = LABS(ob->x - player->x);
      deltay = LABS(ob->y - player->y);

      if (deltax < PROJECTILESIZE && deltay < PROJECTILESIZE)
      {  // hit the player
        switch (ob->obclass)
        {
        case needleobj:
            damage = (US_RndT() >>3) + 20;
            break;
        case rocketobj:
        case hrocketobj:
            //  case sparkobj:
            damage = (US_RndT() >>3) + 30;
            break;

rest of code not included...

Close that file. Now, I'm assuming you'll want the firewalls to come on every level if you add a switch to turn them off...simple. Open up "WL_INTER.C". In the PreloadGraphics function, add this:

Code:


   LatchDrawPic (20-14,80-3*8,GETPSYCHEDPIC);

   WindowX = 160-14*8;
   WindowY = 80-3*8;
   WindowW = 28*8;
   WindowH = 48;
   VW_UpdateScreen();
   VW_FadeIn ();

   PM_Preload (PreloadUpdate);
   IN_UserInput (70);
   VW_FadeOut ();

   DrawPlayBorder ();
   VW_UpdateScreen ();

   [color=red]//Update Variables
   gamestate.firewall=true;[/color]
}


Ta da! Now place object 600 in your favorite map editor (preferably in front of a wall) and watch rockets fly from it! I'll add the code for the switch later. Remeber to give credit, and please report any bugs!

EDIT: Seems red doesn't work in code boxes like on DHW. Well, just add what's between the [color] boxes, don't actually add those

interesting, like in eod.
how much damage does it do? 1 hit ko?

It does the same damage as rockets.

Good Stuff Airslide!

in the eod it is 1 hit ko, although rokets are fine.

Just FYI, updated tut is here:
http://diehardwolfers.areyep.com/viewtopic.php?t=4487
Didn't feel like updating the one above, and it should be easier to read on DHW.