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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, 2004 by Benno Senoner and Christian Schoenebeck * |
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* Copyright (C) 2005 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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#include "EGADSR.h" |
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|
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namespace LinuxSampler { namespace gig { |
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|
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EGADSR::EGADSR() { |
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enterEndStage(); |
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Level = 0.0; |
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CalculateFadeOutCoeff(CONFIG_EG_MIN_RELEASE_TIME, 44100.0); // even if the sample rate will be 192kHz it won't hurt at all |
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} |
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|
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void EGADSR::CalculateFadeOutCoeff(float FadeOutTime, float SampleRate) { |
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const float killSteps = FadeOutTime * SampleRate; |
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FadeOutCoeff = -1.0f / killSteps; |
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} |
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|
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void EGADSR::update(event_t Event, double SamplePos, float CurrentPitch, uint SampleRate) { |
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switch (Stage) { |
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case stage_attack: |
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if (StepsLeft) { |
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PostponedEvent = Event; |
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} else { |
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if (Event == event_release) |
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enterReleasePart1Stage(); |
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else if (Event == event_cancel_release) |
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enterSustainStage(); |
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else if (PostponedEvent == event_release) |
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enterReleasePart1Stage(); |
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else if (PostponedEvent == event_cancel_release) |
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enterSustainStage(); |
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else if (HoldAttack) |
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enterAttackHoldStage(SamplePos, CurrentPitch); |
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else |
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enterDecay1Part1Stage(SampleRate); |
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} |
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break; |
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case stage_attack_hold: |
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switch (Event) { |
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case event_stage_end: |
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enterDecay1Part1Stage(SampleRate); |
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break; |
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case event_release: |
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enterReleasePart1Stage(); |
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break; |
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case event_cancel_release: |
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if (InfiniteSustain) |
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enterSustainStage(); |
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else |
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enterDecay1Part1Stage(SampleRate); |
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break; |
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} |
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break; |
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case stage_decay1_part1: |
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switch (Event) { |
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case stage_end: |
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enterDecay1Part2Stage(); |
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break; |
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case event_release: |
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enterReleasePart1Stage(); |
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break; |
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case event_cancel_release: |
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if (InfiniteSustain) |
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enterSustainStage(); |
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else |
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enterDecay2Stage(SampleRate); |
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break; |
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} |
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break; |
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case stage_decay1_part2: |
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switch (Event) { |
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case event_release: |
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enterReleasePart1Stage(); |
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break; |
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case event_stage_end: // fall through |
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case event_cancel_release: |
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if (InfiniteSustain) |
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enterSustainStage(); |
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else |
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enterDecay2Stage(SampleRate); |
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break; |
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} |
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break; |
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case stage_decay2: |
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switch (Event) { |
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case event_stage_end: |
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enterFadeOutStage(); |
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break; |
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case event_release: |
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enterReleasePart1Stage(); |
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break; |
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} |
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break; |
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case stage_sustain: |
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switch (Event) { |
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case event_stage_end: {// just refresh time |
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const int intMax = (unsigned int) -1 >> 1; |
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StepsLeft = intMax; // we use the highest possible value |
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break; |
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} |
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case event_release: |
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enterReleasePart1Stage(); |
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break; |
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} |
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break; |
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case stage_release_part1: |
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switch (Event) { |
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case event_stage_end: |
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enterReleasePart2Stage(); |
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break; |
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case event_cancel_release: |
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if (InfiniteSustain) |
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enterSustainStage(); |
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else |
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enterDecay2Stage(SampleRate); |
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break; |
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} |
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break; |
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case stage_release_part2: |
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switch (Event) { |
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case event_stage_end: |
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enterFadeOutStage(); |
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break; |
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case event_cancel_release: |
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if (InfiniteSustain) |
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enterSustainStage(); |
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else |
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enterDecay2Stage(SampleRate); |
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break; |
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} |
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break; |
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case stage_fadeout: |
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switch (Event) { |
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case event_stage_end: |
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enterEndStage(); |
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break; |
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} |
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break; |
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} |
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} |
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|
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void EGADSR::trigger(uint PreAttack, float AttackTime, bool HoldAttack, long LoopStart, float Decay1Time, double Decay2Time, bool InfiniteSustain, uint SustainLevel, float ReleaseTime, float Volume, uint SampleRate) { |
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|
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enterAttackStage(PreAttack, AttackTime, SampleRate, 0.0, 1.0f); |
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|
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if (SustainLevel) { |
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this->SustainLevel = SustainLevel / 1000.0; |
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} else { |
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// sustain level 0 means that voice dies after decay 1 |
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this->SustainLevel = CONFIG_EG_BOTTOM; |
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InfiniteSustain = false; |
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Decay2Time = CONFIG_EG_MIN_RELEASE_TIME; |
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} |
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this->InfiniteSustain = InfiniteSustain; |
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this->HoldAttack = HoldAttack; |
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this->LoopStart = LoopStart; |
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|
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this->Decay1Time = Decay1Time; |
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this->Decay2Time = Decay2Time; |
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|
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invVolume = 1 / Volume; |
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ExpOffset = (0.25 - 1 / 3.55) * invVolume; |
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|
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// calculate release stage parameters (lin+exp curve) |
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if (ReleaseTime < CONFIG_EG_MIN_RELEASE_TIME) ReleaseTime = CONFIG_EG_MIN_RELEASE_TIME; // to avoid click sounds at the end of the sample playback |
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const float ReleaseStepsLeft = (long) (ReleaseTime * SampleRate); |
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ReleaseSlope = 1.365 * (0 - 1) / ReleaseStepsLeft; |
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ReleaseCoeff = ReleaseSlope * invVolume; |
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ReleaseSlope *= 3.55; |
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ReleaseCoeff2 = exp(ReleaseSlope); |
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ReleaseCoeff3 = ExpOffset * (1 - ReleaseCoeff2); |
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ReleaseLevel2 = 0.25 * invVolume; |
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} |
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|
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void EGADSR::enterAttackStage(const uint PreAttack, const float AttackTime, const uint SampleRate, const double SamplePos, const float CurrentPitch) { |
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Stage = stage_attack; |
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Segment = segment_lin; |
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// Measurements of GSt output shows that the real attack time |
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// is about 65.5% of the value specified in the gig file. |
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StepsLeft = (int) (0.655f * AttackTime * SampleRate); |
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if (StepsLeft) { |
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Level = (float) PreAttack / 1000.0; |
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Coeff = 0.896f * (1.0f - Level) / StepsLeft; // max level is a bit lower if attack != 0 |
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} else { // immediately jump to the next stage |
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if (HoldAttack) enterAttackHoldStage(SamplePos, CurrentPitch); |
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else enterDecay1Part1Stage(SampleRate); |
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} |
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PostponedEvent = (event_t) -1; // init with anything except release or cancel_release |
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} |
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|
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void EGADSR::enterAttackHoldStage(const double SamplePos, const float CurrentPitch) { |
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Stage = stage_attack_hold; |
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Segment = segment_lin; |
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Coeff = 0.0f; // don't rise anymore |
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StepsLeft = (int) (LoopStart - SamplePos / CurrentPitch); // FIXME: just an approximation, inaccuracy grows with higher audio fragment size, sufficient for usual fragment sizes though |
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} |
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|
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void EGADSR::enterDecay1Part1Stage(const uint SampleRate) { |
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// The decay1 and release stage both consist of two parts, |
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// first a linear curve, f, followed by an exponential curve, |
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// g: |
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// |
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// f(x + d) = f(x) + Coeff |
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// g(x + d) = Coeff2 * g(x) + Coeff3 |
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// |
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// (where d is 1/SampleRate). The transition from f to g is |
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// done when f(x) has reached Level2 = 25% of full volume. |
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StepsLeft = (int) (Decay1Time * SampleRate); |
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if (StepsLeft && SustainLevel < 1.0) { |
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Stage = stage_decay1_part1; |
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Segment = segment_lin; |
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Decay1Slope = 1.365 * (SustainLevel - 1.0) / StepsLeft; |
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Coeff = Decay1Slope * invVolume; |
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Decay1Level2 = 0.25 * invVolume; |
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StepsLeft = int((RTMath::Max(Decay1Level2, SustainLevel) - Level) / Coeff); |
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} else { |
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Level = SustainLevel; |
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if (InfiniteSustain) enterSustainStage(); |
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else enterDecay2Stage(SampleRate); |
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} |
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} |
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|
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void EGADSR::enterDecay1Part2Stage() { |
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Stage = stage_decay1_part2; |
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Segment = segment_exp; |
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Decay1Slope *= 3.55; |
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Coeff = exp(Decay1Slope); |
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Offset = ExpOffset * (1 - Coeff); |
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Level = Decay1Level2; |
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StepsLeft = int(log((SustainLevel - ExpOffset) / (Level - ExpOffset)) / Decay1Slope); |
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} |
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|
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void EGADSR::enterDecay2Stage(const uint SampleRate) { |
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Stage = stage_decay2; |
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Segment = segment_lin; |
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Decay2Time = RTMath::Max(Decay2Time, CONFIG_EG_MIN_RELEASE_TIME); |
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StepsLeft = (int) (Decay2Time * SampleRate); |
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Coeff = (-1.03 / StepsLeft) * invVolume; |
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//FIXME: do we really have to calculate 'StepsLeft' two times? |
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StepsLeft = int((CONFIG_EG_BOTTOM - Level) / Coeff); |
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} |
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|
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void EGADSR::enterSustainStage() { |
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Stage = stage_sustain; |
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Segment = segment_lin; |
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Coeff = 0.0f; // don't change the envelope level in this stage |
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const int intMax = (unsigned int) -1 >> 1; |
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StepsLeft = intMax; // we use the highest value possible (we refresh StepsLeft in update() in case) |
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} |
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|
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void EGADSR::enterReleasePart1Stage() { |
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Stage = stage_release_part1; |
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Segment = segment_lin; |
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StepsLeft = int((ReleaseLevel2 - Level) / ReleaseCoeff); |
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Coeff = ReleaseCoeff; |
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} |
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|
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void EGADSR::enterReleasePart2Stage() { |
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Stage = stage_release_part2; |
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Segment = segment_exp; |
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StepsLeft = int(log((CONFIG_EG_BOTTOM - ExpOffset) / (Level - ExpOffset)) / ReleaseSlope); |
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Coeff = ReleaseCoeff2; |
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Offset = ReleaseCoeff3; |
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} |
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|
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void EGADSR::enterFadeOutStage() { |
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Stage = stage_fadeout; |
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Segment = segment_lin; |
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StepsLeft = int(Level / (-FadeOutCoeff)); |
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Coeff = FadeOutCoeff; |
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} |
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|
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void EGADSR::enterEndStage() { |
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Stage = stage_end; |
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Segment = segment_end; |
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} |
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|
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}} // namespace LinuxSampler::gig |