| @@ -0,0 +1,66 @@ | |||
| /* | |||
| Part of the Wiring project - http://wiring.org.co | |||
| Copyright (c) 2004-06 Hernando Barragan | |||
| Modified 13 August 2006, David A. Mellis for Arduino - http://www.arduino.cc/ | |||
| This library is free software; you can redistribute it and/or | |||
| modify it under the terms of the GNU Lesser General Public | |||
| License as published by the Free Software Foundation; either | |||
| version 2.1 of the License, or (at your option) any later version. | |||
| This library 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 | |||
| Lesser General Public License for more details. | |||
| You should have received a copy of the GNU Lesser General | |||
| Public License along with this library; if not, write to the | |||
| Free Software Foundation, Inc., 59 Temple Place, Suite 330, | |||
| Boston, MA 02111-1307 USA | |||
| */ | |||
| #include <stdint.h> | |||
| static uint32_t seed; | |||
| void randomSeed(uint32_t newseed) | |||
| { | |||
| if (newseed > 0) seed = newseed; | |||
| } | |||
| void srandom(unsigned int newseed) | |||
| { | |||
| seed = newseed; | |||
| } | |||
| int32_t random(void) | |||
| { | |||
| int32_t hi, lo, x; | |||
| // the algorithm used in avr-libc 1.6.4 | |||
| x = seed; | |||
| if (x == 0) x = 123459876; | |||
| hi = x / 127773; | |||
| lo = x % 127773; | |||
| x = 16807 * lo - 2836 * hi; | |||
| if (x < 0) x += 0x7FFFFFFF; | |||
| seed = x; | |||
| return x; | |||
| } | |||
| uint32_t random(uint32_t howbig) | |||
| { | |||
| if (howbig == 0) return 0; | |||
| return random() % howbig; | |||
| } | |||
| int32_t random(int32_t howsmall, int32_t howbig) | |||
| { | |||
| if (howsmall >= howbig) return howsmall; | |||
| int32_t diff = howbig - howsmall; | |||
| return random(diff) + howsmall; | |||
| } | |||
| unsigned int makeWord(unsigned int w) { return w; } | |||
| unsigned int makeWord(unsigned char h, unsigned char l) { return (h << 8) | l; } | |||