--- /dev/null
+/*!@file
+ \brief HENGE Memory Definition in common with STON Asset Packages
+ \details C Aligned memory structures used to define datatypes in the STON
+ Asset Package format, used for reading asset packages as runtime
+ memory.
+ \author Ken Grimes
+ \date Feb 2017
+ ----------------------------------------------------------------------------*/
+#ifndef _HENGE_H_
+#define _HENGE_H_
+
+/* Henge Generic Hashtable
+
+ Hashtables are stored as dynamically sized two dimensional arrays, whose
+ columns are provided, and whose rows, and sizes, are derived.
+
+ ht_size = header.ht_columns << header.ht_2pow;
+ ht_rows = 0x1 << header.ht_2pow;
+
+ All generic hashtables in henge must have a power-of-two number of rows. An
+ ht_columns value that is also a power-of-two will result in a power-of-two
+ sized memory imprint for the structure, making it easy to page align.
+
+ Elements in the columns may be of any arbitrary size.
+
+ typedef uint32_t my_ht_type;
+ ht_bytes = ht_size * sizeof(my_ht_type);
+*/
+struct hng_ht_header_t
+{ uint16_t ht_columns;
+ uint8_t ht_2pow, ht_flags;
+};
+
+#define hng_ht_size(_HEADER) ((_HEADER)->ht_columns << (_HEADER)->ht_2pow)
+#define hng_ht_rows(_HEADER) (0x1 << (_HEADER)->ht_2pow)
+#define hng_ht_cols(_HEADER) (_HEADER->ht_columns)
+#define hng_ht_start(_HEADER) (_HEADER + sizeof(*_HEADER))
+#define hng_ht_array(_HEADER,_UNIT) ((_UNIT*)hng_ht_start(_HEADER))
+#define hng_ht_bytes(_HEADER,_UNIT) (hng_ht_size(_HEADER) * sizeof(_UNIT))
+#define hng_ht_2bytes(_HEADER,_UNIT2POW) (hng_ht_size(_HEADER) << _UNIT2POW)
+
+#endif //_HENGE_H_