0497adffcf
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@29927 a1c6a512-1295-4272-9138-f99709370657
49 lines
1.9 KiB
C
49 lines
1.9 KiB
C
/***************************************************************************
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* __________ __ ___.
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* Open \______ \ ____ ____ | | _\_ |__ _______ ___
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* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
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* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
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* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
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* \/ \/ \/ \/ \/
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* $Id$
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*
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* Copyright (C) 2006 Jens Arnold
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*
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* Fixed point library for plugins
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
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* KIND, either express or implied.
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*
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****************************************************************************/
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/** CODECS - FIXED POINT MATH ROUTINES - USAGE
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*
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* - x and y arguments are fixed point integers
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* - fracbits is the number of fractional bits in the argument(s)
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* - functions return long fixed point integers with the specified number
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* of fractional bits unless otherwise specified
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*
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* Calculate sin and cos of an angle:
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* fp_sincos(phase, *cos)
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* where phase is a 32 bit unsigned integer with 0 representing 0
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* and 0xFFFFFFFF representing 2*pi, and *cos is the address to
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* a long signed integer. Value returned is a long signed integer
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* from -0x80000000 to 0x7fffffff, representing -1 to 1 respectively.
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* That is, value is a fixed point integer with 31 fractional bits.
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*
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* Take square root of a fixed point number:
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* fp_sqrt(x, fracbits)
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*
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*/
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#ifndef _FIXEDPOINT_H_CODECS
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#define _FIXEDPOINT_H_CODECS
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long fp_sincos(unsigned long phase, long *cos);
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long fp_sqrt(long a, unsigned int fracbits);
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#endif
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