/*
 * crt.c:
 *
 * Copyright (c) 2008 James McKenzie <james@fishsoup.dhs.org>,
 * All rights reserved.
 *
 */

static char rcsid[] = "$Id$";

/*
 * $Log$
 * Revision 1.8  2008/02/07 13:19:48  james
 * *** empty log message ***
 *
 * Revision 1.7  2008/02/07 12:41:06  james
 * *** empty log message ***
 *
 * Revision 1.6  2008/02/07 12:16:04  james
 * *** empty log message ***
 *
 * Revision 1.5  2008/02/06 11:30:37  james
 * *** empty log message ***
 *
 * Revision 1.4  2008/02/05 01:11:46  james
 * *** empty log message ***
 *
 * Revision 1.3  2008/02/04 20:23:55  james
 * *** empty log message ***
 *
 * Revision 1.2  2008/02/04 02:05:06  james
 * *** empty log message ***
 *
 * Revision 1.1  2008/02/03 23:31:25  james
 * *** empty log message ***
 *
 */

#include "project.h"

void
crt_erase (CRT * c, CRT_Pos s, CRT_Pos e, int ea)
{
  CRT_CA *ps = &c->screen[CRT_ADDR_POS (&s)];
  CRT_CA *pe = &c->screen[CRT_ADDR_POS (&e)];

  while (ps <= pe)
    {
      ps->chr = ' ';
      if (ea){
        ps->attr = CRT_ATTR_NORMAL;
        ps->color = CRT_COLOR_NORMAL;
	}
      ps++;
    }

}

void
crt_cls (CRT * c)
{
  CRT_Pos s = { 0, 0 };
  CRT_Pos e = { CRT_COLS - 1, CRT_ROWS - 1 };
  int i;

  crt_erase (c, s, e, 1);
  c->sh.dir=0;
}

void
crt_scroll_up (CRT * c, CRT_Pos s, CRT_Pos e, int ea)
{
  int l, n;
  int p;


  s.x = 0;
  e.x = CRT_COLS - 1;

  c->sh.s=s;
  c->sh.e=e;
  c->sh.dir=-1;

  l = e.x - s.x;
  l++;
  l *= sizeof (CRT_CA);

  n = e.y - s.y;


  p = CRT_ADDR_POS (&s);

  while (n--)
    {
      memcpy (&c->screen[p], &c->screen[p + CRT_COLS], l);
      p += CRT_COLS;
    }

  s.y = e.y;
  crt_erase (c, s, e, ea);

}

void
crt_scroll_down (CRT * c, CRT_Pos s, CRT_Pos e, int ea)
{
  int l, n;
  int p;

  s.x = 0;
  e.x = CRT_COLS - 1;

  c->sh.s=s;
  c->sh.e=e;
  c->sh.dir=1;

  l = e.x - s.x;
  l++;
  l *= sizeof (CRT_CA);

  n = e.y - s.y;
  n++;

  p = CRT_ADDR_POS (&e);

  while (n--)
    {
      memcpy (&c->screen[p], &c->screen[p - CRT_COLS], l);
      p -= CRT_COLS;
    }

  e.y = s.y;
  crt_erase (c, s, e, ea);

}

void
crt_reset (CRT * c)
{
  crt_cls (c);

  c->pos.x = 0;
  c->pos.y = 0;
  c->hide_cursor = 1;
  c->sh.dir=0;
}

void
crt_insert (CRT * c, CRT_CA ca)
{
  if (c->pos.x < 0)
    c->pos.x = 0;
  if (c->pos.x >= CRT_COLS)
    c->pos.x = CRT_COLS - 1;
  if (c->pos.y < 0)
    c->pos.y = 0;
  if (c->pos.y >= CRT_ROWS)
    c->pos.y = CRT_ROWS - 1;

  c->screen[CRT_ADDR (c->pos.y, c->pos.x)] = ca;

  c->sh.dir=0;
}