#ifndef fixed_h #define fixed_h /* fixed.h */ /* avr.math.fixed - Fixed point math module. {{{ * * Copyright (C) 2005 Nicolas Schodet * * Robot APB Team/Efrei 2006. * Web: http://assos.efrei.fr/robot/ * Email: robot AT efrei DOT fr * * This program 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 program 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. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * * }}} */ /* Numbers notation: * [u]{i|f}x[.y] * u: unsigned * i: integer * f: fixed point * x: integral part size in bits * y: fractionnal part size in bits * * Ex: i16: signed 16 bit word, uf8.8: unsigned fixed 8.8. * * Angles are mapped from [0, 2pi) to [0,1). */ #ifndef HOST /* Multiply f8.24 by f8.24, return f8.24. */ #define fixed_mul_f824(a, b) ({ \ uint16_t dummy; \ asm ("" : "=r" (dummy)); \ fixed_mul_f824_asm (dummy, a, b); }) int32_t fixed_mul_f824_asm (uint16_t dummy, int32_t a, int32_t b); /* Divide f8.24 by f8.24, return f8.24. */ int32_t fixed_div_f824 (int32_t a, int32_t b); #else /* HOST */ /** Multiply f8.24 by f8.24, return f8.24. */ #define fixed_mul_f824(a, b) \ (((int64_t) (int32_t) (a) * (int64_t) (int32_t) (b) \ + 0x800000LL) >> 24) /** Divide f8.24 by f8.24, return f8.24. */ #define fixed_div_f824(a, b) \ (((int64_t) (int32_t) (a) << 24) / (int64_t) (int32_t) (b)) #endif /** Compute cosinus, angle f8.24, result f8.24. */ int32_t fixed_cos_f824 (int32_t a); /** Compute sinus, angle f8.24, result f8.24. */ int32_t fixed_sin_f824 (int32_t a); /** Compute square root, uf24.8. */ uint32_t fixed_sqrt_uf248 (uint32_t x); /** Compute square root, ui32 -> ui16. */ uint16_t fixed_sqrt_ui32 (uint32_t x); #endif /* fixed_h */