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/*
* 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;
}
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