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/*************************************************************************** |
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* * |
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* Copyright (C) 2005 - 2019 Christian Schoenebeck * |
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* * |
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* This library 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 library 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 library; 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_LFOBASE_H__ |
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#define __LS_LFOBASE_H__ |
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|
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#include "../LFO.h" |
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#include "../../common/RTMath.h" |
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|
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#include <math.h> |
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#include <stdint.h> |
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|
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namespace LinuxSampler { |
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|
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/** @brief POD base for all LFO implementations. |
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* |
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* This structure acts as POD (Plain Old Data structure) base for all LFO |
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* implementations. For efficiency reasons all our LFOs are C++ template |
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* classes. By deriving all those LFO C++ templase classes from this |
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* POD structure, it allows us to at least do a unified @code delete for |
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* any LFO object, which would not work on @code void* pointers (correctly). |
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* |
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* ATM this is actually only used in LFO.cpp. |
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*/ |
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struct LFOPOD { |
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}; |
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|
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/** @brief LFO (abstract base class) |
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* |
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* Abstract base class for all Low Frequency Oscillator implementations. |
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*/ |
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template<LFO::range_type_t RANGE> |
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class LFOBase : public LFOPOD { |
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public: |
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|
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// *************** attributes *************** |
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// * |
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|
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uint8_t ExtController; ///< MIDI control change controller number if the LFO is controlled by an external controller, 0 otherwise. |
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|
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|
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// *************** methods *************** |
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// * |
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|
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/** |
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* Constructor |
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* |
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* @param Max - maximum value of the output levels |
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*/ |
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LFOBase(float Max) { |
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this->ExtController = 0; |
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this->Max = Max; |
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this->InternalDepth = 0; |
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this->Frequency = 20.f; |
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this->ExtControlValue = 0; |
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this->ExtControlDepthCoeff = 0; |
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this->ScriptDepthFactor = 1.f; |
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this->ScriptFrequencyFactor = 1.f; |
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this->pFinalDepth = NULL; |
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this->pFinalFrequency = NULL; |
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} |
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|
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virtual ~LFOBase() { |
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} |
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|
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/** |
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* Calculates exactly one sample point of the LFO wave. This |
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* inline method has to be implemented by the descendant. |
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* |
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* @returns next LFO level |
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*/ |
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//abstract inline float render(); //< what a pity that abstract inliners are not supported by C++98 (probably by upcoming C++0x?) |
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|
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/** |
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* Update LFO depth with a new external controller value. This |
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* inline method has to be implemented by the descendant. |
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* |
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* @param ExtControlValue - new external controller value |
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*/ |
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//abstract inline void updateByMIDICtrlValue(const uint16_t& ExtControlValue); //< what a pity that abstract inliners are not supported by C++98 (probably by upcoming C++0x?) |
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|
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/** |
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* Will be called by the voice when the key / voice was triggered. |
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* |
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* @param Frequency - frequency of the oscillator in Hz |
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* @param StartLevel - on which level the wave should start |
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* @param InternalDepth - firm, internal oscillator amplitude |
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* @param ExtControlDepth - defines how strong the external MIDI |
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* controller has influence on the |
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* oscillator amplitude |
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* @param FlipPhase - inverts the oscillator wave against |
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* a horizontal axis |
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* @param SampleRate - current sample rate of the engines |
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* audio output signal |
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*/ |
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virtual void trigger(float Frequency, LFO::start_level_t StartLevel, uint16_t InternalDepth, uint16_t ExtControlDepth, bool FlipPhase, unsigned int SampleRate) = 0; |
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|
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protected: |
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float Max; |
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float InternalDepth; |
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float Frequency; ///< Internal base frequency for this LFO. |
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float ExtControlValue; ///< The current external MIDI controller value (0-127). |
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float ExtControlDepthCoeff; ///< A usually constant factor used to convert a new MIDI controller value from range 0-127 to the required internal implementation dependent value range. |
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float ScriptDepthFactor; ///< Usually neutral (1.0), only altered by external RT instrument script functions. |
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float ScriptFrequencyFactor; ///< Usually neutral (1.0), only altered by external RT instrument script functions. |
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float* pFinalDepth; ///< Usually NULL; it may be set to one of above's member variables in order to process that and ignore all other sources for LFO depth. |
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float* pFinalFrequency; ///< Usually NULL; it may be set to one of above's member variables in order to process that and ignore all other sources for LFO frequency. |
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}; |
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|
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} // namespace LinuxSampler |
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|
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#endif // __LS_LFOBASE_H__ |