1 files changed, 59 insertions, 0 deletions
diff --git a/src/qcommon/huffman.h b/src/qcommon/huffman.h
new file mode 100644
index 0000000..217fb9f
--- /dev/null
+++ b/src/qcommon/huffman.h
@@ -0,0 +1,59 @@
+#ifndef QCOMMON_HUFFMAN_H
+#define QCOMMON_HUFFMAN_H 1
+
+#include <stdint.h>
+
+/* 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 */
+
+#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;
+
+typedef struct {
+    huff_t compressor;
+    huff_t decompressor;
+} huffman_t;
+
+void Huff_Compress(struct msg_t *buf, int offset);
+void Huff_Decompress(struct msg_t *buf, int offset);
+void Huff_Init(huffman_t *huff);
+void Huff_addRef(huff_t *huff, uint8_t ch);
+int Huff_Receive(node_t *node, int *ch, uint8_t *fin);
+void Huff_transmit(huff_t *huff, int ch, uint8_t *fout, int maxoffset);
+void Huff_offsetReceive(node_t *node, int *ch, uint8_t *fin, int *offset, int maxoffset);
+void Huff_offsetTransmit(huff_t *huff, int ch, uint8_t *fout, int *offset, int maxoffset);
+void Huff_putBit(int bit, uint8_t *fout, int *offset);
+int Huff_getBit(uint8_t *fout, int *offset);
+
+// don't use if you don't know what you're doing.
+int Huff_getBloc(void);
+void Huff_setBloc(int _bloc);
+
+extern huffman_t clientHuffTables;
+
+#endif