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/*************************************************************************** |
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* * |
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* LinuxSampler - modular, streaming capable sampler * |
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* * |
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* Copyright (C) 2011 Grigor Iliev * |
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* * |
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* This program is free software; you can redistribute it and/or modify * |
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* it under the terms of the GNU General Public License as published by * |
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* the Free Software Foundation; either version 2 of the License, or * |
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* (at your option) any later version. * |
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* * |
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* This program 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 * |
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* GNU General Public License for more details. * |
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* * |
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* You should have received a copy of the GNU General Public License * |
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* along with this program; if not, write to the Free Software * |
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, * |
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* MA 02111-1307 USA * |
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***************************************************************************/ |
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|
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#ifndef __LS_SIGNALUNIT_H__ |
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#define __LS_SIGNALUNIT_H__ |
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|
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#include "../../common/ArrayList.h" |
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|
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|
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namespace LinuxSampler { |
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|
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class SignalUnitRack; |
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|
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/** |
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* A signal unit consist of internal signal generator (like envelope generator, |
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* low frequency oscillator, etc) with a number of generator parameters which |
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* influence/modulate/dynamically change the generator's signal in some manner. |
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* Each generator parameter (also called signal unit parameter) can receive |
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* signal from another signal unit and use this signal to dynamically change the |
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* behavior of the signal generator. In turn, the signal of this unit can be fed |
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* to another unit(s) and influence its parameters. |
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*/ |
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class SignalUnit { |
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public: |
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|
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/** |
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* This class represents a parameter which will influence the signal |
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* unit to which it belongs in certain way. |
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* For example, let's say the signal unit is a low frequency oscillator |
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* with frequency 1Hz. If we want to modulate the LFO to start with 1Hz |
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* and increment its frequency to 5Hz in 1 second, we can add |
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* a parameter which signal source is an envelope |
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* generator with attack time of 1 second and coefficient 4. Thus, the |
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* normalized level of the EG will move from 0 to 1 in one second. |
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* On every time step (sample point) the normalized level |
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* will be multiplied by 4 (the parameter coefficient) and added to the |
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* LFO's frequency. |
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* So, after 1 second, the LFO frequency will be 1x4 + 1 = 5Hz. |
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* We can also add another parameter for modulating the LFO's pitch depth |
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* and so on. |
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*/ |
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class Parameter { |
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public: |
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SignalUnit* pUnit; /* The source unit whose output signal |
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* will modulate the parameter. |
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*/ |
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|
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float Coeff; // The modulation coefficient |
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|
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|
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Parameter() : Coeff(1), pUnit(NULL) { } |
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|
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/** |
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* @param unit The source unit used to influence this parameter. |
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* @param coeff The coefficient by which the normalized signal |
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* received from the source unit should be multiplied when a |
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* default transformation is done. |
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*/ |
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Parameter(SignalUnit* unit, float coeff = 1) { |
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pUnit = unit; |
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Coeff = coeff; |
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} |
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|
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Parameter(const Parameter& Prm) { Copy(Prm); } |
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void operator=(const Parameter& Prm) { Copy(Prm); } |
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|
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void Copy(const Parameter& Prm) { |
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if (this == &Prm) return; |
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|
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pUnit = Prm.pUnit; |
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Coeff = Prm.Coeff; |
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} |
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|
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|
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/** |
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* Calculates the transformation for this parameter |
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* which should be applied to the parameter's value |
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* and multiplies by Coeff. |
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* This implementation of the method just multiplies by Coeff. |
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*/ |
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virtual float Transform(float val) { |
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return val * Coeff; |
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} |
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|
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/** |
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* Gets the current value of the parameter. |
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* This implementation returns the current signal level of the |
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* source unit with applied transformation if the source unit is |
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* active, otherwise returns 1. |
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* Note that this method assume that pUnit is not NULL. |
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*/ |
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virtual float GetValue() { |
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return pUnit->Active() ? Transform(pUnit->GetLevel()) : 1.0f; |
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} |
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}; |
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|
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|
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public: |
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ArrayList<SignalUnit::Parameter> Params; // The list of parameters which are modulating the signal unit |
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|
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SignalUnit(SignalUnitRack* rack): pRack(rack), bActive(false), Level(0.0f), bCalculating(false), uiDelayTrigger(0) { } |
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SignalUnit(const SignalUnit& Unit): pRack(Unit.pRack) { Copy(Unit); } |
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void operator=(const SignalUnit& Unit) { Copy(Unit); } |
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|
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void Copy(const SignalUnit& Unit) { |
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if (this == &Unit) return; |
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|
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bActive = Unit.bActive; |
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Level = Unit.Level; |
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Params = Unit.Params; |
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uiDelayTrigger = Unit.uiDelayTrigger; |
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bCalculating = false; |
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} |
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|
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/* |
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* Determines whether the unit is active. |
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* If the unit is not active, its level should be ignored. |
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* For endpoint unit this method determines whether |
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* the rendering should be stopped. |
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*/ |
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virtual bool Active() { return bActive; } |
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|
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/** |
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* Override this method to process the current control change events. |
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* @param itEvent - iterator pointing to the event to be processed. |
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*/ |
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virtual void ProcessCCEvent(uint8_t Controller, uint8_t Value) { } |
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|
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virtual void EnterReleaseStage() { } |
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|
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virtual void CancelRelease() { } |
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|
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/** |
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* Gets the normalized level of the unit for the current |
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* time step (sample point). The level is calculated if it's not |
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* calculated for the current step yet. Because the level depends on |
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* the parameters, their levels are calculated too. |
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*/ |
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virtual float GetLevel() { |
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if (!bRecalculate) return Level; |
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|
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if (bCalculating) { |
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std::cerr << "SignalUnit: Loop detected. Aborted!"; |
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return Level; |
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} |
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|
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bCalculating = true; |
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|
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for(int i = 0; i < Params.size(); i++) { |
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Params[i].GetValue(); |
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} |
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bRecalculate = bCalculating = false; |
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return Level; |
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} |
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|
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/** |
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* Will be called to increment the time with one sample point. |
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* The unit should recalculate or prepare for recalculation |
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* its current level on every call of this function. |
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* Note that it is not known whether all source signal unit's levels |
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* are recalculated before the call of this method. So, the calculations |
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* that depends on the unit's parameters should be postponed to |
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* the call of GetLevel(). |
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*/ |
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virtual void Increment() { bRecalculate = true; } |
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|
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/** |
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* Initializes and triggers the unit. |
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* Note that when a voice is the owner of a unit rack, all settings |
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* should be reset when this method is called, because the sampler |
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* is reusing the voice objects. |
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*/ |
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virtual void Trigger() = 0; |
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|
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/** |
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* When the signal unit rack is triggered, it triggers all signal |
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* units it holds. If for some reason the triggering of a unit |
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* should be delayed, this method can be set to return non-zero value |
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* specifying the delay in time steps. |
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* Note that this is only a helper method and the implementation |
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* should be done manually. |
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*/ |
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virtual uint DelayTrigger() { return uiDelayTrigger; } |
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|
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/** |
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* A helper method which checks whether the delay |
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* stage is finished. |
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*/ |
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bool DelayStage(); |
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|
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protected: |
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SignalUnitRack* const pRack; |
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|
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bool bActive; /* Don't use it to check the active state of the unit!!! |
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* Use Active() instead! */ |
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float Level; |
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bool bRecalculate; /* Determines whether the unit's level should be recalculated. */ |
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bool bCalculating; /* Determines whether the unit is in process of calculating |
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* its level. Used for preventing infinite loops. |
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*/ |
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|
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uint uiDelayTrigger; /* in time steps */ |
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|
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}; |
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class EndpointSignalUnit: public SignalUnit { |
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public: |
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EndpointSignalUnit(SignalUnitRack* rack): SignalUnit(rack) { } |
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|
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/** |
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* Gets the volume modulation value |
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* for the current time step (sample point). |
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*/ |
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virtual float GetVolume() = 0; |
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|
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/** |
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* Gets the filter cutoff frequency modulation value |
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* for the current time step (sample point). |
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*/ |
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virtual float GetFilterCutoff() = 0; |
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|
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/** |
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* Gets the pitch modulation value |
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* for the current time step (sample point). |
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*/ |
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virtual float GetPitch() = 0; |
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/** |
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* Gets the resonance modulation value |
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* for the current time step (sample point). |
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*/ |
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virtual float GetResonance() = 0; |
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|
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/** Should return value in the range [-100, 100] (L <-> R) */ |
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virtual float GetPan() = 0; |
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|
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virtual float CalculateFilterCutoff(float cutoff) { |
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cutoff *= GetFilterCutoff(); |
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return cutoff > 13500 ? 13500 : cutoff; |
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} |
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virtual float CalculatePitch(float pitch) { |
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return GetPitch() * pitch; |
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} |
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virtual float CalculateResonance(float res) { |
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return GetResonance() * res; |
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} |
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/** Should return value in the range [0, 127] (L <-> R) */ |
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virtual uint8_t CaluclatePan(uint8_t pan) { |
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int p = pan + GetPan() * 0.63; |
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if (p < 0) return 0; |
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if (p > 127) return 127; |
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return p; |
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} |
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}; |
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|
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/** |
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* Continuous controller signal unit. |
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* The level of this unit corresponds to the controller changes |
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* and is normalized to be in the range from -1 to +1. |
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*/ |
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class CCSignalUnit: public SignalUnit { |
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private: |
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uint8_t Ctrl; // The number of the MIDI controller which modulates this signal unit. |
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|
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public: |
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CCSignalUnit(SignalUnitRack* rack, uint8_t Controller): SignalUnit(rack) { |
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Ctrl = Controller; |
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} |
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CCSignalUnit(const CCSignalUnit& Unit): SignalUnit(Unit.pRack) { Copy(Unit); } |
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void operator=(const CCSignalUnit& Unit) { Copy(Unit); } |
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|
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void Copy(const CCSignalUnit& Unit) { |
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Ctrl = Unit.Ctrl; |
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SignalUnit::Copy(Unit); |
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} |
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|
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virtual void Increment() { } |
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virtual void ProcessCCEvent(uint8_t Controller, uint8_t Value) { |
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if (Controller != Ctrl) return; |
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|
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// Normalize the value so it belongs to the interval [-1, +1] |
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Level = 2 * Value; |
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Level = Level/127.0f - 1.0f; |
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|
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if (!bActive) bActive = true; |
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} |
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}; |
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|
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} // namespace LinuxSampler |
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#endif /* __LS_SIGNALUNIT_H__ */ |