我有一个大学作业，要求我使用 VST SDK 2.4 构建一个简单的加法合成器。
到目前为止，我已经将部分相加和一个信封。
我认为信封有效，但不确定，因为它根据推子/滑块位置拉动其值，而且他们似乎不想打球。
我确信这与我的值/范围缩放有关，因为延音滑块似乎工作。
我可能花了太长时间重新检查我的代码，但无法解决问题。
不确定哪些代码会有用，所以我刚刚附上了很多。
任何帮助是极大的赞赏。
提前致谢，
本。
ADSR.h
#ifndef __ADSR
#define __ADSR
#include <math.h>
class ADSR
{
public:
ADSR();
~ADSR();
int time, internalTimer, stage;
float process(float CurrentLevel, int attack, int decay, float sustain, int release, int* pKeyState);
};
#endif
ADSR.cpp
#include "ADSR.h"
ADSR::ADSR()
{
time = 0;
stage = 4;
internalTimer = 0;
}
ADSR::~ADSR()
{
}
float ADSR::process(float CurrentLevel, int attack, int decay, float sustain, int release, int* pKeyState)
{
if(stage = 1 && time >= (attack + decay + internalTimer + release))
{
time = 0;
}
while(time < attack)
{
CurrentLevel = CurrentLevel * ((1 / attack) + 1);
time++;
return CurrentLevel;
}
while(time < (attack + decay))
{
CurrentLevel = CurrentLevel * (sustain / decay);
time++;
return CurrentLevel;
}
while(time > (attack + decay))
{
CurrentLevel = CurrentLevel * 1;
internalTimer++;
return CurrentLevel;
}
while(time < (attack + decay + internalTimer + release) && *pKeyState == 2)
{
CurrentLevel = CurrentLevel * (sustain / release);
time++;
return CurrentLevel;
}
return CurrentLevel;
}
VST_Plug_in.h
//-------------------------------------------------------------------------------------------------------
// This is the most basic plug in code there is!
// All this plug in will do is apply some gain to the input
// This is done in process replacing
//-------------------------------------------------------------------------------------------------------
#ifndef __VST_Plug_in__
#define __VST_Plug_in__
#include "audioeffectx.h"
#include <math.h>
#include "ADSR.h"
const int NUMBER_OF_INPUTS = 2;
const int NUMBER_OF_OUTPUTS = 2;
const int NUMBER_OF_PROGRAMS = 1;
const int NUMBER_OF_PARAMETERS = 5;
enum
{
kGain,
kAttack,
kDecay,
kSustain,
kRelease
};
// Base frequency (A4- 440Hz) for use in generating frequency table
const float BASE_A4 = 440.0;
const double PI = 3.14159265358979323846;
//-------------------------------------------------------------------------------------------------------
class VST_Plug_in : public AudioEffectX
{
public:
VST_Plug_in (audioMasterCallback audioMaster);
~VST_Plug_in ();
virtual void processReplacing (float** inputs, float** outputs, VstInt32 sampleFrames);
virtual VstInt32 processEvents (VstEvents* events);
virtual VstInt32 canDo (char* text);
double leftSample;
double rightSample;
float frequency;
float sampleRate;
long time;
long* pTime;
float gain;
// MIDI stuff
// MIDI data : holds data about current state of MIDI (note on/off, frequency, velocity)
int keyDown; // true : key is down, false : no key down
int* pkeyDown;
long currentNote; // the MIDI note number of the last note on (key down)
float currentVelocity; // current MIDI note velocity (0 -> 1)
float *m_pfFrequencyTable; // will store a list of frequency values (for note->frequency conversion)
void noteOff ();
void noteOn (long liNote, long liVelocity);
int getAttack(float value);
int sendAttack();
int getDecay(float value);
int sendDecay();
float getSustain(float value);
float sendSustain();
int getRelease(float value);
int sendRelease();
int maxAttack, minAttack, attack, maxDecay, minDecay, decay, minRelease, maxRelease, release;
float sustain;
double partial1, partial2, partial3, partial4, partial5, partial6, partial7, partial8;
ADSR env;
virtual void setParameter (VstInt32 index, float value);
virtual float getParameter (VstInt32 index);
virtual void getParameterLabel (VstInt32 index, char* label);
virtual void getParameterDisplay (VstInt32 index, char* text);
virtual void getParameterName (VstInt32 index, char* text);
};
#endif
VST_Plug_in.cpp
//-------------------------------------------------------------------------------------------------------
// VST Plug-Ins SDK
// Version 2.4 $Date: 2005/11/15 15:14:03 $
//
// Category : VST 2.x SDK Samples
// Filename : VST_Plug_in.cpp
// Created by : Steinberg Media Technologies
// Description : a crap additive synth
//
// © 2005, Steinberg Media Technologies, All Rights Reserved
//-------------------------------------------------------------------------------------------------------
#include "VST_Plug_in.h"
//-------------------------------------------------------------------------------------------------------
AudioEffect* createEffectInstance (audioMasterCallback audioMaster)
{
return new VST_Plug_in (audioMaster);
}
//-------------------------------------------------------------------------------------------------------
VST_Plug_in::VST_Plug_in (audioMasterCallback audioMaster)
: AudioEffectX (audioMaster, NUMBER_OF_PROGRAMS, NUMBER_OF_PARAMETERS)
{
setNumInputs (NUMBER_OF_INPUTS); // stereo in
setNumOutputs (NUMBER_OF_OUTPUTS); // stereo out
setUniqueID ('Add1'); // identify
canProcessReplacing (); // supports replacing output
leftSample = 0.0;
rightSample = 0.0;
frequency = 0.0;
gain = 1.f;
currentVelocity = 0.0;
currentNote = 0;
keyDown = 2;
pkeyDown = &keyDown;
time = 0;
pTime = &time;
partial1 = partial2 = partial3 = partial4 = partial5 = partial6 = partial7 = partial8 = 0.f;
maxAttack = 2 * 192000;
minAttack = 1;
attack = 44100;
maxDecay = 192000;
minDecay = 1;
decay = 22050;
maxRelease = 4 * 192000;
minRelease = 1;
release = 96000;
sustain = 1.f;
sampleRate = getSampleRate();//get sample rate from host
ADSR env;
isSynth (); // Informs host that this is a VSTi
// initialise frequency table
m_pfFrequencyTable = new float [128] ; // 128 Midi notes
if (m_pfFrequencyTable)
{
for (int i = 0; i< 128; i++)
{
m_pfFrequencyTable[i] = BASE_A4 *powf(2.f,(i-57)/12.f) ;
}
}
}
//-------------------------------------------------------------------------------------------------------
VST_Plug_in::~VST_Plug_in ()
{
// nothing to do here
}
//-----------------------------------------------------------------------------------------
// this is where the intresting stuff happens :0
void VST_Plug_in::processReplacing (float** inputs, float** outputs, VstInt32 sampleFrames)
{
float* out1 = outputs[0];
float* out2 = outputs[1];
//ADSR env;
for(int i = 0; i < sampleFrames; i++)
{
// NEW : only send out audio if there is a note on currently
frequency = m_pfFrequencyTable[currentNote];
partial1 = (double)sin(2.0*PI*time++*(frequency/sampleRate))* 0.125;
partial2 = (double)sin(2.0*PI*time++*((2*frequency)/sampleRate))* 0.125;
partial3 = (double)sin(2.0*PI*time++*((3*frequency)/sampleRate))* 0.125;
partial4 = (double)sin(2.0*PI*time++*((4*frequency)/sampleRate))* 0.125;
partial5 = (double)sin(2.0*PI*time++*((5*frequency)/sampleRate))* 0.125;
partial6 = (double)sin(2.0*PI*time++*((6*frequency)/sampleRate))* 0.125;
partial7 = (double)sin(2.0*PI*time++*((7*frequency)/sampleRate))* 0.125;
partial8 = (double)sin(2.0*PI*time++*((8*frequency)/sampleRate))* 0.125;
leftSample = partial1 + partial2 + partial3 + partial4 + partial5 + partial6 + partial7 + partial8;
leftSample = leftSample * env.process(leftSample, attack, decay, sustain, release, pkeyDown);
leftSample = leftSample * currentVelocity;
leftSample = leftSample * gain;
rightSample = leftSample;
// write samples to output buffer
(*out1++) = leftSample;
(*out2++) = rightSample;
}
}
// NEW : overriden function, tells host what the plugin can do (see notes)
VstInt32 VST_Plug_in::canDo(char *text)
{
if (!strcmp (text, "receiveVstEvents")) // SimpleSynth can receive VST events
return 1;
if (!strcmp (text, "receiveVstMidiEvent")) // SimpleSynth can receive VST MIDI events
return 1;
return -1; // explicitly can't do; 0 => don't know
}
// NEW : this process function is called to collect incoming VST events
VstInt32 VST_Plug_in::processEvents (VstEvents* events)
{
// parse event list
for (long i = 0; i < events->numEvents; i++)
{
if ((events->events[i])->type == kVstMidiType)
{
VstMidiEvent* event = (VstMidiEvent*)events->events[i];
char* midiData = event->midiData;
long status = midiData[0] & 0xf0; // ignoring channel
if (status == 0x90 || status == 0x80) // we only look at notes
{
long note = midiData[1];
long velocity = midiData[2];
if (status == 0x80)
{
velocity = 0;
// set velocity to zero if it is a note off message
}
if (!velocity && (note == currentNote))
{
noteOff ();
}
else
{
noteOn (note, velocity);
}
}
}
}
return 1; // indicate that we wish to receive more events
}
void VST_Plug_in::noteOn(long liNote, long liVelocity)
{
keyDown = 1;
time = 0;
currentNote = liNote;
// velocity is liVelocity /127
currentVelocity = liVelocity / 127.f;
}
void VST_Plug_in::noteOff()
{
keyDown = 2;
currentVelocity = 0;
}
// this function is called whenever the fader is moved
void VST_Plug_in::setParameter (VstInt32 index, float value)
{
switch (index)
{
case kGain : gain = value;break;
case kAttack : attack = getAttack(value); break; //need vale in samples for envelope here
case kDecay : decay = getDecay(value); break;
case kSustain : sustain = getSustain(value); break;
case kRelease : release = getRelease(value); break;
}
}
//-----------------------------------------------------------------------------------------
// this function is called whenever the gui requires data
// eg when it is displayed
float VST_Plug_in::getParameter (VstInt32 index)
{
switch (index)
{
case kGain : return gain;break;
case kAttack : return sendAttack(); break; //need 0 - 1 val here
case kDecay : return sendDecay();break;
case kSustain : return sendSustain();break;
case kRelease : return sendRelease();break;
}
}
//-----------------------------------------------------------------------------------------
// getParameterName places the parameter name on the plug in
void VST_Plug_in::getParameterName (VstInt32 index, char* label)
{
switch (index)
{
case kGain : vst_strncpy (label, "Gain", kVstMaxParamStrLen);break;
case kAttack : vst_strncpy (label, "Attack", kVstMaxParamStrLen); break;
case kDecay : vst_strncpy (label, "Decay", kVstMaxParamStrLen); break;
case kSustain : vst_strncpy (label, "Sustain", kVstMaxParamStrLen); break;
case kRelease : vst_strncpy (label, "Release", kVstMaxParamStrLen); break;
}
}
//----------------------------------------------------------------------------------------
// getParameterDisplay displays the parameter value on the plug-in
void VST_Plug_in::getParameterDisplay (VstInt32 index, char* text)
{
switch (index)
{
case kGain : dB2string(gain, text, kVstMaxParamStrLen);break;
case kAttack : float2string(attack, text, kVstMaxParamStrLen); break;
case kDecay : float2string(decay, text, kVstMaxParamStrLen); break;
case kSustain: dB2string(sustain, text, kVstMaxParamStrLen); break;
case kRelease : float2string(release, text, kVstMaxParamStrLen); break;
}
//linear display
//float2string(gain, text, kVstMaxParamStrLen);
//dB display
//dB2string (gain, text, kVstMaxParamStrLen);
}
//-----------------------------------------------------------------------------------------
void VST_Plug_in::getParameterLabel (VstInt32 index, char* label)
{
switch (index)
{
case kGain : vst_strncpy (label, "dB", kVstMaxParamStrLen);break;
case kAttack : vst_strncpy (label, "Samples", kVstMaxParamStrLen); break;
case kDecay : vst_strncpy (label, "Samples", kVstMaxParamStrLen); break;
case kSustain : vst_strncpy (label, "dB", kVstMaxParamStrLen); break;
case kRelease : vst_strncpy (label, "Samples", kVstMaxParamStrLen); break;
}
}
int VST_Plug_in::getAttack(float value)
{
attack = minAttack + ((maxAttack-minAttack) * value);
return attack;
}
int VST_Plug_in::sendAttack()
{
int retAttVal;
retAttVal = (attack - minAttack) / (maxAttack-minAttack);
return retAttVal;
}
int VST_Plug_in::getDecay(float value)
{
decay = minDecay + ((maxDecay-minDecay) * value);
return decay;
}
int VST_Plug_in::sendDecay()
{
int retDecVal;
retDecVal = (decay - minDecay) / (maxDecay-minDecay);
return retDecVal;
}
float VST_Plug_in::getSustain(float value)
{
sustain = value;
return sustain;
}
float VST_Plug_in::sendSustain()
{
return sustain;
}
int VST_Plug_in::getRelease(float value)
{
release = minRelease + ((maxRelease-minRelease) * value);
return release;
}
int VST_Plug_in::sendRelease()
{
int retRelVal;
retRelVal = (release - minRelease) / (maxRelease-minRelease);
return retRelVal;
}