| /* |
| * 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; |
| } |