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- #ifndef __INC_LIB8TION_RANDOM_H
- #define __INC_LIB8TION_RANDOM_H
- ///@ingroup lib8tion
-
- ///@defgroup Random Fast random number generators
- /// Fast 8- and 16- bit unsigned random numbers.
- /// Significantly faster than Arduino random(), but
- /// also somewhat less random. You can add entropy.
- ///@{
-
- // X(n+1) = (2053 * X(n)) + 13849)
- #define FASTLED_RAND16_2053 ((uint16_t)(2053))
- #define FASTLED_RAND16_13849 ((uint16_t)(13849))
-
- /// random number seed
- extern uint16_t rand16seed;// = RAND16_SEED;
-
- /// Generate an 8-bit random number
- LIB8STATIC uint8_t random8(void)
- {
- rand16seed = (rand16seed * FASTLED_RAND16_2053) + FASTLED_RAND16_13849;
- // return the sum of the high and low bytes, for better
- // mixing and non-sequential correlation
- return (uint8_t)(((uint8_t)(rand16seed & 0xFF)) +
- ((uint8_t)(rand16seed >> 8)));
- }
-
- /// Generate a 16 bit random number
- LIB8STATIC uint16_t random16(void)
- {
- rand16seed = (rand16seed * FASTLED_RAND16_2053) + FASTLED_RAND16_13849;
- return rand16seed;
- }
-
- /// Generate an 8-bit random number between 0 and lim
- /// @param lim the upper bound for the result
- LIB8STATIC uint8_t random8_max(uint8_t lim)
- {
- uint8_t r = random8();
- r = (r*lim) >> 8;
- return r;
- }
-
- /// Generate an 8-bit random number in the given range
- /// @param min the lower bound for the random number
- /// @param lim the upper bound for the random number
- LIB8STATIC uint8_t random8_min_max(uint8_t min, uint8_t lim)
- {
- uint8_t delta = lim - min;
- uint8_t r = random8_max(delta) + min;
- return r;
- }
-
- /// Generate an 16-bit random number between 0 and lim
- /// @param lim the upper bound for the result
- LIB8STATIC uint16_t random16_max(uint16_t lim)
- {
- uint16_t r = random16();
- uint32_t p = (uint32_t)lim * (uint32_t)r;
- r = p >> 16;
- return r;
- }
-
- /// Generate an 16-bit random number in the given range
- /// @param min the lower bound for the random number
- /// @param lim the upper bound for the random number
- LIB8STATIC uint16_t random16_min_max( uint16_t min, uint16_t lim)
- {
- uint16_t delta = lim - min;
- uint16_t r = random16_max(delta) + min;
- return r;
- }
-
- /// Set the 16-bit seed used for the random number generator
- LIB8STATIC void random16_set_seed(uint16_t seed)
- {
- rand16seed = seed;
- }
-
- /// Get the current seed value for the random number generator
- LIB8STATIC uint16_t random16_get_seed(void)
- {
- return rand16seed;
- }
-
- /// Add entropy into the random number generator
- LIB8STATIC void random16_add_entropy(uint16_t entropy)
- {
- rand16seed += entropy;
- }
-
- ///@}
-
- #endif
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