Add PAK methods 10 (crush) and 11 (distill).

pak/prefixcode.h

@@ -0,0 +1,89 @@
+/*
+ * prefixcode.h - Prefix code tree implementation
+ *
+ * Copyright (c) 2017-present, MacPaw Inc. All rights reserved.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301  USA
+ */
+
+#ifndef PREFIXCODE_H
+#define PREFIXCODE_H
+
+#include <stdbool.h>
+#include <stdint.h>
+#include "bitstream.h"
+
+// Error codes
+#define PREFIX_CODE_OK      0
+#define PREFIX_CODE_INVALID -1
+
+typedef struct CodeTreeNode
+{
+    int branches[2];
+} CodeTreeNode;
+
+typedef struct CodeTableEntry
+{
+    uint32_t length;
+    int32_t  value;
+} CodeTableEntry;
+
+// Simple stack implementation for tree building
+typedef struct PrefixCodeStack
+{
+    int *data;
+    int  count;
+    int  capacity;
+} PrefixCodeStack;
+
+typedef struct PrefixCode
+{
+    CodeTreeNode *tree;
+    int           numentries;
+    int           minlength;
+    int           maxlength;
+    bool          isstatic;
+
+    int              currnode;
+    PrefixCodeStack *stack;
+
+    int             tablesize;
+    CodeTableEntry *table1;
+    CodeTableEntry *table2;
+} PrefixCode;
+
+// Function declarations
+PrefixCode *prefix_code_alloc(void);
+PrefixCode *prefix_code_alloc_with_lengths(const int *lengths, int numsymbols, int maxlength, bool shortestCodeIsZeros);
+PrefixCode *prefix_code_alloc_with_static_table(int (*statictable)[2]);
+void        prefix_code_free(PrefixCode *self);
+
+int prefix_code_add_value_high_bit_first(PrefixCode *self, int value, uint32_t code, int length);
+int prefix_code_add_value_high_bit_first_repeat(PrefixCode *self, int value, uint32_t code, int length, int repeatpos);
+int prefix_code_add_value_low_bit_first(PrefixCode *self, int value, uint32_t code, int length);
+int prefix_code_add_value_low_bit_first_repeat(PrefixCode *self, int value, uint32_t code, int length, int repeatpos);
+
+void prefix_code_start_building_tree(PrefixCode *self);
+void prefix_code_start_zero_branch(PrefixCode *self);
+void prefix_code_start_one_branch(PrefixCode *self);
+void prefix_code_finish_branches(PrefixCode *self);
+void prefix_code_make_leaf_with_value(PrefixCode *self, int value);
+
+// BitStream interface functions
+int prefix_code_read_symbol(BitStream *bs, PrefixCode *code);
+int prefix_code_read_symbol_le(BitStream *bs, PrefixCode *code);
+
+#endif /* PREFIXCODE_H */