//This is an alternative window manager.
//It augments the existing one found
//in $LK,"::/LT/ADAM/WINDOW.CPZ","FI:::/LT/ADAM/WINDOW.CPZ"$.  It uses
//the real-time differential equation
//solver to reposition windows as though
//they were repulsively charged particles.

//I find this window manager to be a
//novelty, not desirable for actual
//use.  You're welcome to add it, or
//some variation to your start-up
//scripts if you like it.  It's not
//fully debugged.

//I had to cheat to make this work.
//I added $LK,"CRTf_HAS_BEEN_RESIZED2","MN:CRTf_HAS_BEEN_RESIZED2"$ and
//modified $LK,"::/LT/ADAM/WINDOW.CPZ","FI:::/LT/ADAM/WINDOW.CPZ"$.

Ode *o=NULL;
I8 tss_cnt=0;
TssStruct *tss_map=NULL;

void EndTsk()
{
  RemQue(o);
  OdeDel(o);
  Free(tss_map);
  Exit;
}

void MyDerivative(Ode *o,double t,Order2D3 *state,Order2D3 *DstateDt)
{
  U8 i,j;
  double f,d,dd,dx,dy;

  MemSet(DstateDt,0,sizeof(Order2D3)*tss_cnt);
  for (i=0;i<tss_cnt;i++) {
    DstateDt[i].x=state[i].DxDt;
    DstateDt[i].y=state[i].DyDt;
    for (j=0;j<tss_cnt;j++) {
      if (i!=j) {
	dx=state[i].x-state[j].x;
	dy=state[i].y-state[j].y;
	dd=Sqr(dx)+Sqr(dy)+1.0;
	d=Sqrt(dd);

	dx/=d;
	dy/=d;

	f=1000000.0/dd;

	DstateDt[i].DxDt+=f*dx;
	DstateDt[i].DyDt+=f*dy;
      }
    }
    DstateDt[i].DxDt-=1.0*state[i].DxDt;  //damping
    DstateDt[i].DyDt-=1.0*state[i].DyDt;
  }
}

void WinMngTsk()
{
  BoolU4 same;
  I8 i,x,y,j,cnt;
  Order2D3 *tempo;
  TssStruct *tss;

//This makes so this task doesn't get
//swapped-out unless voluntarily.
  Preempt(OFF);

  Fs->end_task_cb=&EndTsk;
  while (TRUE) {
    cnt=0;
    tss=Fs->next_tss;
    while (tss!=Fs) {
      if (Bt(&tss->crt_flags,CRTf_SHOW))
	cnt++;
      tss=tss->next_tss;
    }

    if (cnt==tss_cnt) {
      same=TRUE;
      i=0;
      tss=Fs->next_tss;
      while (tss!=Fs) {
	if (Bt(&tss->crt_flags,CRTf_SHOW))
	  if (tss_map[i++]!=tss)
	    same=FALSE;
	tss=tss->next_tss;
      }
    } else
      same=FALSE;
    if (!same) {
      tss_cnt=cnt;
      if (o) {
	RemQue(o);
	OdeDel(o);
	Free(tss_map);
      }
      o=OdeNew(cnt*sizeof(Order2D3));
      tss_map=MAlloc(sizeof(U4)*cnt);
      i=0;
      tss=Fs->next_tss;
      while (tss!=Fs) {
	if (Bt(&tss->crt_flags,CRTf_SHOW)) {
	  tss_map[i]=tss;
	  tempo=o->state+sizeof(Order2D3)*i;
	  tempo->x=(tss->window_left+tss->window_right)>>1;
	  tempo->y=(tss->window_top+tss->window_bottom)>>1;
	  tempo->z=0;
	  tempo->DxDt=0;
	  tempo->DyDt=0;
	  tempo->DzDt=0;
	  i++;
	}
	tss=tss->next_tss;
      }
      o->derivative=&MyDerivative;
      o->tolerance_start=.1;
      InsQue(o,Fs->last_ode);
    }
    Sleep(60);
    cnt=0;
    tss=Fs->next_tss;
    while (tss!=Fs) {
      if (Bt(&tss->crt_flags,CRTf_SHOW))
	cnt++;
      tss=tss->next_tss;
    }
    if (cnt==tss_cnt) {
      same=TRUE;
      i=0;
      tss=Fs->next_tss;
      while (tss!=Fs) {
	if (Bt(&tss->crt_flags,CRTf_SHOW))
	  if (tss_map[i++]!=tss)
	    same=FALSE;
	tss=tss->next_tss;
      }
    } else
      same=FALSE;
    if (same) {
      Bts(&sys_flags,SYSf_CLEAR_SCREEN_TEXT);
      for (i=0;i<tss_cnt;i++) {
	tss=tss_map[i];
	tempo=o->state+sizeof(Order2D3)*i;
	x=tss->window_right-tss->window_left;
	y=tss->window_bottom-tss->window_top;
	if (Bt(&tss->crt_flags,CRTf_HAS_BEEN_RESIZED2)) {
	  tempo->x=(tss->window_left+tss->window_right)>>1;
	  tempo->y=(tss->window_top+tss->window_bottom)>>1;
	  tempo->DxDt=0;
	  tempo->DyDt=0;
	} else {
	  j=tempo->x-x>>1;
	  j&=-4;
	  if (j<4) j=4;
	  if (j+x>tss->crt_width-12) j=tss->crt_width-x-12;
	  SetWindowHor(tss,j,j+x);
	  j=tempo->y-y>>1;
	  if (j<2) j=2;
	  if (j+y>tss->crt_height-3) j=tss->crt_height-y-3;
	  SetWindowVert(tss,j,j+y);

	  x=(tss->window_left+tss->window_right)>>1;
	  y=(tss->window_top+tss->window_bottom)>>1;
	  if (tempo->x>x+8) tempo->x=x+8;
	  if (tempo->y>y+2) tempo->y=y+2;
	  if (tempo->x<x-8) tempo->x=x-8;
	  if (tempo->y<y-2) tempo->y=y-2;
	  if (tempo->DxDt>32.0)  tempo->DxDt=32.0;
	  if (tempo->DyDt>8.0)	 tempo->DyDt=8.0;
	  if (tempo->DxDt<-32.0) tempo->DxDt=-32.0;
	  if (tempo->DyDt<-8.0)  tempo->DyDt=-8.0;
	}
	Btr(&tss->crt_flags,CRTf_HAS_BEEN_RESIZED2);
      }
    }
  }
}

Spawn(&WinMngTsk,"WINMGR2");