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Minor cleanup.

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This commit is contained in:
n-a-c-h
2004-12-03 11:39:30 +00:00
parent 74f6fd2474
commit 7691f38ddd
1 changed files with 18 additions and 89 deletions
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105
zsnes/src/chips/sdd1emu.c
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@@ -1,3 +1,20 @@
//Copyright (C) 1997-2004 ZSNES Team ( zsknight@zsnes.com / _demo_@zsnes.com )
//
//This program 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 program 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 program; if not, write to the Free Software
//Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
/******************************************************************************* /*******************************************************************************
S-DD1 C emulator code S-DD1 C emulator code
(c) Copyright 2003 Brad Jorsch with research by (c) Copyright 2003 Brad Jorsch with research by
@@ -144,93 +161,6 @@ static inline unsigned char GetBit(unsigned char cur_bitplane){
return bit; return bit;
} }
void SDD1_decompress(unsigned char *out, unsigned char *in, int len){
unsigned char bit, i, plane;
unsigned char byte1, byte2;
if(len==0) len=0x10000;
bitplane_type=in[0]>>6;
switch(in[0]&0x30){
case 0x00:
high_context_bits=0x01c0;
low_context_bits =0x0001;
break;
case 0x10:
high_context_bits=0x0180;
low_context_bits =0x0001;
break;
case 0x20:
high_context_bits=0x00c0;
low_context_bits =0x0001;
break;
case 0x30:
high_context_bits=0x0180;
low_context_bits =0x0003;
break;
}
in_stream=(in[0]<<11) | (in[1]<<3);
valid_bits=5;
in_buf=in+2;
memset(bit_ctr, 0, sizeof(bit_ctr));
memset(context_states, 0, sizeof(context_states));
memset(context_MPS, 0, sizeof(context_MPS));
memset(prev_bits, 0, sizeof(prev_bits));
switch(bitplane_type){
case 0:
while(1) {
for(byte1=byte2=0, bit=0x80; bit; bit>>=1){
if(GetBit(0)) byte1 |= bit;
if(GetBit(1)) byte2 |= bit;
}
*(out++)=byte1;
if(!--len) return;
*(out++)=byte2;
if(!--len) return;
}
break;
case 1:
i=plane=0;
while(1) {
for(byte1=byte2=0, bit=0x80; bit; bit>>=1){
if(GetBit(plane)) byte1 |= bit;
if(GetBit(plane+1)) byte2 |= bit;
}
*(out++)=byte1;
if(!--len) return;
*(out++)=byte2;
if(!--len) return;
if(!(i+=32)) plane = (plane+2)&7;
}
break;
case 2:
i=plane=0;
while(1) {
for(byte1=byte2=0, bit=0x80; bit; bit>>=1){
if(GetBit(plane)) byte1 |= bit;
if(GetBit(plane+1)) byte2 |= bit;
}
*(out++)=byte1;
if(!--len) return;
*(out++)=byte2;
if(!--len) return;
if(!(i+=32)) plane ^= 2;
}
break;
case 3:
do {
for(byte1=plane=0, bit=1; bit; bit<<=1, plane++){
if(GetBit(plane)) byte1 |= bit;
}
*(out++)=byte1;
} while(--len);
break;
}
}
static unsigned char cur_plane; static unsigned char cur_plane;
static unsigned char num_bits; static unsigned char num_bits;
static unsigned char next_byte; static unsigned char next_byte;
@@ -326,4 +256,3 @@ unsigned char SDD1_get_byte(void){
return 0; return 0;
} }
} }