Free Hero Mesh

#define Push(x) (vstack[vstackptr++]=(x))
#define Pop() (vstack[--vstackptr])

// For arrival/departure masks
#define Xbit(a) ((a)%5-2)
#define Ybit(a) (2-(a)/5)

static void execute_program(Uint16*code,int ptr,Uint32 obj);
static Value send_message(Uint32 from,Uint32 to,Uint16 msg,Value arg1,Value arg2,Value arg3);
static Uint32 broadcast(Uint32 from,int c,Uint16 msg,Value arg1,Value arg2,Value arg3,Uint8 s);
static Value destroy(Uint32 from,Uint32 to,Uint32 why);

static const Sint8 x_delta[8]={1,1,0,-1,-1,-1,0,1};
static const Sint8 y_delta[8]={0,-1,-1,-1,0,1,1,1};

      if(n==VOIDLINK) Throw("No object specified in pattern");
      changed=1;
      objects[n]->dir=d;
      break;
    case OP_ELSE:
      ptr--;
      while(code[ptr]==OP_ELSE) ptr=code[ptr+2];
      break;
    case OP_FUNCTION:
      StackReq(0,2);
      Push(OVALUE(n));
      Push(NVALUE(d));
      execute_program(classes[0]->codes,functions[code[ptr++]],obj);
      StackReq(1,0);
      v=Pop();
      if(v.t==TY_NUMBER) {
        d=v.u&7;
      } else if(v.t==TY_MARK) {
        goto fail;
      } else if(v.t>TY_MAXTYPE) {
        n=v_object(v);
        x=objects[n]->x;
        y=objects[n]->y;
      } else {
        Throw("Type mismatch");
      }
      break;
    case OP_HEIGHT:
      if(playfield[x+y*64-65]==VOIDLINK || height_at(x,y)<=objects[obj]->climb) goto fail;
      break;
    case OP_HEIGHT_C:
      g=code[ptr++];
      if(playfield[x+y*64-65]==VOIDLINK || height_at(x,y)<=g) goto fail;