/*
   ** <<ACE>>
   **
   ** Amiga BASIC Compiler **
   **
   ** Parser: screens **
   ** Copyright (C) 1998 David Benn
   ** 
   ** This program is free software; you can redistribute it and/or
   ** modify it under the terms of the GNU General Public License
   ** as published by the Free Software Foundation; either version 2
   ** of the License, or (at your option) any later version.
   **
   ** This program is distributed in the hope that it will be useful,
   ** but WITHOUT ANY WARRANTY; without even the implied warranty of
   ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   ** GNU General Public License for more details.
   **
   ** You should have received a copy of the GNU General Public License
   ** along with this program; if not, write to the Free Software
   ** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
   **
   ** Author: David J Benn
   **   Date: 16th February 1994 (code removed from statement.c)
 */

#include "acedef.h"

/* external */
extern int sym;

/* functions */
void screen (void)
{
/*
   ** SCREEN [CLOSE|FORWARD|BACK]
 */
  int rword, stype;

  insymbol ();

  /* SCREEN CLOSE screen-id */
  if (sym == closesym)
    {
      insymbol ();
      make_sure_short (expr ());	/* screen-id */
      gen ("move.w", "(sp)+", "d0");
      gen ("jsr", "_closescreen", "  ");
      enter_XREF ("_closescreen");
      enter_XREF ("_IntuitionBase");
    }
  else
    /* SCREEN FORWARD|BACK screen-id */
  if (sym == forwardsym || sym == backsym)
    {
      rword = sym;

      insymbol ();
      stype = expr ();
      if (stype == stringtype)
	_error (4);
      else
	{
	  /* screen-id */
	  make_sure_short (stype);
	  gen ("move.w", "(sp)+", "d0");

	  /* forward or back? */
	  switch (rword)
	    {
	    case forwardsym:
	      gen ("move.w", "#1", "d1");
	      break;
	    case backsym:
	      gen ("move.w", "#2", "d1");
	      break;
	    }

	  gen ("jsr", "_change_screen_depth", "  ");

	  enter_XREF ("_change_screen_depth");
	  enter_XREF ("_IntuitionBase");
	}
    }
  else
    /* SCREEN screen-id,width,height,colors,mode */
    {
      /* open a screen */
      make_sure_short (expr ());	/* screen-id */
      if (sym != comma)
	_error (16);
      else
	{
	  insymbol ();
	  make_sure_short (expr ());	/* width */
	  if (sym != comma)
	    _error (16);
	  else
	    {
	      insymbol ();
	      make_sure_short (expr ());	/* height */
	      if (sym != comma)
		_error (16);
	      else
		{
		  insymbol ();
		  make_sure_short (expr ());	/* depth */
		  if (sym != comma)
		    _error (16);
		  else
		    {
		      insymbol ();
		      make_sure_short (expr ());	/* mode */

		      /* pop parameters */
		      gen ("move.w", "(sp)+", "d4");	/* mode */
		      gen ("move.w", "(sp)+", "d3");	/* depth */
		      gen ("move.w", "(sp)+", "d2");	/* height */
		      gen ("move.w", "(sp)+", "d1");	/* width */
		      gen ("move.w", "(sp)+", "d0");	/* screen-id (1-9) */

		      /* open the screen */
		      gen ("jsr", "_openscreen", "  ");
		      enter_XREF ("_openscreen");
		      enter_XREF ("_GfxBase");
		    }
		}
	    }
	}
    }
}