/*

Copyright (C) 2016 Apple Inc. All Rights Reserved.

See LICENSE.txt for this sample’s licensing information

Abstract:

Instrument AU

*/

/*

    This is a test implementation of a sin wave synth using AUInstrumentBase classes

    It illustrates a basic usage of these classes

    It artificially limits the number of notes at one time to 12, so the note-stealing 

    algorithm is used - you should know how this works!

    Most of the work you need to do is defining a Note class (see TestNote). AUInstrument manages the

    creation and destruction of notes, the various stages of a note's lifetime.

    Alot of printfs have been left in (but are if'def out)

    These can be useful as you figure out how this all fits together. This is true in the AUInstrumentBase

    classes as well; simply define DEBUG_PRINT to 1 and this turns all this on

    The project also defines CA_AUTO_MIDI_MAP (OTHER_C_FLAGS). This adds all the code that is needed

    to map MIDI messages to specific parameter changes. This can be seen in AU Lab's MIDI Editor window

    CA_AUTO_MIDI_MAP is implemented in AUMIDIBase.cpp/.h

*/

#include "SinSynth.h"

static const UInt32 kMaxActiveNotes = 8;

/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

const double twopi = 2.0 * 3.14159265358979;

inline double pow5(double x) { double x2 = x*x; return x2*x2*x; }

#pragma mark SinSynth Methods

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

//COMPONENT_ENTRY(SinSynth)

AUDIOCOMPONENT_ENTRY(AUMusicDeviceFactory, SinSynth)

static const AudioUnitParameterID kGlobalVolumeParam = 0;

static const CFStringRef kGlobalVolumeName = CFSTR("global volume");

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

//  SinSynth::SinSynth

//

// This synth has No inputs, One output

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

SinSynth::SinSynth(AudioUnit inComponentInstance)

    : AUMonotimbralInstrumentBase(inComponentInstance, 0, 1)

{

    CreateElements();

    Globals()->UseIndexedParameters(1); // we're only defining one param

    Globals()->SetParameter (kGlobalVolumeParam, 1.0);

}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

//  SinSynth::~SinSynth

//

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

SinSynth::~SinSynth()

{

}

void SinSynth::Cleanup()

{

#if DEBUG_PRINT

    printf("SinSynth::Cleanup\n");

#endif

}

OSStatus SinSynth::Initialize()

{   

#if DEBUG_PRINT

    printf("->SinSynth::Initialize\n");

#endif

    AUMonotimbralInstrumentBase::Initialize();

    SetNotes(kNumNotes, kMaxActiveNotes, mTestNotes, sizeof(TestNote));

#if DEBUG_PRINT

    printf("<-SinSynth::Initialize\n");

#endif

    return noErr;

}

AUElement* SinSynth::CreateElement( AudioUnitScope                  scope,

                                    AudioUnitElement                element)

{

    switch (scope)

    {

        case kAudioUnitScope_Group :

            return new SynthGroupElement(this, element, new MidiControls);

        case kAudioUnitScope_Part :

            return new SynthPartElement(this, element);

        default :

            return AUBase::CreateElement(scope, element);

    }

}

OSStatus            SinSynth::GetParameterInfo(     AudioUnitScope                  inScope,

                                                        AudioUnitParameterID            inParameterID,

                                                        AudioUnitParameterInfo &        outParameterInfo)

{

    if (inParameterID != kGlobalVolumeParam) return kAudioUnitErr_InvalidParameter;

    if (inScope != kAudioUnitScope_Global) return kAudioUnitErr_InvalidScope;

    outParameterInfo.flags = SetAudioUnitParameterDisplayType (0, kAudioUnitParameterFlag_DisplaySquareRoot);

    outParameterInfo.flags += kAudioUnitParameterFlag_IsWritable;

    outParameterInfo.flags += kAudioUnitParameterFlag_IsReadable;

    AUBase::FillInParameterName (outParameterInfo, kGlobalVolumeName, false);

    outParameterInfo.unit = kAudioUnitParameterUnit_LinearGain;

    outParameterInfo.minValue = 0;

    outParameterInfo.maxValue = 1.0;

    outParameterInfo.defaultValue = 1.0;

    return noErr;

}

#pragma mark TestNote Methods

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

void            TestNote::Release(UInt32 inFrame)

{

    SynthNote::Release(inFrame);

#if DEBUG_PRINT

    printf("TestNote::Release %p %d\n", this, GetState());

#endif

}

void            TestNote::FastRelease(UInt32 inFrame) // voice is being stolen.

{

    SynthNote::Release(inFrame);

#if DEBUG_PRINT

    printf("TestNote::Release %p %d\n", this, GetState());

#endif

}

void            TestNote::Kill(UInt32 inFrame) // voice is being stolen.

{

    SynthNote::Kill(inFrame);

#if DEBUG_PRINT

    printf("TestNote::Kill %p %d\n", this, GetState());

#endif

}

OSStatus        TestNote::Render(UInt64 inAbsoluteSampleFrame, UInt32 inNumFrames, AudioBufferList** inBufferList, UInt32 inOutBusCount)

{

    float *left, *right;

/* ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~  

    Changes to this parameter (kGlobalVolumeParam) are not being de-zippered; 

    Left as an exercise for the reader

 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ */

    float globalVol = GetGlobalParameter(kGlobalVolumeParam);

    // TestNote only writes into the first bus regardless of what is handed to us.

    const int bus0 = 0;

    int numChans = inBufferList[bus0]->mNumberBuffers;

    if (numChans > 2) return -1;

    left = (float*)inBufferList[bus0]->mBuffers[0].mData;

    right = numChans == 2 ? (float*)inBufferList[bus0]->mBuffers[1].mData : 0;

    double sampleRate = SampleRate();

    double freq = Frequency() * (twopi/sampleRate);

#if DEBUG_PRINT_RENDER

    printf("TestNote::Render %p %d %g %g\n", this, GetState(), phase, amp);

#endif

    switch (GetState())

    {

        case kNoteState_Attacked :

        case kNoteState_Sostenutoed :

        case kNoteState_ReleasedButSostenutoed :

        case kNoteState_ReleasedButSustained :

            {

                for (UInt32 frame=0; frame<inNumFrames; ++frame)

                {

                    if (amp < maxamp) amp += up_slope;

                    float out = pow5(sin(phase)) * amp * globalVol;

                    phase += freq;

                    if (phase > twopi) phase -= twopi;

                    left[frame] += out;

                    if (right) right[frame] += out;

                }

            }

            break;

        case kNoteState_Released :

            {

                UInt32 endFrame = 0xFFFFFFFF;

                for (UInt32 frame=0; frame<inNumFrames; ++frame)

                {

                    if (amp > 0.0) amp += dn_slope;

                    else if (endFrame == 0xFFFFFFFF) endFrame = frame;

                    float out = pow5(sin(phase)) * amp * globalVol;

                    phase += freq;

                    left[frame] += out;

                    if (right) right[frame] += out;

                }

                if (endFrame != 0xFFFFFFFF) {

#if DEBUG_PRINT

                    printf("TestNote::NoteEnded  %p %d %g %g\n", this, GetState(), phase, amp);

#endif

                    NoteEnded(endFrame);

                }

            }

            break;

        case kNoteState_FastReleased :

            {

                UInt32 endFrame = 0xFFFFFFFF;

                for (UInt32 frame=0; frame<inNumFrames; ++frame)

                {

                    if (amp > 0.0) amp += fast_dn_slope;

                    else if (endFrame == 0xFFFFFFFF) endFrame = frame;

                    float out = pow5(sin(phase)) * amp * globalVol;

                    phase += freq;

                    left[frame] += out;

                    if (right) right[frame] += out;

                }

                if (endFrame != 0xFFFFFFFF) {

#if DEBUG_PRINT

                    printf("TestNote::NoteEnded  %p %d %g %g\n", this, GetState(), phase, amp);

#endif

                    NoteEnded(endFrame);

                }

            }

            break;

        default :

            break;

    }

    return noErr;

}