/* ========================================
 *  Stonefire - Stonefire.h
 *  Copyright (c) airwindows, Airwindows uses the MIT license
 * ======================================== */

#include "Stonefire.h"

#ifdef SHR3D_SFX_CORE_AIRWINDOWS

namespace airwinconsolidated::Stonefire {

void Stonefire::processBlock(float **inputs, float **outputs, int sampleFrames) 
{
    float* in1  =  inputs[0];
    float* in2  =  inputs[1];
    float* out1 = outputs[0];
    float* out2 = outputs[1];

	int inFramesToProcess = sampleFrames; //vst doesn't give us this as a separate variable so we'll make it
	double overallscale = 1.0;
	overallscale /= 44100.0;
	overallscale *= getSampleRate();
	trebleGainA = trebleGainB; trebleGainB = A*2.0;
	midGainA = midGainB; midGainB = B*2.0;
	bassGainA = bassGainB; bassGainB = C*2.0;
	//simple three band to adjust
	double kalman = 1.0-pow(D,2);
	//crossover frequency between mid/bass
    
    while (--sampleFrames >= 0)
    {
		double inputSampleL = *in1;
		double inputSampleR = *in2;
		if (fabs(inputSampleL)<1.18e-23) inputSampleL = fpdL * 1.18e-17;
		if (fabs(inputSampleR)<1.18e-23) inputSampleR = fpdR * 1.18e-17;
		double drySampleL = inputSampleL;
		double drySampleR = inputSampleR;
		
		double temp = (double)sampleFrames/inFramesToProcess;
		double trebleGain = (trebleGainA*temp)+(trebleGainB*(1.0-temp));
		if (trebleGain > 1.0) trebleGain = pow(trebleGain,3.0+sqrt(overallscale));
		if (trebleGain < 1.0) trebleGain = 1.0-pow(1.0-trebleGain,2);
		
		double midGain = (midGainA*temp)+(midGainB*(1.0-temp));
		if (midGain > 1.0) midGain *= midGain;
		if (midGain < 1.0) midGain = 1.0-pow(1.0-midGain,2);
		
		double bassGain = (bassGainA*temp)+(bassGainB*(1.0-temp));
		if (bassGain > 1.0) bassGain *= bassGain;
		if (bassGain < 1.0) bassGain = 1.0-pow(1.0-bassGain,2);
				
		//begin Air3L
		air[pvSL4] = air[pvAL4] - air[pvAL3]; air[pvSL3] = air[pvAL3] - air[pvAL2];
		air[pvSL2] = air[pvAL2] - air[pvAL1]; air[pvSL1] = air[pvAL1] - inputSampleL;
		air[accSL3] = air[pvSL4] - air[pvSL3]; air[accSL2] = air[pvSL3] - air[pvSL2];
		air[accSL1] = air[pvSL2] - air[pvSL1];
		air[acc2SL2] = air[accSL3] - air[accSL2]; air[acc2SL1] = air[accSL2] - air[accSL1];		
		air[outAL] = -(air[pvAL1] + air[pvSL3] + air[acc2SL2] - ((air[acc2SL2] + air[acc2SL1])*0.5));
		air[gainAL] *= 0.5; air[gainAL] += fabs(drySampleL-air[outAL])*0.5;
		if (air[gainAL] > 0.3*sqrt(overallscale)) air[gainAL] = 0.3*sqrt(overallscale);
		air[pvAL4] = air[pvAL3]; air[pvAL3] = air[pvAL2];
		air[pvAL2] = air[pvAL1]; air[pvAL1] = (air[gainAL] * air[outAL]) + drySampleL;
		double midL = drySampleL - ((air[outAL]*0.5)+(drySampleL*(0.457-(0.017*overallscale))));
		temp = (midL + air[gndavgL])*0.5; air[gndavgL] = midL; midL = temp;
		double trebleL = drySampleL-midL;
		inputSampleL = midL;
		//end Air3L
		
		//begin Air3R
		air[pvSR4] = air[pvAR4] - air[pvAR3]; air[pvSR3] = air[pvAR3] - air[pvAR2];
		air[pvSR2] = air[pvAR2] - air[pvAR1]; air[pvSR1] = air[pvAR1] - inputSampleR;
		air[accSR3] = air[pvSR4] - air[pvSR3]; air[accSR2] = air[pvSR3] - air[pvSR2];
		air[accSR1] = air[pvSR2] - air[pvSR1];
		air[acc2SR2] = air[accSR3] - air[accSR2]; air[acc2SR1] = air[accSR2] - air[accSR1];		
		air[outAR] = -(air[pvAR1] + air[pvSR3] + air[acc2SR2] - ((air[acc2SR2] + air[acc2SR1])*0.5));
		air[gainAR] *= 0.5; air[gainAR] += fabs(drySampleR-air[outAR])*0.5;
		if (air[gainAR] > 0.3*sqrt(overallscale)) air[gainAR] = 0.3*sqrt(overallscale);
		air[pvAR4] = air[pvAR3]; air[pvAR3] = air[pvAR2];
		air[pvAR2] = air[pvAR1]; air[pvAR1] = (air[gainAR] * air[outAR]) + drySampleR;
		double midR = drySampleR - ((air[outAR]*0.5)+(drySampleR*(0.457-(0.017*overallscale))));
		temp = (midR + air[gndavgR])*0.5; air[gndavgR] = midR; midR = temp;
		double trebleR = drySampleR-midR;
		inputSampleR = midR;
		//end Air3R
		
		//begin KalmanL
		temp = inputSampleL = inputSampleL*(1.0-kalman)*0.777;
		inputSampleL *= (1.0-kalman);
		//set up gain levels to control the beast
		kal[prevSlewL3] += kal[prevSampL3] - kal[prevSampL2]; kal[prevSlewL3] *= 0.5;
		kal[prevSlewL2] += kal[prevSampL2] - kal[prevSampL1]; kal[prevSlewL2] *= 0.5;
		kal[prevSlewL1] += kal[prevSampL1] - inputSampleL; kal[prevSlewL1] *= 0.5;
		//make slews from each set of samples used
		kal[accSlewL2] += kal[prevSlewL3] - kal[prevSlewL2]; kal[accSlewL2] *= 0.5;
		kal[accSlewL1] += kal[prevSlewL2] - kal[prevSlewL1]; kal[accSlewL1] *= 0.5;
		//differences between slews: rate of change of rate of change
		kal[accSlewL3] += (kal[accSlewL2] - kal[accSlewL1]); kal[accSlewL3] *= 0.5;
		//entering the abyss, what even is this
		kal[kalOutL] += kal[prevSampL1] + kal[prevSlewL2] + kal[accSlewL3]; kal[kalOutL] *= 0.5;
		//resynthesizing predicted result (all iir smoothed)
		kal[kalGainL] += fabs(temp-kal[kalOutL])*kalman*8.0; kal[kalGainL] *= 0.5;
		//madness takes its toll. Kalman Gain: how much dry to retain
		if (kal[kalGainL] > kalman*0.5) kal[kalGainL] = kalman*0.5;
		//attempts to avoid explosions
		kal[kalOutL] += (temp*(1.0-(0.68+(kalman*0.157))));	
		//this is for tuning a really complete cancellation up around Nyquist
		kal[prevSampL3] = kal[prevSampL2]; kal[prevSampL2] = kal[prevSampL1];
		kal[prevSampL1] = (kal[kalGainL] * kal[kalOutL]) + ((1.0-kal[kalGainL])*temp);
		//feed the chain of previous samples
		if (kal[prevSampL1] > 1.0) kal[prevSampL1] = 1.0; if (kal[prevSampL1] < -1.0) kal[prevSampL1] = -1.0;
		double bassL = kal[kalOutL]*0.777;
		midL -= bassL;
		//end KalmanL
		
		//begin KalmanR
		temp = inputSampleR = inputSampleR*(1.0-kalman)*0.777;
		inputSampleR *= (1.0-kalman);
		//set up gain levels to control the beast
		kal[prevSlewR3] += kal[prevSampR3] - kal[prevSampR2]; kal[prevSlewR3] *= 0.5;
		kal[prevSlewR2] += kal[prevSampR2] - kal[prevSampR1]; kal[prevSlewR2] *= 0.5;
		kal[prevSlewR1] += kal[prevSampR1] - inputSampleR; kal[prevSlewR1] *= 0.5;
		//make slews from each set of samples used
		kal[accSlewR2] += kal[prevSlewR3] - kal[prevSlewR2]; kal[accSlewR2] *= 0.5;
		kal[accSlewR1] += kal[prevSlewR2] - kal[prevSlewR1]; kal[accSlewR1] *= 0.5;
		//differences between slews: rate of change of rate of change
		kal[accSlewR3] += (kal[accSlewR2] - kal[accSlewR1]); kal[accSlewR3] *= 0.5;
		//entering the abyss, what even is this
		kal[kalOutR] += kal[prevSampR1] + kal[prevSlewR2] + kal[accSlewR3]; kal[kalOutR] *= 0.5;
		//resynthesizing predicted result (all iir smoothed)
		kal[kalGainR] += fabs(temp-kal[kalOutR])*kalman*8.0; kal[kalGainR] *= 0.5;
		//madness takes its toll. Kalman Gain: how much dry to retain
		if (kal[kalGainR] > kalman*0.5) kal[kalGainR] = kalman*0.5;
		//attempts to avoid explosions
		kal[kalOutR] += (temp*(1.0-(0.68+(kalman*0.157))));	
		//this is for tuning a really complete cancellation up around Nyquist
		kal[prevSampR3] = kal[prevSampR2]; kal[prevSampR2] = kal[prevSampR1];
		kal[prevSampR1] = (kal[kalGainR] * kal[kalOutR]) + ((1.0-kal[kalGainR])*temp);
		//feed the chain of previous samples
		if (kal[prevSampR1] > 1.0) kal[prevSampR1] = 1.0; if (kal[prevSampR1] < -1.0) kal[prevSampR1] = -1.0;
		double bassR = kal[kalOutR]*0.777;
		midR -= bassR;
		//end KalmanR
				
		inputSampleL = (bassL*bassGain) + (midL*midGain) + (trebleL*trebleGain);
		inputSampleR = (bassR*bassGain) + (midR*midGain) + (trebleR*trebleGain);
		//applies pan section, and smoothed fader gain
		
		//begin 32 bit stereo floating point dither
		int expon; frexpf((float)inputSampleL, &expon);
		fpdL ^= fpdL << 13; fpdL ^= fpdL >> 17; fpdL ^= fpdL << 5;
		inputSampleL += double((double(fpdL)-uint32_t(0x7fffffff)) * 5.5e-36l * pow(2.0,expon+62.0));
		frexpf((float)inputSampleR, &expon);
		fpdR ^= fpdR << 13; fpdR ^= fpdR >> 17; fpdR ^= fpdR << 5;
		inputSampleR += double((double(fpdR)-uint32_t(0x7fffffff)) * 5.5e-36l * pow(2.0,expon+62.0));
		//end 32 bit stereo floating point dither
		
		*out1 = float(inputSampleL);
		*out2 = float(inputSampleR);

		in1++;
		in2++;
		out1++;
		out2++;
    }
}

} // end namespace

#endif // SHR3D_SFX_CORE_AIRWINDOWS
