- moved most utility code to a subdirectory.

Again no code changes.

src/utility/math/fastsin.cpp

@@ -0,0 +1,106 @@
+/*
+** fastsin.cpp
+** a table/linear interpolation-based sine function that is both 
+** precise and fast enough for most purposes.
+**
+**---------------------------------------------------------------------------
+** Copyright 2015 Christoph Oelckers
+** All rights reserved.
+**
+** Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions
+** are met:
+**
+** 1. Redistributions of source code must retain the above copyright
+**    notice, this list of conditions and the following disclaimer.
+** 2. Redistributions in binary form must reproduce the above copyright
+**    notice, this list of conditions and the following disclaimer in the
+**    documentation and/or other materials provided with the distribution.
+** 3. The name of the author may not be used to endorse or promote products
+**    derived from this software without specific prior written permission.
+**
+** THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+** OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+** IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+** NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+** THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+**---------------------------------------------------------------------------
+**
+*/
+
+#include <math.h>
+#include "cmath.h"
+
+
+#ifndef M_PI
+#define M_PI 3.14159265358979323846
+#endif
+
+FFastTrig fasttrig;
+
+FFastTrig::FFastTrig()
+{
+	const double pimul = M_PI * 2 / TBLPERIOD;
+
+	for (int i = 0; i < 2049; i++)
+	{
+		sinetable[i] = (float)c_sin(i*pimul);
+	}
+}
+
+__forceinline double FFastTrig::sinq1(unsigned bangle)
+{
+	unsigned int index = bangle >> BITSHIFT;
+
+	if ((bangle &= (REMAINDER)) == 0)	// This is to avoid precision problems at 180°
+	{
+		return double(sinetable[index]);
+	}
+	else
+	{
+		return (double(sinetable[index]) * (REMAINDER - bangle) + double(sinetable[index + 1]) * bangle) * (1. / REMAINDER);
+	}
+}
+
+double FFastTrig::sin(unsigned bangle)
+{
+	switch (bangle & 0xc0000000)
+	{
+	default:
+		return sinq1(bangle);
+
+	case 0x40000000:
+		return sinq1(0x80000000 - bangle);
+
+	case 0x80000000:
+		return -sinq1(bangle - 0x80000000);
+
+	case 0xc0000000:
+		return -sinq1(0 - bangle);
+	}
+}
+
+
+double FFastTrig::cos(unsigned bangle)
+{
+	switch (bangle & 0xc0000000)
+	{
+	default:
+		return sinq1(0x40000000 - bangle);
+
+	case 0x40000000:
+		return -sinq1(bangle - 0x40000000);
+
+	case 0x80000000:
+		return -sinq1(0xc0000000 - bangle);
+
+	case 0xc0000000:
+		return sinq1(bangle - 0xc0000000);
+	}
+}
+