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authorFranklin Wei <git@fwei.tk>2018-02-11 15:34:30 -0500
committerFranklin Wei <git@fwei.tk>2019-07-19 22:37:40 -0400
commit5d05b9d3e920a6aa5fcb553758e98ed0da8c91e4 (patch)
tree84406e21639529a185556a33e5de7f43cffc277b /apps/plugins/sdl/progs/quake/crc.c
parentb70fecf21ddc21877ec1ae7888d9c18a979e37ad (diff)
downloadrockbox-5d05b9d3e920a6aa5fcb553758e98ed0da8c91e4.tar.gz
rockbox-5d05b9d3e920a6aa5fcb553758e98ed0da8c91e4.zip
Quake!
This ports id Software's Quake to run on the SDL plugin runtime. The source code originated from id under the GPLv2 license. I used https://github.com/ahefner/sdlquake as the base of my port. Performance is, unsurprisingly, not on par with what you're probably used to on PC. I average about 10FPS on ipod6g, but it's still playable. Sound works well enough, but in-game music is not supported. I've written ARM assembly routines for the inner sound loop. Make sure you turn the "brightness" all the way down, or colors will look funky. To run, extract Quake's data files to /.rockbox/quake. Have fun! Change-Id: I4285036e967d7f0722802d43cf2096c808ca5799
Diffstat (limited to 'apps/plugins/sdl/progs/quake/crc.c')
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diff --git a/apps/plugins/sdl/progs/quake/crc.c b/apps/plugins/sdl/progs/quake/crc.c
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1/*
2Copyright (C) 1996-1997 Id Software, Inc.
3
4This program is free software; you can redistribute it and/or
5modify it under the terms of the GNU General Public License
6as published by the Free Software Foundation; either version 2
7of the License, or (at your option) any later version.
8
9This program is distributed in the hope that it will be useful,
10but WITHOUT ANY WARRANTY; without even the implied warranty of
11MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
12
13See the GNU General Public License for more details.
14
15You should have received a copy of the GNU General Public License
16along with this program; if not, write to the Free Software
17Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18
19*/
20/* crc.c */
21
22#include "quakedef.h"
23#include "crc.h"
24
25// this is a 16 bit, non-reflected CRC using the polynomial 0x1021
26// and the initial and final xor values shown below... in other words, the
27// CCITT standard CRC used by XMODEM
28
29#define CRC_INIT_VALUE 0xffff
30#define CRC_XOR_VALUE 0x0000
31
32static unsigned short crctable[256] =
33{
34 0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7,
35 0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad, 0xe1ce, 0xf1ef,
36 0x1231, 0x0210, 0x3273, 0x2252, 0x52b5, 0x4294, 0x72f7, 0x62d6,
37 0x9339, 0x8318, 0xb37b, 0xa35a, 0xd3bd, 0xc39c, 0xf3ff, 0xe3de,
38 0x2462, 0x3443, 0x0420, 0x1401, 0x64e6, 0x74c7, 0x44a4, 0x5485,
39 0xa56a, 0xb54b, 0x8528, 0x9509, 0xe5ee, 0xf5cf, 0xc5ac, 0xd58d,
40 0x3653, 0x2672, 0x1611, 0x0630, 0x76d7, 0x66f6, 0x5695, 0x46b4,
41 0xb75b, 0xa77a, 0x9719, 0x8738, 0xf7df, 0xe7fe, 0xd79d, 0xc7bc,
42 0x48c4, 0x58e5, 0x6886, 0x78a7, 0x0840, 0x1861, 0x2802, 0x3823,
43 0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969, 0xa90a, 0xb92b,
44 0x5af5, 0x4ad4, 0x7ab7, 0x6a96, 0x1a71, 0x0a50, 0x3a33, 0x2a12,
45 0xdbfd, 0xcbdc, 0xfbbf, 0xeb9e, 0x9b79, 0x8b58, 0xbb3b, 0xab1a,
46 0x6ca6, 0x7c87, 0x4ce4, 0x5cc5, 0x2c22, 0x3c03, 0x0c60, 0x1c41,
47 0xedae, 0xfd8f, 0xcdec, 0xddcd, 0xad2a, 0xbd0b, 0x8d68, 0x9d49,
48 0x7e97, 0x6eb6, 0x5ed5, 0x4ef4, 0x3e13, 0x2e32, 0x1e51, 0x0e70,
49 0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a, 0x9f59, 0x8f78,
50 0x9188, 0x81a9, 0xb1ca, 0xa1eb, 0xd10c, 0xc12d, 0xf14e, 0xe16f,
51 0x1080, 0x00a1, 0x30c2, 0x20e3, 0x5004, 0x4025, 0x7046, 0x6067,
52 0x83b9, 0x9398, 0xa3fb, 0xb3da, 0xc33d, 0xd31c, 0xe37f, 0xf35e,
53 0x02b1, 0x1290, 0x22f3, 0x32d2, 0x4235, 0x5214, 0x6277, 0x7256,
54 0xb5ea, 0xa5cb, 0x95a8, 0x8589, 0xf56e, 0xe54f, 0xd52c, 0xc50d,
55 0x34e2, 0x24c3, 0x14a0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405,
56 0xa7db, 0xb7fa, 0x8799, 0x97b8, 0xe75f, 0xf77e, 0xc71d, 0xd73c,
57 0x26d3, 0x36f2, 0x0691, 0x16b0, 0x6657, 0x7676, 0x4615, 0x5634,
58 0xd94c, 0xc96d, 0xf90e, 0xe92f, 0x99c8, 0x89e9, 0xb98a, 0xa9ab,
59 0x5844, 0x4865, 0x7806, 0x6827, 0x18c0, 0x08e1, 0x3882, 0x28a3,
60 0xcb7d, 0xdb5c, 0xeb3f, 0xfb1e, 0x8bf9, 0x9bd8, 0xabbb, 0xbb9a,
61 0x4a75, 0x5a54, 0x6a37, 0x7a16, 0x0af1, 0x1ad0, 0x2ab3, 0x3a92,
62 0xfd2e, 0xed0f, 0xdd6c, 0xcd4d, 0xbdaa, 0xad8b, 0x9de8, 0x8dc9,
63 0x7c26, 0x6c07, 0x5c64, 0x4c45, 0x3ca2, 0x2c83, 0x1ce0, 0x0cc1,
64 0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba, 0x8fd9, 0x9ff8,
65 0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2, 0x0ed1, 0x1ef0
66};
67
68void CRC_Init(unsigned short *crcvalue)
69{
70 *crcvalue = CRC_INIT_VALUE;
71}
72
73void CRC_ProcessByte(unsigned short *crcvalue, byte data)
74{
75 *crcvalue = (*crcvalue << 8) ^ crctable[(*crcvalue >> 8) ^ data];
76}
77
78unsigned short CRC_Value(unsigned short crcvalue)
79{
80 return crcvalue ^ CRC_XOR_VALUE;
81} \ No newline at end of file