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* libcaca ASCII-Art library
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* Copyright (c) 2002, 2003 Sam Hocevar <sam@zoy.org>
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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* \version \$Id: math.c 195 2003-12-31 14:21:08Z sam $
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* \author Sam Hocevar <sam@zoy.org>
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* This file contains simple mathematical routines.
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#include "caca_internals.h"
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* \brief Generate a random integer within a range.
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* \param min The lower bound of the integer range.
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* \param max The upper bound of the integer range.
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* \return A random integer comprised between \p min and \p max, inclusive.
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int caca_rand(int min, int max)
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return min + (int)((1.0*(max-min+1)) * rand() / (RAND_MAX+1.0));
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* \brief Approximate a square root, using Newton's method to avoid
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* costly floating point calculations.
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* \param a A positive integer.
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* \return The approximate square root of \p a.
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unsigned int caca_sqrt(unsigned int a)
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unsigned int x = a < 10 ? 1
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/* Newton's method. Three iterations would be more than enough. */
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x = (x * x + a) / x / 2;
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x = (x * x + a) / x / 2;
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x = (x * x + a) / x / 2;
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x = (x * x + a) / x / 2;
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return 2 * caca_sqrt(a / 4);