/*
 * pointer.c
 *
 * Handling of pointer-shape changing
 *
 * © 1994-1998 Straylight
 */

/*----- Licensing note ----------------------------------------------------*
 *
 * This file is part of Straylight's Steel library.
 *
 * Steel 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, or (at your option)
 * any later version.
 *
 * Steel 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 Steel.  If not, write to the Free Software Foundation,
 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#include <stdio.h>

#include "os.h"
#include "sprite.h"
#include "swis.h"
#include "wimpt.h"
#include "pointer.h"

static BOOL pointer__notDefault;

/*
 * os_error *pointer__magicSpriteOp(sprite_area *a,
 *                                  sprite _id *sid,
 *                                  os_regset *r)
 *
 * Use
 *  Performs a sprite op of the appropriate kind for the sprite area given.
 *
 * Parameters
 *  sprite_area *a == the sprite area to do the op on
 *  sprite_id *sid == the sprite id to do it to
 *  os_regset r == other registers for the op
 *
 * Returns
 *  An error or 0.
 */

static os_error *pointer__magicSpriteOp(sprite_area *a,
                                        sprite_id *sid,
                                        os_regset *r)
{
  if (a==(sprite_area *)1)
  {
    /* --- The WIMP sprite area --- */

    r->r[0]&=~0x300;
    r->r[2]=(int)sid->s.name;
    return (os_swix(XWimp_SpriteOp,r));
  }
  else if (!a)
  {
    /* --- The nasty system sprite area --- */

    r->r[0]&=~0x300;
    r->r[2]=(int)sid->s.name;
    return (os_swix(XOS_SpriteOp,r));
  }
  else
  {
    /* --- A nice user sprite area --- */

    r->r[0]&=~0x300;
    if (sid->tag)
    {
      r->r[0]|=0x200;
      r->r[2]=(int)sid->s.addr;
    }
    else
    {
      r->r[0]|=0x100;
      r->r[2]=(int)sid->s.name;
    }
    r->r[1]=(int)a;

    return (os_swix(XOS_SpriteOp,r));
  }
}

/*
 * BOOL pointer__spriteExist(sprite_area *a,char *name)
 *
 * Use
 *  Returns whether a named sprite exists in the given area
 *
 * Parameters
 *  sprite_area *a == the sprite area
 *  char *name == the name of the sprite to test
 *
 * Returns
 *  TRUE if the sprite is there
 */

static BOOL pointer__spriteExist(sprite_area *a,char *name)
{
  os_regset r;
  sprite_id sid;

  sid.s.name=name;
  sid.tag=0;

  r.r[0]=40;
  return (!pointer__magicSpriteOp(a,&sid,&r));
}

/*
 * os_error *pointer_set_shape(sprite_area *a,sprite_id *sid,int x,int y)
 *
 * Use
 *  Sets the pointer shape to be the pointer specified.  If a pointer with
 *  name `name<dx><dy>' is found in the sprite area, that's used instead, and
 *  the active point is scaled assuming that the original was specified in
 *  mode-8 type coordinates.
 *
 * Parameters
 *  sprite_area *a == the sprite area containing the sprite
 *  sprite_id *sid == pointer to the sprite identifier (dumb idea)
 *  int x,int y == coordinates (in pixels) of the hot-spot
 */

os_error *pointer_set_shape(sprite_area *a,sprite_id *sid,int x,int y)
{
  char buffer[15];
  sprite_id s;
  os_regset r;

  if (!sid->tag)
  {
    /* --- Try and find a good match for the mode --- */

    sprintf(buffer,"%s%i%i",sid->s.name,wimpt_dx(),wimpt_dy());
    if (pointer__spriteExist(a,buffer))
    {
      s.s.name=buffer;
      s.tag=0;
      sid=&s;
      x=(x*2)/wimpt_dx();
      y=(y*4)/wimpt_dy();
    }
  }

  /* --- Now set up the pointer shape --- */

  r.r[0]=36;
  r.r[3]=2;                     /* Set everything up as nicely as possible */
  r.r[4]=x;
  r.r[5]=y;
  r.r[6]=r.r[7]=0;              /* No translation table, no zoom box       */
  pointer__notDefault=TRUE;
  return (pointer__magicSpriteOp(a,sid,&r));
}

/*
 * void pointer_reset_shape(void)
 *
 * Use
 *  Resets the pointer shape
 */

void pointer_reset_shape(void)
{
  if (pointer__notDefault)
    os_cli("%pointer");
  pointer__notDefault=FALSE;
}