/*

 * Copyright (C) 2002 RealVNC Ltd.  All Rights Reserved.

 * Copyright (C) 2003 Sun Microsystems, Inc.

 *

 * This 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 software 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 software; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,

 * USA.

 */

#include "zrlepalettehelper.h"

#include <assert.h>

#include <string.h>

#define ZRLE_HASH(pix) (((pix) ^ ((pix) >> 17)) & 4095)

void zrlePaletteHelperInit(zrlePaletteHelper *helper)

{

  memset(helper->palette, 0, sizeof(helper->palette));

  memset(helper->index, 255, sizeof(helper->index));

  memset(helper->key, 0, sizeof(helper->key));

  helper->size = 0;

}

void zrlePaletteHelperInsert(zrlePaletteHelper *helper, zrle_U32 pix)

{

  if (helper->size < ZRLE_PALETTE_MAX_SIZE) {

    int i = ZRLE_HASH(pix);

    while (helper->index[i] != 255 && helper->key[i] != pix)

      i++;

    if (helper->index[i] != 255) return;

    helper->index[i] = helper->size;

    helper->key[i] = pix;

    helper->palette[helper->size] = pix;

  }

  helper->size++;

}

int zrlePaletteHelperLookup(zrlePaletteHelper *helper, zrle_U32 pix)

{

  int i = ZRLE_HASH(pix);

  assert(helper->size <= ZRLE_PALETTE_MAX_SIZE);

  while (helper->index[i] != 255 && helper->key[i] != pix)

    i++;

  if (helper->index[i] != 255) return helper->index[i];

  return -1;

}