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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) 2003 by Benno Senoner and Christian Schoenebeck * |
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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 __LFO_H__ |
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#define __LFO_H__ |
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|
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#include "global.h" |
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#include "rtelmemorypool.h" |
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#include "modulationsystem.h" |
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#include "gig.h" |
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|
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/** |
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* Low Frequency Oscillator |
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* |
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* Synthesizes a triangular wave for modulating arbitrary synthesis |
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* parameters. |
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*/ |
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class LFO { |
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public: |
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/** |
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* Defines how the LFO applies it's values to the synthesis |
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* parameter matrix. |
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*/ |
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enum manipulation_type_t { |
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manipulation_type_add, ///< Add LFO's values to the synthesis paramter matrix. |
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manipulation_type_multiply ///< Multiply LFO's values with the ones from the synthesis parameter matrix. |
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}; |
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/** |
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* Defines the position of the LFO wave within the given value range |
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* and from which value to start when the LFO is triggered. |
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*/ |
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enum propagation_t { |
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propagation_top_down, ///< Wave level starts from given max. and grows down with growing oscillator depth. |
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propagation_middle_balanced, ///< Wave level starts from the middle of the given value range and grows in both directions with growing oscillator depth. |
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propagation_bottom_up ///< Wave level starts from given min. and grows up with growing oscillator depth. |
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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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LFO(ModulationSystem::destination_t ModulationDestination, manipulation_type_t ManipulationType, float Min, float Max, propagation_t Propagation, RTELMemoryPool<ModulationSystem::Event>* pEventPool); |
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void Process(uint Samples); |
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void Trigger(float Frequency, uint16_t InternalDepth, uint16_t ExtControlDepth, uint16_t ExtControlValue, bool FlipPhase, uint Delay); |
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void Reset(); |
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/** |
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* Will be called by the voice to inform the LFO about a change of |
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* the external controller's value. |
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* |
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* @param pEvent - control change event of external controller |
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*/ |
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inline void SendEvent(ModulationSystem::Event* pEvent) { |
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if (ExtController && pEvent->FragmentPos() >= this->TriggerDelay) pEvents->alloc_assign(*pEvent); |
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} |
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~LFO(); |
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protected: |
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RTEList<ModulationSystem::Event>* pEvents; |
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ModulationSystem::destination_t ModulationDestination; |
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manipulation_type_t ManipulationType; |
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propagation_t Propagation; |
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int TriggerDelay; |
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float Min; |
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float Max; |
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float CurrentMin; |
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float CurrentMax; |
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float FrequencyCoeff; |
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float ExtControlDepthCoeff; |
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float InternalDepth; |
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float Range; |
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float Coeff; |
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float Level; |
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|
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inline void RecalculateCoeff(uint16_t ExtControlValue) { |
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float currentrange = InternalDepth + ExtControlValue * ExtControlDepthCoeff; |
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if (currentrange > Range) currentrange = Range; |
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Coeff = (Coeff < 0) ? -(currentrange * FrequencyCoeff) |
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: currentrange * FrequencyCoeff; |
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switch (Propagation) { |
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case propagation_top_down: { |
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CurrentMax = Max; |
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CurrentMin = Max - currentrange; |
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break; |
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} |
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case propagation_middle_balanced: { |
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float rangediff = (Range - currentrange) * 0.5f; |
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CurrentMax = Max - rangediff; |
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CurrentMin = Min + rangediff; |
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break; |
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} |
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case propagation_bottom_up: { |
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CurrentMax = Max - currentrange; |
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CurrentMin = Min; |
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break; |
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} |
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} |
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} |
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}; |
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|
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#endif // __LFO_H__ |