/*
  Copyright (c) 2021 Alex Diener
  
  This software is provided 'as-is', without any express or implied
  warranty. In no event will the authors be held liable for any damages
  arising from the use of this software.
  
  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:
  
  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
  
  Alex Diener alex@ludobloom.com
*/

#include "audiosynth/SignalFilter_bitcrush.h"
#include "utilities/lookup3.h"
#include <math.h>

#define stemobject_implementation SignalFilter_bitcrush

stemobject_vtable_begin();
stemobject_vtable_entry(dispose);
stemobject_vtable_entry(copy);
stemobject_vtable_entry(isEqual);
stemobject_vtable_entry(hash);
stemobject_vtable_entry(initState);
stemobject_vtable_entry(disposeState);
stemobject_vtable_entry(getPropertyCount);
stemobject_vtable_entry(getPropertyAtIndex);
stemobject_vtable_entry(getPropertyValueStateless);
stemobject_vtable_entry(setPropertyValue);
stemobject_vtable_entry(transformSample);
stemobject_vtable_end();

SignalFilter_bitcrush * SignalFilter_bitcrush_create(float numericResolution, float temporalResolution) {
	stemobject_create_implementation(init, numericResolution, temporalResolution)
}

bool SignalFilter_bitcrush_init(SignalFilter_bitcrush * self, float numericResolution, float temporalResolution) {
	call_super(init, self);
	self->numericResolution = numericResolution;
	self->temporalResolution = temporalResolution;
	return true;
}

void SignalFilter_bitcrush_dispose(SignalFilter_bitcrush * self) {
	call_super_virtual(dispose, self);
}

SignalFilter_bitcrush * SignalFilter_bitcrush_copy(SignalFilter_bitcrush * self) {
	stemobject_copy_implementation(initCopy)
}

bool SignalFilter_bitcrush_isEqual(SignalFilter_bitcrush * self, compat_type(SignalFilter_bitcrush *) compareUntyped) {
	SignalFilter_bitcrush * compare = compareUntyped;
	if (!call_super_virtual(isEqual, self, compare)) {
		return false;
	}
	return compare->numericResolution == self->numericResolution &&
	       compare->temporalResolution == self->temporalResolution;
}

uint32_t SignalFilter_bitcrush_hash(SignalFilter_bitcrush * self, uint32_t initval) {
	initval = hashlittle(&self->numericResolution, sizeof(self->numericResolution), initval);
	initval = hashlittle(&self->temporalResolution, sizeof(self->temporalResolution), initval);
	return initval;
}

void SignalFilter_bitcrush_initCopy(SignalFilter_bitcrush * self, SignalFilter_bitcrush * original) {
	call_super(initCopy, self, (SignalFilter *) original);
	self->numericResolution = original->numericResolution;
	self->temporalResolution = original->temporalResolution;
}

#define PROPERTY_INDEX_NUMERIC_RESOLUTION 0
#define PROPERTY_INDEX_TEMPORAL_RESOLUTION 1

struct SignalFilter_bitcrush_state {
	float properties[2];
	float lastSample;
	float lastSampleUpdateTime;
};

SamplerObject_state * SignalFilter_bitcrush_initState(SignalFilter_bitcrush * self) {
	struct SignalFilter_bitcrush_state * stateStruct = malloc(sizeof(*stateStruct));
	stateStruct->properties[PROPERTY_INDEX_NUMERIC_RESOLUTION] = self->numericResolution;
	stateStruct->properties[PROPERTY_INDEX_TEMPORAL_RESOLUTION] = self->temporalResolution;
	stateStruct->lastSample = 0.0f;
	stateStruct->lastSampleUpdateTime = -1.0;
	return stateStruct;
}

void SignalFilter_bitcrush_disposeState(SignalFilter_bitcrush * self, SamplerObject_state * state) {
	free(state);
}

static SynthProperty synthProperties[2];

static void initSynthProperties(void) {
	SYNTH_PROPERTY(0, numericResolution,  "Numeric resolution",  0.0f, 16.0f, 16.0f, 1.0f)
	SYNTH_PROPERTY(1, temporalResolution, "Temporal resolution", 0.0f, 16.0f, 16.0f, 1.0f)
}

SYNTH_PROPERTY_FUNCTION_IMPLEMENTATIONS()

float SignalFilter_bitcrush_getPropertyValueStateless(SignalFilter_bitcrush * self, SynthPropertyIdentifier propertyIdentifier) {
	switch (propertyIdentifier.propertyIndex) {
		case 0:
			return self->numericResolution;
		case 1:
			return self->temporalResolution;
	}
	return 0.0f;
}

void SignalFilter_bitcrush_setPropertyValue(SignalFilter_bitcrush * self, SamplerObject_state * state, SynthPropertyIdentifier propertyIdentifier, float value) {
	struct SignalFilter_bitcrush_state * stateStruct = state;
	stateStruct->properties[propertyIdentifier.propertyIndex] = value;
}

float SignalFilter_bitcrush_transformSample(SignalFilter_bitcrush * self, SamplerObject_state * state, float sample, float time, float timeDelta) {
	struct SignalFilter_bitcrush_state * stateStruct = state;
	float timePerUpdate = powf(1.5f, 16.0f - stateStruct->properties[PROPERTY_INDEX_TEMPORAL_RESOLUTION]) / 44100;
	if (time > stateStruct->lastSampleUpdateTime + timePerUpdate) {
		float numberRange = powf(2.0f, stateStruct->properties[PROPERTY_INDEX_NUMERIC_RESOLUTION]);
		sample = roundf(sample * numberRange) / numberRange;
		stateStruct->lastSample = sample;
		stateStruct->lastSampleUpdateTime += time - stateStruct->lastSampleUpdateTime - fmod(time - stateStruct->lastSampleUpdateTime, timePerUpdate);
	}
	return stateStruct->lastSample;
}