Moved radixsort out of bgfx.

include/bx/radixsort.h

@@ -0,0 +1,111 @@
+/*
+ * Copyright 2010-2011 Branimir Karadzic. All rights reserved.
+ * License: http://www.opensource.org/licenses/BSD-2-Clause
+ */
+
+#ifndef __BX_RADIXSORT_H__
+#define __BX_RADIXSORT_H__
+
+#include "bx.h"
+
+namespace bx
+{
+#define BX_RADIXSORT_BITS 11
+#define BX_RADIXSORT_HISTOGRAM_SIZE (1<<BX_RADIXSORT_BITS)
+#define BX_RADIXSORT_BIT_MASK (BX_RADIXSORT_HISTOGRAM_SIZE-1)
+
+	template <typename Ty>
+	void radixSort32(uint32_t* _keys, uint32_t* _tempKeys, Ty* _values, Ty* _tempValues, uint32_t _size)
+	{
+		uint16_t histogram[BX_RADIXSORT_HISTOGRAM_SIZE];
+		uint16_t shift = 0;
+		for (uint32_t pass = 0; pass < 3; ++pass)
+		{
+			memset(histogram, 0, sizeof(uint16_t)*BX_RADIXSORT_HISTOGRAM_SIZE);
+			for (uint32_t ii = 0; ii < _size; ++ii)
+			{
+				uint32_t key = _keys[ii];
+				uint16_t index = (key>>shift)&BX_RADIXSORT_BIT_MASK;
+				++histogram[index];
+			}
+
+			uint16_t offset = 0;
+			for (uint32_t ii = 0; ii < BX_RADIXSORT_HISTOGRAM_SIZE; ++ii)
+			{
+				uint16_t count = histogram[ii];
+				histogram[ii] = offset;
+				offset += count;
+			}
+
+			for (uint32_t ii = 0; ii < _size; ++ii)
+			{
+				uint32_t key = _keys[ii];
+				uint16_t index = (key>>shift)&BX_RADIXSORT_BIT_MASK;
+				uint16_t dest = histogram[index]++;
+				_tempKeys[dest] = key;
+				_tempValues[dest] = _values[ii];
+			}
+
+			uint32_t* swapKeys = _tempKeys;
+			_tempKeys = _keys;
+			_keys = swapKeys;
+
+			Ty* swapValues = _tempValues;
+			_tempValues = _values;
+			_values = swapValues;
+
+			shift += BX_RADIXSORT_BITS;
+		}
+	}
+
+	template <typename Ty>
+	void radixSort64(uint64_t* _keys, uint64_t* _tempKeys, Ty* _values, Ty* _tempValues, uint32_t _size)
+	{
+		uint16_t histogram[BX_RADIXSORT_HISTOGRAM_SIZE];
+		uint16_t shift = 0;
+		for (uint32_t pass = 0; pass < 6; ++pass)
+		{
+			memset(histogram, 0, sizeof(uint16_t)*BX_RADIXSORT_HISTOGRAM_SIZE);
+			for (uint32_t ii = 0; ii < _size; ++ii)
+			{
+				uint64_t key = _keys[ii];
+				uint16_t index = (key>>shift)&BX_RADIXSORT_BIT_MASK;
+				++histogram[index];
+			}
+
+			uint16_t offset = 0;
+			for (uint32_t ii = 0; ii < BX_RADIXSORT_HISTOGRAM_SIZE; ++ii)
+			{
+				uint16_t count = histogram[ii];
+				histogram[ii] = offset;
+				offset += count;
+			}
+
+			for (uint32_t ii = 0; ii < _size; ++ii)
+			{
+				uint64_t key = _keys[ii];
+				uint16_t index = (key>>shift)&BX_RADIXSORT_BIT_MASK;
+				uint16_t dest = histogram[index]++;
+				_tempKeys[dest] = key;
+				_tempValues[dest] = _values[ii];
+			}
+
+			uint64_t* swapKeys = _tempKeys;
+			_tempKeys = _keys;
+			_keys = swapKeys;
+
+			Ty* swapValues = _tempValues;
+			_tempValues = _values;
+			_values = swapValues;
+
+			shift += BX_RADIXSORT_BITS;
+		}
+	}
+
+#undef BX_RADIXSORT_BITS
+#undef BX_RADIXSORT_HISTOGRAM_SIZE
+#undef BX_RADIXSORT_BIT_MASK
+
+} // namespace bx
+
+#endif // __BX_RADIXSORT_H__