Free Hero Mesh

  objects[n]=0;
  generation_number_inc=1;
}

static inline Uint8 resolve_dir(Uint32 n,Uint32 d) {
  return d<8?d:(objects[n]->dir+d)&7;
}

/*
  Working of animation: There are two separate animations, being logical
  and visual animations. New animations replace the current logical
  animation; if there isn't one, but there is a visual animation, then a
  new logical animation is added at the end. The logical animation is
  always at the same step or ahead of the visual animation.

  - lstep - Step number of the logical animation; this cannot equal or
  exceed max_animation. Only a single logical step is present at once.

  - vstep - Step number of the visual animation; this cannot equal or
  exceed max_animation. The tail of the visual animation is the same as
  the head of the logical animation, and the buffer is circular.

  - status - Contains bit flags. If the ANISTAT_LOGICAL flag is set, then
  it means a logical animation is active. If the ANISTAT_VISUAL flag is
  set, then it means a visual animation is active. ANISTAT_SYNCHRONIZED
  is set only for synchronized animations, which are visual only.

  - ltime - Amount of logical time passed

  - vtime - Number of centiseconds elapsed.

  - vimage - If the status field has the ANISTAT_VISUAL bit set, then this
  will decide the picture to display rather than using the object's image.

  - count - Number of logical animation steps so far this turn. If it is
  equal to max_animation then no more animations can be added this turn.

  Synchronized animations only use vstep, status, and vimage.
*/

static Animation*animalloc(void) {
  Animation*a=malloc(sizeof(Animation)+max_animation*sizeof(AnimationStep));
  if(!a) fatal("Allocation failed\n");
  a->lstep=a->vstep=a->ltime=a->vtime=a->status=a->count=0;
  return a;
}

static void animate(Uint32 n,Uint32 f,Uint32 a0,Uint32 a1,Uint32 t) {
  Animation*an=objects[n]->anim;
  objects[n]->image=a0;
  f&=0x0A;
  if(!an) an=objects[n]->anim=animalloc();
  if(an->status&ANISTAT_SYNCHRONIZED) an->status=0;
  if(an->count==max_animation) f=ANI_STOP;
  if(f&(ANI_ONCE|ANI_LOOP)) {
    switch(an->status) {
      case 0:
        an->vtime=an->lstep=an->vstep=0;
        an->vimage=a0;
        break;
      case ANISTAT_LOGICAL:
        an->vstep=an->lstep;
        an->vtime=0;
        an->vimage=a0;
        break;
      case ANISTAT_VISUAL:
        an->lstep++;
        if(an->lstep>=max_animation) an->lstep=0;
        if(an->lstep==an->vstep && max_animation>1) {
          an->vstep++;
          if(an->vstep==max_animation) an->vstep=0;
          an->vimage=an->step[an->vstep].start;
          an->vtime=0;
        }
        break;
      case ANISTAT_VISUAL|ANISTAT_LOGICAL:
        if(an->lstep==an->vstep) {
          an->vimage=a0;
          an->vtime=0;
        }
        break;
    }
    an->step[an->lstep].flag=f;
    an->step[an->lstep].start=a0;
    an->step[an->lstep].end=a1;
    an->step[an->lstep].speed=t;
    an->ltime=0;
    an->status=ANISTAT_VISUAL|ANISTAT_LOGICAL;
    an->count++;
  } else if(an->lstep==an->vstep) {
    an->status=0;
  } else if(an->status&ANISTAT_LOGICAL) {
    an->lstep=(an->lstep?:max_animation)-1;
    an->status&=~ANISTAT_LOGICAL;
  }
}

static void animate_sync(Uint32 n,Uint32 sl,Uint32 a0) {
  Animation*an=objects[n]->anim;
  objects[n]->image=a0;
  sl&=7;
  if(!an) an=objects[n]->anim=animalloc();
  an->status=ANISTAT_VISUAL|ANISTAT_SYNCHRONIZED;
  an->vimage=a0+anim_slot[sl].frame;
  an->lstep=an->vstep=0;
  an->step->flag=ANI_LOOP|ANI_SYNC;
  an->step->start=a0;
  an->step->slot=sl;
}

static Uint32 obj_above(Uint32 i) {
  Object*o;
  if(i==VOIDLINK) return VOIDLINK;
  o=objects[i];
  i=o->up;

    case OP_STRENGTH_E: NoIgnore(); StackReq(1,0); t1=Pop(); Numeric(t1); o->strength=t1.u; break;
    case OP_STRENGTH_E16: NoIgnore(); StackReq(1,0); t1=Pop(); Numeric(t1); o->strength=t1.u&0xFFFF; break;
    case OP_STRENGTH_EC: NoIgnore(); StackReq(2,0); t1=Pop(); Numeric(t1); i=v_object(Pop()); if(i!=VOIDLINK) o->strength=t1.u; break;
    case OP_STRENGTH_EC16: NoIgnore(); StackReq(2,0); t1=Pop(); Numeric(t1); i=v_object(Pop()); if(i!=VOIDLINK) o->strength=t1.u; break;
    case OP_SOUND: StackReq(2,0); t2=Pop(); t1=Pop(); break; // Sound not implemented at this time
    case OP_SUB: StackReq(2,1); t2=Pop(); Numeric(t2); t1=Pop(); Numeric(t1); Push(NVALUE(t1.u-t2.u)); break;
    case OP_SWAP: StackReq(2,2); t1=Pop(); t2=Pop(); Push(t1); Push(t2); break;
    case OP_SYNCHRONIZE: StackReq(2,0); t2=Pop(); Numeric(t2); t1=Pop(); Numeric(t1); animate_sync(obj,t1.u,t2.u); break;
    case OP_TRACE: StackReq(3,0); trace_stack(obj); break;
    case OP_TUCK: StackReq(2,3); t2=Pop(); t1=Pop(); Push(t2); Push(t1); Push(t2); break;
    case OP_USERSIGNAL: StackReq(0,1); if(o->oflags&OF_USERSIGNAL) Push(NVALUE(1)); else Push(NVALUE(0)); break;
    case OP_USERSIGNAL_C: StackReq(1,1); GetFlagOf(OF_USERSIGNAL); break;
    case OP_USERSIGNAL_E: NoIgnore(); StackReq(1,0); if(v_bool(Pop())) o->oflags|=OF_USERSIGNAL; else o->oflags&=~OF_USERSIGNAL; break;
    case OP_USERSIGNAL_EC: NoIgnore(); StackReq(2,0); SetFlagOf(OF_USERSIGNAL); break;
    case OP_USERSTATE: StackReq(0,1); if(o->oflags&OF_USERSTATE) Push(NVALUE(1)); else Push(NVALUE(0)); break;

  all_flushed=0;
  lastimage_processing=0;
  vstackptr=0;
  current_key=key;
  for(n=0;n<nobjects;n++) if(objects[n]) {
    objects[n]->distance=0;
    objects[n]->oflags&=~(OF_KEYCLEARED|OF_DONE);
    if(objects[n]->anim) objects[n]->anim->count=0;
  }
  
  current_key=0;
  if(key_ignored) return changed?"Invalid use of IgnoreKey":0;
  move_number++;
  
  if(generation_number<=TY_MAXTYPE) return "Too many generations of objects";