X-Git-Url: https://git.pterodactylus.net/?a=blobdiff_plain;f=synfig-core%2Fsrc%2Fsynfig%2Fquick_rng.h;fp=synfig-core%2Fsrc%2Fsynfig%2Fquick_rng.h;h=3924cef1fb755c0e6b7f8754f6cf34cfdee3d901;hb=a095981e18cc37a8ecc7cd237cc22b9c10329264;hp=0000000000000000000000000000000000000000;hpb=9459638ad6797b8139f1e9f0715c96076dbf0890;p=synfig.git

diff --git a/synfig-core/src/synfig/quick_rng.h b/synfig-core/src/synfig/quick_rng.h
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+/* === S Y N F I G ========================================================= */
+/*!	\file quick_rng.h
+**	\brief Template Header
+**
+**	$Id$
+**
+**	\legal
+**	Copyright (c) 2002-2005 Robert B. Quattlebaum Jr., Adrian Bentley
+**	Copyright (c) 2007 Chris Moore
+**
+**	This package is free software; you can redistribute it and/or
+**	modify it under the terms of the GNU General Public License as
+**	published by the Free Software Foundation; either version 2 of
+**	the License, or (at your option) any later version.
+**
+**	This package 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
+**	General Public License for more details.
+**	\endlegal
+*/
+/* ========================================================================= */
+
+/* === S T A R T =========================================================== */
+
+#ifndef __SYNFIG_QUICK_RNG_H
+#define __SYNFIG_QUICK_RNG_H
+
+/* === H E A D E R S ======================================================= */
+
+#include <stdint.h>
+
+/* === M A C R O S ========================================================= */
+
+/* === T Y P E D E F S ===================================================== */
+
+/* === C L A S S E S & S T R U C T S ======================================= */
+
+// A fast 32-bit linear congruential random number generator
+class quick_rng
+{
+	uint32_t next;
+public:
+	quick_rng(uint32_t seed=0):next(seed) { }
+
+	void set_seed(uint32_t x)
+	{
+		next=x;
+	}
+
+	uint32_t i32()
+	{
+		static const uint32_t a(1664525);
+		static const uint32_t c(1013904223);
+
+		return next=next*a+c;
+	}
+
+	uint32_t i16()
+	{
+		return i32()>>16;
+	}
+
+	float f()
+	{
+		static const float m(int(65535));
+
+		return float(i16())/m;
+	}
+
+	uint32_t operator()(const uint32_t& m)
+	{
+		if(m==65536)
+			return i16();
+		else
+		if(m<=65536)
+			return i16()%m;
+		else
+			return i32()%m;
+	}
+};
+
+/* === E N D =============================================================== */
+
+#endif