...
var idx;   for(idx=0; idx<Top_obj; idx++)
...

#include <acknex.h>
#include <default.c>

var num_boxes = 0;
var num_fragments = 0;

d3d_alpharef = 180;


ENTITY* Objects[10000];
#define otype       skill20      //0=bomb 1=fragment
#define velx        skill21
#define vely        skill22
#define velz        skill23
#define lifetime    skill25      
//#define ????????  skill26      
//#define ????????  skill27      
var Top_obj=1;      //'current' highest used index for optimising main-loop check



PANEL* panDisplay =
{
   digits(535, 10, "boxes = %0.f", "Courier#18", 1, num_boxes);
   digits(535, 40, "fragments = %0.f", "Courier#18", 1, num_fragments);
   flags = VISIBLE;
}

 
function new_fragment(VECTOR* pos )
{
   var c1;   for(c1=0; c1<35; c1++)
   {
      var idx;   for(idx=0; idx<1000; idx++)   if(Objects[idx]==NULL)   break;
      Objects[idx] = ent_create("bluspark.bmp",vector(pos.x,pos.y,pos.z),NULL);
      if(idx>Top_obj)   Top_obj=idx;   //raise Top_obj if this is highest
      Objects[idx].otype = 1;    //set to "fragment" type
      Objects[idx].lifetime = 200+random(500);
      //Objects[idx].pan = 180 - angle1;
      vec_scale(Objects[idx].scale_x,1.925);
      Objects[idx].roll = 1;
      vec_set(Objects[idx].velx,vector((random(25)-12.5)/2,(random(25)-12.5)/2,(-5+random(25))*5));
      Objects[idx].skill26 = 180 - random(100);
      set(Objects[idx],BRIGHT|OVERLAY|TRANSLUCENT|PASSABLE|MOVE);
      Objects[idx].alpha = 50;
      //do_sprite(Objects[idx],Objects[idx].velx,Objects[idx].vely,Objects[idx].velz);
      num_fragments += 1;
   }
}


function new_bomb()
{
   wait(1);
   var idx;   for(idx=0; idx<1000; idx++)   if(Objects[idx]==NULL)   break;
   Objects[idx] = ent_create("cube_smaller.mdl",vector(0,0,800),NULL);
   if(idx>Top_obj)   Top_obj=idx;   //raise Top_obj if this is highest
   Objects[idx].otype = 0;    //set to "bomb" type
   vec_scale(Objects[idx].scale_x,16.925);
   Objects[idx].lifetime = 500 + random(1000);
   wait(1);
   c_setminmax(Objects[idx]);
   phent_settype (Objects[idx], PH_RIGID, PH_SPHERE); // set the physics entity type
   phent_setmass (Objects[idx], 200, PH_SPHERE); // and its mass
   phent_setfriction (Objects[idx], 68); // set the friction
   phent_setdamping (Objects[idx], 5, 5); // set the damping
   phent_setelasticity (Objects[idx], 62, 12); // set the elasticity
   var dampener = 0.285;
   phent_addvelglobal(Objects[idx], vector((-50+random(100))*dampener,(-50+random(100))*dampener,(-5+random(10))*dampener), vector(100,0,0) );
   num_boxes += 1;
}


function main()
{
   var idx;   for(idx=0; idx<1000; idx++)   Objects[idx]=NULL;   // initialise object array
   video_mode=9;
   fps_max = 60;
   max_entities = 15000;
   max_nexus = 100000;
   vec_set(screen_color,vector(0,0,0));
   level_load("");
   wait(1);
   ph_setautodisable(0.00001, 0.0002, 4, 41); // turn on and set default values

   ENTITY* FLOOR = ent_create ("plain3d1.mdl", vector(-400, 0, -50), NULL); // create the floor
   FLOOR.scale_x=5000;
   FLOOR.scale_y=5000;
   FLOOR.scale_z=30;
   vec_set(FLOOR.blue,nullvector);
   FLOOR.ambient = 25;
   set(FLOOR,LIGHT);

   vec_set(camera.x,vector(5500,20,250));
   camera.arc = 110;
   camera.pan = 180;
   camera.ambient = -92; 

   ph_setgravity (vector(0, 0, -886)); // set the gravity
   
   var new_ball_delay = 0;
   while (1)
   {
      new_ball_delay -= 1;
      
      // CONTROLS
      mouse_pos.x = mouse_cursor.x;
      mouse_pos.y = mouse_cursor.y;
      camera.pan -= mouse_force.x * 26;
      camera.tilt += mouse_force.y * 26;
      mouse_pos.x = 160;
      mouse_pos.y = 120;
      if(key_cuu) camera.x -= 52 * time_step; 
      if(key_cud) camera.x += 52 * time_step; 
      if(key_cul) camera.y += 52 * time_step;
      if(key_cur) camera.y -= 52 * time_step;   
      if(key_ins) camera.z -= 52 * time_step;
      if(key_del) camera.z += 52 * time_step;
      if(mouse_left)      camera.ambient += 1;
      if(mouse_right)     camera.ambient -= 1;
      if((key_f)&&(new_ball_delay<0))
      {
         new_fragment(vector(0,0,800));
         new_ball_delay = 1;
      }
      if((key_b)&&(new_ball_delay<0))
      {
         new_bomb();
         new_ball_delay = 5;
      }
      //
      if (random(100)>97)   new_bomb();
      //
      var idx;   for(idx=0; idx<Top_obj; idx++)   //check all possible objects
      {   if(Objects[idx]!=NULL)      //if not empty,  then check it
         {   if(Objects[idx].otype==0)   //if its a bomb,  do this
            {   Objects[idx].lifetime -= 2;   //reduce bomb counter   
               if(Objects[idx].lifetime<=0)
               {   new_fragment(Objects[idx].x);   //trigger explosion
                  phent_settype(Objects[idx], NULL, NULL);    //remove object from physics
                  ent_remove(Objects[idx]);      //remove timed-out bomb
                  Objects[idx] = NULL;            //cleanup empty pointer
                  if(Top_obj==idx)   Top_obj--;   //lower Top_obj if it was this one.
                  num_boxes -= 1;
               }
            }
            else if(Objects[idx].otype==1)      //if its a fragment,  do this
            {   Objects[idx].lifetime -= 15;   //reduce counter
               if (random(100)>97)      Objects[idx].lifetime += 150;   //boost counter
               vec_add(Objects[idx].x, Objects[idx].velx);
               Objects[idx].z -= Objects[idx].skill27/8;
               Objects[idx].skill27 += 1;
               if (Objects[idx].lifetime>Objects[idx].skill26)
               {   Objects[idx].scale_x = (Objects[idx].lifetime * Objects[idx].lifetime)/14000;
                  Objects[idx].scale_y = (Objects[idx].lifetime * Objects[idx].lifetime)/14000;
               }
               if (Objects[idx].lifetime<10)      Objects[idx].alpha = Objects[idx].lifetime * 0.01;
               if(Objects[idx].lifetime<=0)
               {   ent_remove(Objects[idx]);      //remove timed-out fragment
                  Objects[idx] = NULL;            //cleanup empty pointer
                  if(Top_obj==idx)   Top_obj--;   //lower Top_obj if it was this one.
                  num_fragments -= 1;
               }
            }
         }
      }   
      //
      wait(1);
   }
}