Free Hero Mesh

  v=send_message(n2,n1,MSG_COLLIDING,NVALUE(objects[n2]->x),NVALUE(objects[n2]->y),NVALUE(r2));
  if(v.t) Throw("Type mismatch");
  h|=v.u;
  if((h&0x0002) && try_sharp(n1,n2)) h|=0x0004;
  if((h&0x00020000) && try_sharp(n2,n1)) h|=0x00040000;
  return h;
}

static inline Uint8 find_deferred_movement_loop(Uint32 obj,Uint8 xx,Uint8 yy) {
  // At this point, it is necessary to check for a loop, which may be like the diagram below:
  //     >>>>>>>v
  //        ^<<<<
  // The loop may also have a different shape.
  // If a loop is found, call the handle_colliding function to determine what to do next.
  // If there is no loop, allow the move to be retried later, trying objE's location next.
  // Since there may be multiple objects in a location, which move in different directions,
  // a variable "ch" mentions the next object to try, if it is VOIDLINK. If not, then once
  // it reaches the end without finding a loop, it can try the next one, resetting ch to
  // VOIDLINK. This will find not only loops, but also if there is a branch that is later
  // merged; due to what this program needs to do, and how they will be dealt with after
  // the potential loop is found, that isn't a problem.
  static sqlite3_uint64 board[64]; // bit board for locations with possible collisions
  Object*o=objects[obj];
  Uint32 ch=VOIDLINK; // first object found in same place as other where it must be checked
  Uint8 x=o->x;
  Uint8 y=o->y;
  Uint32 n,nn;
  memset(board,0,sizeof(board));
  begin:
  if(x==xx && y==yy) return 1;
  if(x<1 || x>pfwidth || y<1 || y>pfheight) goto notfound;
  if(board[y-1]&(1ULL<<(x-1))) return 0;
  board[y-1]|=1ULL<<(x-1);
  n=playfield[x+y*64-65];
  nn=VOIDLINK;
  while(n!=VOIDLINK) {
    o=objects[n];
    if((o->oflags&(OF_MOVING|OF_VISUALONLY|OF_DESTROYED))==OF_MOVING && o->height>0) {
      if(nn==VOIDLINK) {
        nn=n;
        if(ch!=VOIDLINK) goto found;
      } else if(ch==VOIDLINK) {
        ch=n;
        goto found;
      }
    }
    up:
    n=o->up;
  }
  if(nn==VOIDLINK) {
    notfound:
    if(ch==VOIDLINK) return 0;
    o=objects[n=ch];
    x=o->x;
    y=o->y;
    ch=VOIDLINK;
    goto up;
  }
  found:
  o=objects[nn];
  x+=x_delta[o->dir];
  y+=y_delta[o->dir];
  goto begin;
}

static Uint32 deferred_colliding(Uint32 obj,int x,int y) {
  Object*o=objects[obj];
  Object*oE;
  Uint32 h=0xFFFFFFFF;
  Uint32 objE=playfield[x+y*64-65];
  Uint8 d;
  int xx,yy;
  while(objE!=VOIDLINK) {
    oE=objects[objE];
    if(!(oE->oflags&(OF_DESTROYED|OF_VISUALONLY))) {
      if(oE->oflags&OF_MOVING) {
        // At this point, it is necessary to check for a loop, which may be like the diagram below:
      if((oE->oflags&OF_MOVING) && oE->height>0) {
        if(find_deferred_movement_loop(objE,objects[obj]->x,objects[obj]->y)) {
        //     >>>>>>>v
        //        ^<<<<
        // The loop may also have a different shape.
        // If a loop is found, call the handle_colliding function to determine what to do next.
          h&=handle_colliding(obj,objE,3,3);
        // If there is no loop, allow the move to be retried later, trying objE's location next.
        
      }
      if(oE->height>o->climb || (classes[o->class]->collisionLayers&classes[oE->class]->collisionLayers)) {
        } else {
          return h&4;
        }
      } else if(oE->height>o->climb || (classes[o->class]->collisionLayers&classes[oE->class]->collisionLayers)) {
        h&=handle_colliding(obj,objE,1,0);
        
      }
    }
    objE=oE->up;
  }
  
  // Find other objects trying to move to the same place
  if(h&8) for(d=0;d<8;d++) {
    xx=x-x_delta[d];
    yy=y-y_delta[d];
    if(xx<1 || xx>pfwidth || yy<1 || yy>pfheight) continue;
    objE=playfield[xx+yy*64-65];
    while(objE!=VOIDLINK) {
      oE=objects[objE];
      if(obj!=objE && (oE->oflags&OF_MOVING) && oE->dir==d && !(oE->oflags&OF_DESTROYED)) {
        if(o->height>oE->climb || oE->height>o->climb || (classes[o->class]->collisionLayers&classes[oE->class]->collisionLayers)) {
          h&=handle_colliding(obj,objE,2,2);
          
        }
      }
      objE=oE->up;
    }
    
  }
  }
  
  return ~h;
}

static void do_deferred_moves(void) {
  Object*o;
  Object*p;
  Uint32 h,n;

          re=1;
          o->oflags=(o->oflags|OF_MOVED)&~OF_MOVING;
          i-=65;
          if(i<0) i=0;
          goto retry;
        }
        stop:
        if(!(h&4)) o->oflags&=~OF_MOVING;
        if((h&5)!=4) o->oflags&=~OF_MOVING;
      }
      skip:
      n=o->up;
    }
  }
  if(re) goto restart;
}