Restructuring of code

code/external/libsmacker/smk_hufftree.h

@@ -0,0 +1,104 @@
+/*
+	libsmacker - A C library for decoding .smk Smacker Video files
+	Copyright (C) 2012-2013 Greg Kennedy
+
+	See smacker.h for more information.
+
+	smk_hufftree.h
+		SMK huffmann trees.  There are two types:
+		- a basic 8-bit tree, and
+		- a "big" 16-bit tree which includes a cache for recently
+			searched values.
+*/
+
+#ifndef SMK_HUFFTREE_H
+#define SMK_HUFFTREE_H
+
+#include "smk_bitstream.h"
+
+/*
+	Tree node structure.
+	If b0 is non-null, this is a branch, and b1 from the union should be used.
+	If b0 is null, this is a leaf, and val / escape code from union should be used.
+*/
+struct smk_huff_t
+{
+	struct smk_huff_t *b0;
+	union
+	{
+		struct smk_huff_t *b1;
+		struct
+		{
+			unsigned short value;
+			unsigned char escapecode;
+		} leaf;
+	} u;
+};
+
+/*
+	"Big"tree struct: holds a huff_t structure,
+	as well as a cache of three 16-bit values.
+*/
+struct smk_huff_big_t
+{
+	struct smk_huff_t *t;
+	unsigned short cache[3];
+};
+
+/* function to recursively delete a huffman tree */
+void smk_huff_free(struct smk_huff_t *);
+
+/* This macro interrogates return code from smk_huff_lookup and
+	jumps to error label if problems occur. */
+#define smk_huff_safe_build(bs,t) \
+{ \
+	if (!(t = smk_huff_build(bs))) \
+	{ \
+		fprintf(stderr,"libsmacker::smk_huff_safe_build(" #bs "," #t ") - ERROR (file: %s, line: %lu)\n", __FILE__, (unsigned long)__LINE__); \
+		goto error; \
+	} \
+}
+/* Build a tree from a bitstream */
+struct smk_huff_t *smk_huff_build(struct smk_bit_t *);
+
+/* This macro interrogates return code from smk_huff_lookup and
+	jumps to error label if problems occur. */
+#define smk_huff_safe_lookup(bs,t,s) \
+{ \
+	if ((short)(s = smk_huff_lookup(bs,t)) < 0) \
+	{ \
+		fprintf(stderr,"libsmacker::smk_huff_safe_lookup(" #bs "," #t "," #s ") - ERROR (file: %s, line: %lu)\n", __FILE__, (unsigned long)__LINE__); \
+		goto error; \
+	} \
+}
+/* Look up an 8-bit value in the referenced tree by following a bitstream
+	returns -1 on error */
+short smk_huff_lookup (struct smk_bit_t *, const struct smk_huff_t *);
+
+#define smk_huff_big_safe_build(bs,t) \
+{ \
+	if (!(t = smk_huff_big_build(bs))) \
+	{ \
+		fprintf(stderr,"libsmacker::smk_huff_big_safe_build(" #bs "," #t ") - ERROR (file: %s, line: %lu)\n", __FILE__, (unsigned long)__LINE__); \
+		goto error; \
+	} \
+}
+/* Build a bigtree from a bitstream */
+struct smk_huff_big_t *smk_huff_big_build(struct smk_bit_t *);
+
+#define smk_huff_big_safe_lookup(bs,t,s) \
+{ \
+	if ((s = smk_huff_big_lookup(bs,t)) < 0) \
+	{ \
+		fprintf(stderr,"libsmacker::smk_huff_big_safe_lookup(" #bs "," #t "," #s ") - ERROR (file: %s, line: %lu)\n", __FILE__, (unsigned long)__LINE__); \
+		goto error; \
+	} \
+}
+/* Look up a 16-bit value in the bigtree by following a bitstream
+	returns -1 on error */
+long smk_huff_big_lookup (struct smk_bit_t *, struct smk_huff_big_t *);
+
+/* Reset the cache in a bigtree */
+void smk_huff_big_reset (struct smk_huff_big_t *);
+
+#endif