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- #ifndef STK_NOISE_H
- #define STK_NOISE_H
-
- #include "Generator.h"
- #include <stdlib.h>
-
- namespace stk {
-
- /***************************************************/
- /*! \class Noise
- \brief STK noise generator.
-
- Generic random number generation using the
- C rand() function. The quality of the rand()
- function varies from one OS to another.
-
- by Perry R. Cook and Gary P. Scavone, 1995--2017.
- */
- /***************************************************/
-
- class Noise : public Generator
- {
- public:
-
- //! Default constructor that can also take a specific seed value.
- /*!
- If the seed value is zero (the default value), the random number generator is
- seeded with the system time.
- */
- Noise( unsigned int seed = 0 );
-
- //! Seed the random number generator with a specific seed value.
- /*!
- If no seed is provided or the seed value is zero, the random
- number generator is seeded with the current system time.
- */
- void setSeed( unsigned int seed = 0 );
-
- //! Return the last computed output value.
- StkFloat lastOut( void ) const { return lastFrame_[0]; };
-
- //! Compute and return one output sample.
- StkFloat tick( void );
-
- //! Fill a channel of the StkFrames object with computed outputs.
- /*!
- The \c channel argument must be less than the number of
- channels in the StkFrames argument (the first channel is specified
- by 0). However, range checking is only performed if _STK_DEBUG_
- is defined during compilation, in which case an out-of-range value
- will trigger an StkError exception.
- */
- StkFrames& tick( StkFrames& frames, unsigned int channel = 0 );
-
- protected:
-
- };
-
- inline StkFloat Noise :: tick( void )
- {
- return lastFrame_[0] = (StkFloat) ( 2.0 * rand() / (RAND_MAX + 1.0) - 1.0 );
- }
-
- inline StkFrames& Noise :: tick( StkFrames& frames, unsigned int channel )
- {
- #if defined(_STK_DEBUG_)
- if ( channel >= frames.channels() ) {
- oStream_ << "Noise::tick(): channel and StkFrames arguments are incompatible!";
- handleError( StkError::FUNCTION_ARGUMENT );
- }
- #endif
-
- StkFloat *samples = &frames[channel];
- unsigned int hop = frames.channels();
- for ( unsigned int i=0; i<frames.frames(); i++, samples += hop )
- *samples = (StkFloat) ( 2.0 * rand() / (RAND_MAX + 1.0) - 1.0 );
-
- lastFrame_[0] = *(samples-hop);
- return frames;
- }
-
- } // stk namespace
-
- #endif
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