[/code]
#include <acknex.h>
#include <default.c>
//
#define MODE_STAND  0
#define MODE_WALK   1
#define MODE_RUN    2
#define MODE_DEATH  3
#define MODE_ATTACK 4
#define MODE_STOP   5
#define MODE_MARCH  6
#define MODE_STANDBY 7

STRING* buff = "          ";
static int NPC_Counter = 0;

typedef struct
{
	var health;
	var shield;
	var count;
	var state;
	var pathnode;
	var lin_speed;
	var rot_speed;
	var anim_speed;
	var vision_range;
	var weapon_type;
	var weapon;
	var weapon_range;
	var ammo;
	ENTITY* model;
} entity3d; 

function act_player(entity3d* ent);
function all_events(); 
function check_downward(entity3d* ent, vmin, vmax);
function act_enemy(entity3d* ent);


function main()
{
   level_load(NULL);  // load the game level
   entity3d hero;
   hero.model = ent_create ("player.mdl", vector(0,0,0), NULL);
   act_player(hero);
   NPC_Counter++;

   entity3d enemy;
   enemy.model = ent_create ("player.mdl", vector(40,40,0), NULL);
   act_enemy(enemy);
   NPC_Counter++;
}


function act_player(entity3d* ent)
{
   ent.state = MODE_WALK;
   ent.health = 100;
   ent.vision_range = 200;
   ent.lin_speed = 5;
   ent.rot_speed = 1;
   ent.model.scale_x = .5;
   ent.model.scale_y = .5;
   ent.model.scale_z = .5;
   ent.model.emask |= (ENABLE_BLOCK | ENABLE_ENTITY | ENABLE_IMPACT);
   ent.model.event = all_events;
   //set(ent.model, INVISIBLE);
   player = my = ent.model;
   
   while(1)
   {
     camera.x = my.x;
     camera.y = my.y;
     camera.z = my.z + 5;
     camera.pan = my.pan;
     camera.tilt = my.tilt;

     move_mode = IGNORE_PASSABLE + USE_BOX;  
     // movement keys 'WASD' 
     if(key_w == 1)
     { 
        ent_move (vector(5 * time_step,0,0), nullvector);
        // little up-down movement while walking
        my.z += .5 * sin(total_ticks * 25) * time_step;
        // if inclined, get straight while walking 
        if(my.tilt < 1) my.tilt += .25;
        if(my.tilt > 1) my.tilt -= .25;
     }
     
     if(key_s == 1)
     {
     	  ent_move (vector(-5 * time_step,0,0), nullvector);

        if(my.tilt < 1) 
           my.tilt += .25;

        if(my.tilt > 1) 
           my.tilt -= .25;
     }

     if(key_a == 1) 
        my.pan += 3 * time_step;
     
     if(key_d == 1)
        my.pan -= 3 * time_step;
     
     if(key_q == 1)  // do not allow more than 30 deg inclination
     { 
       if(my.tilt > 30)
          my.tilt = 30;
          
       my.tilt += 1;
     }

     if(key_z == 1) // do not allow more than 30 deg inclination
     {
     	 if(my.tilt < -30)
     	    my.tilt = -30;
     	 
     	 my.tilt -= 1;
     }
    
     check_downward(&ent, 0, 3);

     wait(1);
  }

}

function check_downward(entity3d* ent, vmin, vmax)
{
    proc_kill(4);
    var dist_trace;
    VECTOR temp;
    
    // check downward 
    vec_set (temp.x, ent.model.x);
    temp.z = ent.model.z - 15000;
    trace_mode = IGNORE_ME + IGNORE_SPRITES + USE_BOX + IGNORE_PASSABLE;
    dist_trace = trace (ent.model.x, temp.x);

    // stay above ground
    if(dist_trace < vmin)
       ent.model.z += 1; 

    if(dist_trace > vmax)
       ent.model.z -= 1;

    if(dist_trace > (vmax + 5))
       ent.model.z -= 3;

    if(dist_trace < (vmin - 4))
       ent.model.z += 3;   

}

function act_enemy(entity3d* ent)
{
  var percent;
  var d1;
  var d2;
  var vmin = 0;
  var vmax = 3;
  VECTOR temp;
  var dist_trace;

  my = ent.model;
  my.scale_x = .4;
  my.scale_y = .4;
  my.scale_z = .4;
      
  while(!player){wait(1);}

  ent.state = MODE_WALK;       	

  ent.health = 100;
  ent.vision_range = 250;
  
  while(ent.health > 10)
  {
     d1 = vec_dist(ent.model.x, player.x);

    if (ent.state == MODE_WALK)
    {
       percent += 3 * time_step;
       ent_animate(ent.model,"walk", percent, ANM_CYCLE);
       percent %= 100;
    }
    

    if (ent.state == MODE_ATTACK)
    {
       vec_set(temp,my.x);
       if(vec_dist(me.x, player.x)<1000 && vec_to_screen(temp,camera)!=NULL)
       {
           str_for_num(buff, ent.health);
 	   draw_text(buff, temp.x, temp.y-20, vector(200,200,200));
       }
       // perform animation
       percent += 3 * time_step;
       ent_animate(my,"attack", percent, ANM_CYCLE);
       percent %= 100;
       // rotate to the target
       vec_set(temp,player.x); 
       vec_sub(temp,my.x);
       vec_to_angle(my.pan,temp); // now MY looks at YOU
    }   

    // traced something in range AND is the player
    if((c_trace (my.x, player.x, IGNORE_ME | IGNORE_PASSABLE) < ent.vision_range) && (you == player))
    {  
       d2 = vec_dist(my.x,player.x);
       //im moving toward the player
       if((d2 <= d1) && ( ent.health > 30))
       {         	
          ent.state = MODE_ATTACK;
       }
    }
    else
    {
       ent.state = MODE_WALK;
    }    
    
    wait(1);
    
    check_downward(&ent, vmin, vmax);

  }
}

function all_events() 
{
  switch (event_type)
  {
    case EVENT_BLOCK:
      
      return;
    
    case EVENT_ENTITY: 
    
      return;
  }
}  
[code]