* Branch upstream ioq3-r437 into trunk

1 files changed, 437 insertions, 0 deletions

diff --git a/ioq3-r437/src/qcommon/huffman.c b/ioq3-r437/src/qcommon/huffman.c
new file mode 100644
index 00000000..b230b5be
--- /dev/null
+++ b/ioq3-r437/src/qcommon/huffman.c
@@ -0,0 +1,437 @@
+/*
+===========================================================================
+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 "q_shared.h"
+#include "qcommon.h"
+
+static int			bloc = 0;
+
+void	Huff_putBit( int bit, byte *fout, int *offset) {
+	bloc = *offset;
+	if ((bloc&7) == 0) {
+		fout[(bloc>>3)] = 0;
+	}
+	fout[(bloc>>3)] |= bit << (bloc&7);
+	bloc++;
+	*offset = bloc;
+}
+
+int		Huff_getBit( byte *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 add_bit (char bit, byte *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 get_bit (byte *fin) {
+	int t;
+	t = (fin[(bloc>>3)] >> (bloc&7)) & 0x1;
+	bloc++;
+	return t;
+}
+
+static node_t **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 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 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 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 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) {
+			swap(huff, lnode, node);
+		}
+		swaplist(lnode, node);
+	}
+	if (node->prev && node->prev->weight == node->weight) {
+		*node->head = node->prev;
+	} else {
+	    *node->head = NULL;
+		free_ppnode(huff, node->head);
+	}
+	node->weight++;
+	if (node->next && node->next->weight == node->weight) {
+		node->head = node->next->head;
+	} else { 
+		node->head = get_ppnode(huff);
+		*node->head = node;
+	}
+	if (node->parent) {
+		increment(huff, node->parent);
+		if (node->prev == node->parent) {
+			swaplist(node, node->parent);
+			if (*node->head == node) {
+				*node->head = node->parent;
+			}
+		}
+	}
+}
+
+void Huff_addRef(huff_t* huff, byte 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 = get_ppnode(huff);
+				*tnode2->head = tnode2;
+			}
+		} else {
+			tnode2->head = 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 = get_ppnode(huff);
+				*tnode->head = tnode2;
+		    }
+		} else {
+			/* this should never happen */
+			tnode->head = 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;
+ 
+		increment(huff, tnode2->parent);
+	} else {
+		increment(huff, huff->loc[ch]);
+	}
+}
+
+/* Get a symbol */
+int Huff_Receive (node_t *node, int *ch, byte *fin) {
+	while (node && node->symbol == INTERNAL_NODE) {
+		if (get_bit(fin)) {
+			node = node->right;
+		} else {
+			node = node->left;
+		}
+	}
+	if (!node) {
+		return 0;
+//		Com_Error(ERR_DROP, "Illegal tree!\n");
+	}
+	return (*ch = node->symbol);
+}
+
+/* Get a symbol */
+void Huff_offsetReceive (node_t *node, int *ch, byte *fin, int *offset) {
+	bloc = *offset;
+	while (node && node->symbol == INTERNAL_NODE) {
+		if (get_bit(fin)) {
+			node = node->right;
+		} else {
+			node = node->left;
+		}
+	}
+	if (!node) {
+		*ch = 0;
+		return;
+//		Com_Error(ERR_DROP, "Illegal tree!\n");
+	}
+	*ch = node->symbol;
+	*offset = bloc;
+}
+
+/* Send the prefix code for this node */
+static void send(node_t *node, node_t *child, byte *fout) {
+	if (node->parent) {
+		send(node->parent, node, fout);
+	}
+	if (child) {
+		if (node->right == child) {
+			add_bit(1, fout);
+		} else {
+			add_bit(0, fout);
+		}
+	}
+}
+
+/* Send a symbol */
+void Huff_transmit (huff_t *huff, int ch, byte *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--) {
+			add_bit((char)((ch >> i) & 0x1), fout);
+		}
+	} else {
+		send(huff->loc[ch], NULL, fout);
+	}
+}
+
+void Huff_offsetTransmit (huff_t *huff, int ch, byte *fout, int *offset) {
+	bloc = *offset;
+	send(huff->loc[ch], NULL, fout);
+	*offset = bloc;
+}
+
+void Huff_Decompress(msg_t *mbuf, int offset) {
+	int			ch, cch, i, j, size;
+	byte		seq[65536];
+	byte*		buffer;
+	huff_t		huff;
+
+	size = mbuf->cursize - offset;
+	buffer = mbuf->data + offset;
+
+	if ( size <= 0 ) {
+		return;
+	}
+
+	Com_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 a 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) + get_bit(buffer);
+			}
+		}
+    
+		seq[j] = ch;									/* Write symbol */
+
+		Huff_addRef(&huff, (byte)ch);								/* Increment node */
+	}
+	mbuf->cursize = cch + offset;
+	Com_Memcpy(mbuf->data + offset, seq, cch);
+}
+
+extern 	int oldsize;
+
+void Huff_Compress(msg_t *mbuf, int offset) {
+	int			i, ch, size;
+	byte		seq[65536];
+	byte*		buffer;
+	huff_t		huff;
+
+	size = mbuf->cursize - offset;
+	buffer = mbuf->data+ + offset;
+
+	if (size<=0) {
+		return;
+	}
+
+	Com_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;
+	huff.loc[NYT] = huff.tree;
+
+	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, (byte)ch);								/* Do update */
+	}
+
+	bloc += 8;												// next byte
+
+	mbuf->cursize = (bloc>>3) + offset;
+	Com_Memcpy(mbuf->data+offset, seq, (bloc>>3));
+}
+
+void Huff_Init(huffman_t *huff) {
+
+	Com_Memset(&huff->compressor, 0, sizeof(huff_t));
+	Com_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;
+	huff->compressor.loc[NYT] = huff->compressor.tree;
+}
+