98e75f2d |
1 | /* |
2 | * Glide64 - Glide video plugin for Nintendo 64 emulators. |
3 | * Copyright (c) 2002 Dave2001 |
4 | * Copyright (c) 2003-2009 Sergey 'Gonetz' Lipski |
5 | * |
6 | * This program is free software; you can redistribute it and/or modify |
7 | * it under the terms of the GNU General Public License as published by |
8 | * the Free Software Foundation; either version 2 of the License, or |
9 | * any later version. |
10 | * |
11 | * This program is distributed in the hope that it will be useful, |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
14 | * GNU General Public License for more details. |
15 | * |
16 | * You should have received a copy of the GNU General Public License |
17 | * along with this program; if not, write to the Free Software |
18 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
19 | */ |
20 | |
21 | //**************************************************************** |
22 | // |
23 | // Glide64 - Glide Plugin for Nintendo 64 emulators |
24 | // Project started on December 29th, 2001 |
25 | // |
26 | // Authors: |
27 | // Dave2001, original author, founded the project in 2001, left it in 2002 |
28 | // Gugaman, joined the project in 2002, left it in 2002 |
29 | // Sergey 'Gonetz' Lipski, joined the project in 2002, main author since fall of 2002 |
30 | // Hiroshi 'KoolSmoky' Morii, joined the project in 2007 |
31 | // |
32 | //**************************************************************** |
33 | // |
34 | // To modify Glide64: |
35 | // * Write your name and (optional)email, commented by your work, so I know who did it, and so that you can find which parts you modified when it comes time to send it to me. |
36 | // * Do NOT send me the whole project or file that you modified. Take out your modified code sections, and tell me where to put them. If people sent the whole thing, I would have many different versions, but no idea how to combine them all. |
37 | // |
38 | //**************************************************************** |
39 | // |
40 | // CRC32 calculation functions |
41 | // |
42 | // Created by Gonetz, 2004 |
43 | // |
44 | //**************************************************************** |
45 | //* |
46 | |
47 | #define CRC32_POLYNOMIAL 0x04C11DB7 |
48 | |
49 | unsigned int CRCTable[ 256 ]; |
50 | |
51 | unsigned int Reflect( unsigned int ref, char ch ) |
52 | { |
53 | unsigned int value = 0; |
54 | |
55 | // Swap bit 0 for bit 7 |
56 | // bit 1 for bit 6, etc. |
57 | for (char i = 1; i < (ch + 1); i++) |
58 | { |
59 | if(ref & 1) |
60 | value |= 1 << (ch - i); |
61 | ref >>= 1; |
62 | } |
63 | return value; |
64 | } |
65 | |
66 | void CRC_BuildTable() |
67 | { |
68 | unsigned int crc; |
69 | |
70 | for (unsigned i = 0; i <= 255; i++) |
71 | { |
72 | crc = Reflect( i, 8 ) << 24; |
73 | for (unsigned j = 0; j < 8; j++) |
74 | crc = (crc << 1) ^ (crc & (1 << 31) ? CRC32_POLYNOMIAL : 0); |
75 | |
76 | CRCTable[i] = Reflect( crc, 32 ); |
77 | } |
78 | } |
79 | //*/ |
80 | //* |
81 | unsigned int CRC32( unsigned int crc, void *buffer, unsigned int count ) |
82 | { |
83 | unsigned int orig = crc; |
84 | unsigned char * p = reinterpret_cast<unsigned char*>(buffer); |
85 | while (count--) |
86 | crc = (crc >> 8) ^ CRCTable[(crc & 0xFF) ^ *p++]; |
87 | return crc ^ orig; |
88 | } |
89 | //*/ |
90 | |
91 | /* |
92 | wxUint32 CRC_Calculate( wxUint32 crc, void *buffer, wxUint32 count ) |
93 | { |
94 | wxUint32 Crc32=crc; |
95 | __asm { |
96 | mov esi, buffer |
97 | mov ecx, count |
98 | mov edx, crc |
99 | xor eax, eax |
100 | |
101 | loop1: |
102 | inc esi |
103 | mov al, dl |
104 | xor al, byte ptr [esi] |
105 | shr edx, 8 |
106 | mov ebx, [CRCTable+eax*4] |
107 | xor edx, ebx |
108 | |
109 | loop loop1 |
110 | |
111 | xor Crc32, edx |
112 | } |
113 | return Crc32; |
114 | } |
115 | */ |
116 | |
117 | /* |
118 | unsigned int CRC_Calculate( unsigned int crc, void *buffer, unsigned int count ) |
119 | { |
120 | unsigned int Crc32=crc; |
121 | __asm { |
122 | mov esi, buffer |
123 | mov edx, count |
124 | add edx, esi |
125 | mov ecx, crc |
126 | |
127 | loop1: |
128 | mov bl, byte ptr [esi] |
129 | movzx eax, cl |
130 | inc esi |
131 | xor al, bl |
132 | shr ecx, 8 |
133 | mov ebx, [CRCTable+eax*4] |
134 | xor ecx, ebx |
135 | |
136 | cmp edx, esi |
137 | jne loop1 |
138 | |
139 | xor Crc32, ecx |
140 | } |
141 | return Crc32; |
142 | } |
143 | //*/ |
144 | |