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fteqw/engine/common/huff.c

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/*
===========================================================================
Copyright (C) 1999-2005 Id Software, Inc.
This file is part of Quake III Arena source code.
Quake III Arena source code 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.
Quake III Arena source code 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 Quake III Arena source code; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
===========================================================================
*/
/* This is based on the Adaptive Huffman algorithm described in Sayood's Data
* Compression book. The ranks are not actually stored, but implicitly defined
* by the location of a node within a doubly-linked list */
#include "quakedef.h"
#ifdef HUFFNETWORK
#define NYT HMAX /* NYT = Not Yet Transmitted */
#define INTERNAL_NODE (HMAX+1)
typedef struct nodetype {
struct nodetype *left, *right, *parent; /* tree structure */
struct nodetype *next, *prev; /* doubly-linked list */
struct nodetype **head; /* highest ranked node in block */
int weight;
int symbol;
} node_t;
#define HMAX 256 /* Maximum symbol */
typedef struct {
int blocNode;
int blocPtrs;
node_t* tree;
node_t* lhead;
node_t* ltail;
node_t* loc[HMAX+1];
node_t** freelist;
node_t nodeList[768];
node_t* nodePtrs[768];
} huff_t;
struct huffman_s{
int counts[256];
unsigned int crc;
qboolean built;
huff_t compressor;
huff_t decompressor;
};
extern cvar_t net_compress;
static int bloc = 0;
/*
static void Huff_putBit( int bit, qbyte *fout, int *offset) {
bloc = *offset;
if ((bloc&7) == 0) {
fout[(bloc>>3)] = 0;
}
fout[(bloc>>3)] |= bit << (bloc&7);
bloc++;
*offset = bloc;
}
static int Huff_getBloc(void)
{
return bloc;
}
static void Huff_setBloc(int _bloc)
{
bloc = _bloc;
}
static int Huff_getBit( qbyte *fin, int *offset) {
int t;
bloc = *offset;
t = (fin[(bloc>>3)] >> (bloc&7)) & 0x1;
bloc++;
*offset = bloc;
return t;
}*/
/* Add a bit to the output file (buffered) */
static void huff_add_bit (char bit, qbyte *fout) {
if ((bloc&7) == 0) {
fout[(bloc>>3)] = 0;
}
fout[(bloc>>3)] |= bit << (bloc&7);
bloc++;
}
/* Receive one bit from the input file (buffered) */
static int huff_get_bit (qbyte *fin) {
int t;
t = (fin[(bloc>>3)] >> (bloc&7)) & 0x1;
bloc++;
return t;
}
static node_t **huff_get_ppnode(huff_t* huff) {
node_t **tppnode;
if (!huff->freelist) {
return &(huff->nodePtrs[huff->blocPtrs++]);
} else {
tppnode = huff->freelist;
huff->freelist = (node_t **)*tppnode;
return tppnode;
}
}
static void huff_free_ppnode(huff_t* huff, node_t **ppnode) {
*ppnode = (node_t *)huff->freelist;
huff->freelist = ppnode;
}
/* Swap the location of these two nodes in the tree */
static void huff_swap (huff_t* huff, node_t *node1, node_t *node2) {
node_t *par1, *par2;
par1 = node1->parent;
par2 = node2->parent;
if (par1) {
if (par1->left == node1) {
par1->left = node2;
} else {
par1->right = node2;
}
} else {
huff->tree = node2;
}
if (par2) {
if (par2->left == node2) {
par2->left = node1;
} else {
par2->right = node1;
}
} else {
huff->tree = node1;
}
node1->parent = par2;
node2->parent = par1;
}
/* Swap these two nodes in the linked list (update ranks) */
static void huff_swaplist(node_t *node1, node_t *node2) {
node_t *par1;
par1 = node1->next;
node1->next = node2->next;
node2->next = par1;
par1 = node1->prev;
node1->prev = node2->prev;
node2->prev = par1;
if (node1->next == node1) {
node1->next = node2;
}
if (node2->next == node2) {
node2->next = node1;
}
if (node1->next) {
node1->next->prev = node1;
}
if (node2->next) {
node2->next->prev = node2;
}
if (node1->prev) {
node1->prev->next = node1;
}
if (node2->prev) {
node2->prev->next = node2;
}
}
/* Do the increments */
static void huff_increment(huff_t* huff, node_t *node) {
node_t *lnode;
if (!node) {
return;
}
if (node->next != NULL && node->next->weight == node->weight) {
lnode = *node->head;
if (lnode != node->parent) {
huff_swap(huff, lnode, node);
}
huff_swaplist(lnode, node);
}
if (node->prev && node->prev->weight == node->weight) {
*node->head = node->prev;
} else {
*node->head = NULL;
huff_free_ppnode(huff, node->head);
}
node->weight++;
if (node->next && node->next->weight == node->weight) {
node->head = node->next->head;
} else {
node->head = huff_get_ppnode(huff);
*node->head = node;
}
if (node->parent) {
huff_increment(huff, node->parent);
if (node->prev == node->parent) {
huff_swaplist(node, node->parent);
if (*node->head == node) {
*node->head = node->parent;
}
}
}
}
static void Huff_addRef(huff_t* huff, qbyte ch) {
node_t *tnode, *tnode2;
if (huff->loc[ch] == NULL) { /* if this is the first transmission of this node */
tnode = &(huff->nodeList[huff->blocNode++]);
tnode2 = &(huff->nodeList[huff->blocNode++]);
tnode2->symbol = INTERNAL_NODE;
tnode2->weight = 1;
tnode2->next = huff->lhead->next;
if (huff->lhead->next) {
huff->lhead->next->prev = tnode2;
if (huff->lhead->next->weight == 1) {
tnode2->head = huff->lhead->next->head;
} else {
tnode2->head = huff_get_ppnode(huff);
*tnode2->head = tnode2;
}
} else {
tnode2->head = huff_get_ppnode(huff);
*tnode2->head = tnode2;
}
huff->lhead->next = tnode2;
tnode2->prev = huff->lhead;
tnode->symbol = ch;
tnode->weight = 1;
tnode->next = huff->lhead->next;
if (huff->lhead->next) {
huff->lhead->next->prev = tnode;
if (huff->lhead->next->weight == 1) {
tnode->head = huff->lhead->next->head;
} else {
/* this should never happen */
tnode->head = huff_get_ppnode(huff);
*tnode->head = tnode2;
}
} else {
/* this should never happen */
tnode->head = huff_get_ppnode(huff);
*tnode->head = tnode;
}
huff->lhead->next = tnode;
tnode->prev = huff->lhead;
tnode->left = tnode->right = NULL;
if (huff->lhead->parent) {
if (huff->lhead->parent->left == huff->lhead) { /* lhead is guaranteed to by the NYT */
huff->lhead->parent->left = tnode2;
} else {
huff->lhead->parent->right = tnode2;
}
} else {
huff->tree = tnode2;
}
tnode2->right = tnode;
tnode2->left = huff->lhead;
tnode2->parent = huff->lhead->parent;
huff->lhead->parent = tnode->parent = tnode2;
huff->loc[ch] = tnode;
huff_increment(huff, tnode2->parent);
} else {
huff_increment(huff, huff->loc[ch]);
}
}
/* Get a symbol */
static int Huff_Receive (node_t *node, int *ch, qbyte *fin) {
while (node && node->symbol == INTERNAL_NODE) {
if (huff_get_bit(fin)) {
node = node->right;
} else {
node = node->left;
}
}
if (!node) {
return 0;
// Com_Error(ERR_DROP, "Illegal tree!");
}
return (*ch = node->symbol);
}
/* Get a symbol */
static void Huff_offsetReceive (node_t *node, int *ch, qbyte *fin, int *offset) {
bloc = *offset;
while (node && node->symbol == INTERNAL_NODE) {
if (huff_get_bit(fin)) {
node = node->right;
} else {
node = node->left;
}
}
if (!node) {
*ch = 0;
return;
// Com_Error(ERR_DROP, "Illegal tree!");
}
*ch = node->symbol;
*offset = bloc;
}
/* Send the prefix code for this node */
static void huff_send(node_t *node, node_t *child, qbyte *fout) {
if (node->parent) {
huff_send(node->parent, node, fout);
}
if (child) {
if (node->right == child) {
huff_add_bit(1, fout);
} else {
huff_add_bit(0, fout);
}
}
}
/* Send a symbol */
static void Huff_transmit (huff_t *huff, int ch, qbyte *fout) {
int i;
if (huff->loc[ch] == NULL) {
/* node_t hasn't been transmitted, send a NYT, then the symbol */
Huff_transmit(huff, NYT, fout);
for (i = 7; i >= 0; i--) {
huff_add_bit((char)((ch >> i) & 0x1), fout);
}
} else {
huff_send(huff->loc[ch], NULL, fout);
}
}
static void Huff_offsetTransmit (huff_t *huff, int ch, qbyte *fout, int *offset) {
bloc = *offset;
huff_send(huff->loc[ch], NULL, fout);
*offset = bloc;
}
static void Huff_Decompress(sizebuf_t *mbuf, int offset) {
int ch, cch, i, j, size;
qbyte seq[65536];
qbyte* buffer;
huff_t huff;
size = mbuf->cursize - offset;
buffer = mbuf->data + offset;
if ( size <= 0 ) {
return;
}
memset(&huff, 0, sizeof(huff_t));
// Initialize the tree & list with the NYT node
huff.tree = huff.lhead = huff.ltail = huff.loc[NYT] = &(huff.nodeList[huff.blocNode++]);
huff.tree->symbol = NYT;
huff.tree->weight = 0;
huff.lhead->next = huff.lhead->prev = NULL;
huff.tree->parent = huff.tree->left = huff.tree->right = NULL;
cch = buffer[0]*256 + buffer[1];
// don't overflow with bad messages
if ( cch > mbuf->maxsize - offset ) {
cch = mbuf->maxsize - offset;
}
bloc = 16;
for ( j = 0; j < cch; j++ ) {
ch = 0;
// don't overflow reading from the messages
// FIXME: would it be better to have an overflow check in get_bit ?
if ( (bloc >> 3) > size ) {
seq[j] = 0;
break;
}
Huff_Receive(huff.tree, &ch, buffer); /* Get a character */
if ( ch == NYT ) { /* We got a NYT, get the symbol associated with it */
ch = 0;
for ( i = 0; i < 8; i++ ) {
ch = (ch<<1) + huff_get_bit(buffer);
}
}
seq[j] = ch; /* Write symbol */
Huff_addRef(&huff, (qbyte)ch); /* Increment node */
}
mbuf->cursize = cch + offset;
memcpy(mbuf->data + offset, seq, cch);
}
static void Huff_Compress(sizebuf_t *mbuf, int offset) {
int i, ch, size;
qbyte seq[65536];
qbyte* buffer;
huff_t huff;
size = mbuf->cursize - offset;
buffer = mbuf->data+ + offset;
if (size<=0) {
return;
}
memset(&huff, 0, sizeof(huff_t));
// Add the NYT (not yet transmitted) node into the tree/list */
huff.tree = huff.lhead = huff.loc[NYT] = &(huff.nodeList[huff.blocNode++]);
huff.tree->symbol = NYT;
huff.tree->weight = 0;
huff.lhead->next = huff.lhead->prev = NULL;
huff.tree->parent = huff.tree->left = huff.tree->right = NULL;
seq[0] = (size>>8);
seq[1] = size&0xff;
bloc = 16;
for (i=0; i<size; i++ ) {
ch = buffer[i];
Huff_transmit(&huff, ch, seq); /* Transmit symbol */
Huff_addRef(&huff, (qbyte)ch); /* Do update */
}
bloc += 8; // next byte
mbuf->cursize = (bloc>>3) + offset;
memcpy(mbuf->data+offset, seq, (bloc>>3));
}
static void Huff_Init(huffman_t *huff)
{
int i, j;
memset(&huff->compressor, 0, sizeof(huff_t));
memset(&huff->decompressor, 0, sizeof(huff_t));
// Initialize the tree & list with the NYT node
huff->decompressor.tree = huff->decompressor.lhead = huff->decompressor.ltail = huff->decompressor.loc[NYT] = &(huff->decompressor.nodeList[huff->decompressor.blocNode++]);
huff->decompressor.tree->symbol = NYT;
huff->decompressor.tree->weight = 0;
huff->decompressor.lhead->next = huff->decompressor.lhead->prev = NULL;
huff->decompressor.tree->parent = huff->decompressor.tree->left = huff->decompressor.tree->right = NULL;
// Add the NYT (not yet transmitted) node into the tree/list */
huff->compressor.tree = huff->compressor.lhead = huff->compressor.loc[NYT] = &(huff->compressor.nodeList[huff->compressor.blocNode++]);
huff->compressor.tree->symbol = NYT;
huff->compressor.tree->weight = 0;
huff->compressor.lhead->next = huff->compressor.lhead->prev = NULL;
huff->compressor.tree->parent = huff->compressor.tree->left = huff->compressor.tree->right = NULL;
for(i=0;i<256;i++)
{
for (j=0;j<huff->counts[i];j++)
{
Huff_addRef(&huff->compressor, (qbyte)i);
Huff_addRef(&huff->decompressor, (qbyte)i);
}
}
huff->built = true;
}
static huffman_t q3huff =
{
{
0x3D1CB, 0x0A0E9, 0x01894, 0x01BC2, 0x00E92, 0x00EA6, 0x017DE, 0x05AF3,
0x08225, 0x01B26, 0x01E9E, 0x025F2, 0x02429, 0x0436B, 0x00F6D, 0x006F2,
0x02060, 0x00644, 0x00636, 0x0067F, 0x0044C, 0x004BD, 0x004D6, 0x0046E,
0x006D5, 0x00423, 0x004DE, 0x0047D, 0x004F9, 0x01186, 0x00AF5, 0x00D90,
0x0553B, 0x00487, 0x00686, 0x0042A, 0x00413, 0x003F4, 0x0041D, 0x0042E,
0x006BE, 0x00378, 0x0049C, 0x00352, 0x003C0, 0x0030C, 0x006D8, 0x00CE0,
0x02986, 0x011A2, 0x016F9, 0x00A7D, 0x0122A, 0x00EFD, 0x0082D, 0x0074B,
0x00A18, 0x0079D, 0x007B4, 0x003AC, 0x0046E, 0x006FC, 0x00686, 0x004B6,
0x01657, 0x017F0, 0x01C36, 0x019FE, 0x00E7E, 0x00ED3, 0x005D4, 0x005F4,
0x008A7, 0x00474, 0x0054B, 0x003CB, 0x00884, 0x004E0, 0x00530, 0x004AB,
0x006EA, 0x00436, 0x004F0, 0x004F2, 0x00490, 0x003C5, 0x00483, 0x004A2,
0x00543, 0x004CC, 0x005F9, 0x00640, 0x00A39, 0x00800, 0x009F2, 0x00CCB,
0x0096A, 0x00E01, 0x009C8, 0x00AF0, 0x00A73, 0x01802, 0x00E4F, 0x00B18,
0x037AD, 0x00C5C, 0x008AD, 0x00697, 0x00C88, 0x00AB3, 0x00DB8, 0x012BC,
0x00FFB, 0x00DBB, 0x014A8, 0x00FB0, 0x01F01, 0x0178F, 0x014F0, 0x00F54,
0x0131C, 0x00E9F, 0x011D6, 0x012C7, 0x016DC, 0x01900, 0x01851, 0x02063,
0x05ACB, 0x01E9E, 0x01BA1, 0x022E7, 0x0153D, 0x01183, 0x00E39, 0x01488,
0x014C0, 0x014D0, 0x014FA, 0x00DA4, 0x0099A, 0x0069E, 0x0071D, 0x00849,
0x0077C, 0x0047D, 0x005EC, 0x00557, 0x004D4, 0x00405, 0x004EA, 0x00450,
0x004DD, 0x003EE, 0x0047D, 0x00401, 0x004D9, 0x003B8, 0x00507, 0x003E5,
0x006B1, 0x003F1, 0x004A3, 0x0036F, 0x0044B, 0x003A1, 0x00436, 0x003B7,
0x00678, 0x003A2, 0x00481, 0x00406, 0x004EE, 0x00426, 0x004BE, 0x00424,
0x00655, 0x003A2, 0x00452, 0x00390, 0x0040A, 0x0037C, 0x00486, 0x003DE,
0x00497, 0x00352, 0x00461, 0x00387, 0x0043F, 0x00398, 0x00478, 0x00420,
0x00D86, 0x008C0, 0x0112D, 0x02F68, 0x01E4E, 0x00541, 0x0051B, 0x00CCE,
0x0079E, 0x00376, 0x003FF, 0x00458, 0x00435, 0x00412, 0x00425, 0x0042F,
0x005CC, 0x003E9, 0x00448, 0x00393, 0x0041C, 0x003E3, 0x0042E, 0x0036C,
0x00457, 0x00353, 0x00423, 0x00325, 0x00458, 0x0039B, 0x0044F, 0x00331,
0x0076B, 0x00750, 0x003D0, 0x00349, 0x00467, 0x003BC, 0x00487, 0x003B6,
0x01E6F, 0x003BA, 0x00509, 0x003A5, 0x00467, 0x00C87, 0x003FC, 0x0039F,
0x0054B, 0x00300, 0x00410, 0x002E9, 0x003B8, 0x00325, 0x00431, 0x002E4,
0x003F5, 0x00325, 0x003F0, 0x0031C, 0x003E4, 0x00421, 0x02CC1, 0x034C0
},
0x286f2e8d
};
int Huff_PreferedCompressionCRC (void)
{
if (!net_compress.ival)
return 0;
return q3huff.crc;
}
huffman_t *Huff_CompressionCRC(int crc)
{
huffman_t *huff = NULL;
if (crc == q3huff.crc)
huff = &q3huff;
else
huff = NULL;
if (huff && !huff->built)
Huff_Init(huff);
return huff;
}
void Huff_DecryptPacket(sizebuf_t *msg, int offset)
{
//decompress using a dynamic from-nil tree
Huff_Decompress(msg, offset);
}
void Huff_EncryptPacket(sizebuf_t *msg, int offset)
{
//decompress using a dynamic from-nil tree
Huff_Compress(msg, offset);
}
int Huff_GetByte(qbyte *buffer, int *count)
{
int ch;
Huff_offsetReceive (q3huff.decompressor.tree, &ch, buffer, count);
return ch;
}
void Huff_EmitByte(int ch, qbyte *buffer, int *count)
{
Huff_offsetTransmit(&q3huff.compressor, ch, buffer, count);
}
void Huff_CompressPacket(huffman_t *huff, sizebuf_t *msg, int offset)
{
qbyte buffer[MAX_OVERALLMSGLEN];
qbyte *data;
int outLen;
int inLen;
int i;
data = msg->data + offset;
inLen = msg->cursize - offset;
if (inLen <= 0 || inLen >= MAX_OVERALLMSGLEN)
{
//panic!
return;
}
outLen = 0;
for (i=0; i < inLen; i++)
{
Huff_offsetTransmit(&huff->compressor, data[i], buffer, &outLen);
if (outLen > inLen)
break;
if (outLen > MAX_OVERALLMSGLEN-64)
{
Con_Printf("Huffman overflow\n");
//panic
data[0] = 0x80;
msg->cursize = offset+1;
return;
}
}
if (outLen > inLen)
{
memmove(data+1, data, inLen);
data[0] = 0x80; //this would have grown the packet.
msg->cursize+=1;
return; //cap it at only 1 qbyte growth.
}
msg->cursize = offset + outLen;
{ //add the bitcount
data[0] = (outLen<<3) - outLen;
data+=1;
msg->cursize+=1;
}
if (msg->cursize > msg->maxsize)
Sys_Error("Compression became too large\n");
memcpy(data, buffer, outLen);
}
void Huff_DecompressPacket(huffman_t *huff, sizebuf_t *msg, int offset)
{
qbyte buffer[MAX_OVERALLMSGLEN];
qbyte *data;
int outLen;
int inLen;
int i, ch;
data = msg->data + offset;
inLen = msg->cursize - offset;
if (inLen <= 0 || inLen >= MAX_OVERALLMSGLEN)
{
return;
}
inLen<<=3;
{ //add the bitcount
inLen = inLen-8-data[0];
if (data[0]&0x80)
{ //packet would have grown.
msg->cursize -= 1;
memmove(data, data+1, msg->cursize);
return; //this never happened, okay?
}
data+=1;
}
outLen = 0;
for(i=0; outLen < inLen; i++)
{
if (i == MAX_OVERALLMSGLEN)
Sys_Error("Decompression became too large\n");
Huff_offsetReceive (huff->decompressor.tree, &ch, data, &outLen);
buffer[i] = ch;
}
msg->cursize = offset + i;
if (msg->cursize > msg->maxsize)
Sys_Error("Decompression became too large\n");
memcpy(msg->data + offset, buffer, i);
}
#endif
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