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58829022ed
Greatly reduces error rate (half, or 0 zero errors, depends on in/out ranges) for round-trip mapping at the same performance.
87 lines
2.3 KiB
C++
87 lines
2.3 KiB
C++
/* -*- mode: jde; c-basic-offset: 2; indent-tabs-mode: nil -*- */
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/*
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Part of the Wiring project - http://wiring.org.co
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Copyright (c) 2004-06 Hernando Barragan
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Modified 13 August 2006, David A. Mellis for Arduino - http://www.arduino.cc/
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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 2.1 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
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Public License along with this library; if not, write to the
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Free Software Foundation, Inc., 59 Temple Place, Suite 330,
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Boston, MA 02111-1307 USA
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$Id$
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*/
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extern "C" {
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#include <stdlib.h>
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}
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#include "esp8266_peri.h"
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static bool s_randomSeedCalled = false;
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void randomSeed(unsigned long seed) {
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if(seed != 0) {
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srand(seed);
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s_randomSeedCalled = true;
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}
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}
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long random(long howbig) {
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if(howbig == 0) {
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return 0;
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}
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// if randomSeed was called, fall back to software PRNG
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uint32_t val = (s_randomSeedCalled) ? rand() : RANDOM_REG32;
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return val % howbig;
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}
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long random(long howsmall, long howbig) {
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if(howsmall >= howbig) {
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return howsmall;
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}
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long diff = howbig - howsmall;
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return random(diff) + howsmall;
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}
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long secureRandom(long howbig) {
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if(howbig == 0) {
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return 0;
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}
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return RANDOM_REG32 % howbig;
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}
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long secureRandom(long howsmall, long howbig) {
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if(howsmall >= howbig) {
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return howsmall;
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}
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long diff = howbig - howsmall;
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return secureRandom(diff) + howsmall;
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}
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long map(long x, long in_min, long in_max, long out_min, long out_max) {
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const long dividend = out_max - out_min;
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const long divisor = in_max - in_min;
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const long delta = x - in_min;
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return (delta * dividend + (divisor / 2)) / divisor + out_min;
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}
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unsigned int makeWord(unsigned int w) {
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return w;
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}
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unsigned int makeWord(unsigned char h, unsigned char l) {
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return (h << 8) | l;
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}
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