1 files changed, 110 insertions, 0 deletions
diff --git a/indra/llmessage/llregionhandle.h b/indra/llmessage/llregionhandle.h
new file mode 100644
index 0000000000..41d104231c
--- /dev/null
+++ b/indra/llmessage/llregionhandle.h
@@ -0,0 +1,110 @@
+/** 
+ * @file llregionhandle.h
+ * @brief Routines for converting positions to/from region handles.
+ *
+ * Copyright (c) 2002-$CurrentYear$, Linden Research, Inc.
+ * $License$
+ */
+
+#ifndef LL_LLREGIONHANDLE_H
+#define LL_LLREGIONHANDLE_H
+
+#include <math.h>
+
+#include "indra_constants.h"
+#include "v3math.h"
+#include "v3dmath.h"
+
+inline U64 to_region_handle(const U32 x_origin, const U32 y_origin)
+{
+	U64 region_handle;
+	region_handle =  ((U64)x_origin) << 32;
+	region_handle |= (U64) y_origin;
+	return region_handle;
+}
+
+inline U64 to_region_handle(const LLVector3d& pos_global)
+{
+	U32 global_x = (U32)pos_global.mdV[VX];
+	global_x -= global_x % 256;
+
+	U32 global_y = (U32)pos_global.mdV[VY];
+	global_y -= global_y % 256;
+
+	return to_region_handle(global_x, global_y);
+}
+
+inline U64 to_region_handle_global(const F32 x_global, const F32 y_global)
+{
+	// Round down to the nearest origin
+	U32 x_origin = (U32)x_global;
+	x_origin -= x_origin % REGION_WIDTH_U32;
+	U32 y_origin = (U32)y_global;
+	y_origin -= y_origin % REGION_WIDTH_U32;
+	U64 region_handle;
+	region_handle =  ((U64)x_origin) << 32;
+	region_handle |= (U64) y_origin;
+	return region_handle;
+}
+
+inline BOOL to_region_handle(const F32 x_pos, const F32 y_pos, U64 *region_handle)
+{
+	U32 x_int, y_int;
+	if (x_pos < 0.f)
+	{
+//		llwarns << "to_region_handle:Clamping negative x position " << x_pos << " to zero!" << llendl;
+		return FALSE;
+	}
+	else
+	{
+		x_int = (U32)llround(x_pos);
+	}
+	if (y_pos < 0.f)
+	{
+//		llwarns << "to_region_handle:Clamping negative y position " << y_pos << " to zero!" << llendl;
+		return FALSE;
+	}
+	else
+	{
+		y_int = (U32)llround(y_pos);
+	}
+	*region_handle = to_region_handle(x_int, y_int);
+	return TRUE;
+}
+
+// stuff the word-frame XY location of sim's SouthWest corner in x_pos, y_pos
+inline void from_region_handle(const U64 &region_handle, F32 *x_pos, F32 *y_pos)
+{
+	*x_pos = (F32)((U32)(region_handle >> 32));
+	*y_pos = (F32)((U32)(region_handle & 0xFFFFFFFF));
+}
+
+// stuff the word-frame XY location of sim's SouthWest corner in x_pos, y_pos
+inline void from_region_handle(const U64 &region_handle, U32 *x_pos, U32 *y_pos)
+{
+	*x_pos = ((U32)(region_handle >> 32));
+	*y_pos = ((U32)(region_handle & 0xFFFFFFFF));
+}
+
+// return the word-frame XY location of sim's SouthWest corner in LLVector3d
+inline LLVector3d from_region_handle(const U64 &region_handle)
+{
+	return LLVector3d(((U32)(region_handle >> 32)), (U32)(region_handle & 0xFFFFFFFF), 0.f);
+}
+
+// grid-based region handle encoding. pass in a grid position
+// (eg: 1000,1000) and this will return the region handle.
+inline U64 grid_to_region_handle(U32 grid_x, U32 grid_y)
+{
+	return to_region_handle(grid_x * REGION_WIDTH_UNITS,
+							grid_y * REGION_WIDTH_UNITS);
+}
+
+inline void grid_from_region_handle(const U64& region_handle, U32* grid_x, U32* grid_y)
+{
+	from_region_handle(region_handle, grid_x, grid_y);
+	*grid_x /= REGION_WIDTH_UNITS;
+	*grid_y /= REGION_WIDTH_UNITS;
+}
+	
+#endif