DSP/extensions/GeneratorLib/includes/TTRamp.h

/* 
 * TTBlue Ramp Generator
 * Copyright © 2008, Timothy Place
 * 
 * License: This code is licensed under the terms of the "New BSD License"
 * http://creativecommons.org/licenses/BSD/
 */

#ifndef __TT_RAMP_H__
#define __TT_RAMP_H__

#include "TTDSP.h"


/** TTRamp generates a linear traversal from 0.0 to 1.0 over the course of a specified time period.
    The first sample of the ramp is 0.0 and the last sample of the ramp is 1.0.
    This behaviour makes this ramp suitable for generating a window functions or similar where 
    all values of the function are to be present over the time encapsulated by the ramping signal.
 */ 
class TTRamp : TTAudioObjectBase {
    TTCLASS_SETUP(TTRamp)

protected:

    enum rampDirection {
        kUP = 0,
        kDOWN
    };
    
    TTSymbol            attrMode;               ///< mode: sample_accurate or vector_accurate
    TTFloat64           attrRampTime;           ///< ramp time in milliseconds
    TTUInt32            rampSamples;            ///< ramp time in samples
    TTFloat64           attrCurrentValue;       ///< 
    TTFloat64           attrDestinationValue;   ///< 
    TTFloat64           step;                   ///< 
    TTBoolean           direction;              ///< 0 = ramp up, 1 = ramp down

    /** Internal method for setting which process method to use. */
    void setupProcess();

    /** Internal method called when the ramp is triggered (by setting the rampTime) */
    void setStep();

    /** Process method -- This method is special!  It only sets the first sample of the vector and does not use it's input! */
    TTErr processVectorAccurateDown(TTAudioSignalArrayPtr inputs, TTAudioSignalArrayPtr outputs);
    /** Process method -- This method is special!  It only sets the first sample of the vector and does not use it's input! */
    TTErr processVectorAccurateUp(TTAudioSignalArrayPtr inputs, TTAudioSignalArrayPtr outputs);
    /** Process method  */
    TTErr processSampleAccurateDown(TTAudioSignalArrayPtr inputs, TTAudioSignalArrayPtr outputs);
    /** Process method  */
    TTErr processSampleAccurateUp(TTAudioSignalArrayPtr inputs, TTAudioSignalArrayPtr outputs);
    
    /** Setter for the mode attribute.  The options are 'sample' and 'vector' which determine 
     the desired accuracy of the ramp that is generated. */
    TTErr setMode(const TTValue& value);
    
    /** Trigger a ramp with a time set in samples */
    TTErr RampTimeInSamples(const TTValue& newValue);
    /** Trigger a ramp with a time set in milliseconds */
    TTErr setRampTime(const TTValue& newValue);
    
    /** Stop the current ramp.          */
    TTErr Stop();
    
    /** Unit Tests  */
    virtual TTErr test(TTValue& returnedTestInfo);  
    
};


#endif // __TT_RAMP_H__