/* ========================================
 *  Dirt - Dirt.h
 *  Copyright (c) 2016 airwindows, Airwindows uses the MIT license
 * ======================================== */

#include "Dirt.h"

#ifdef SHR3D_SFX_CORE_AIRWINDOWS

namespace airwinconsolidated::Dirt {

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

	double overallscale = 1.0;
	overallscale /= 44100.0;
	overallscale *= getSampleRate();
	
	double inTrim = ((1.0-pow(1.0-A,2))*1.0)+1.0;
	double cutoff = (B*25000.0) / getSampleRate();
	if (cutoff > 0.49) cutoff = 0.49; //don't crash if run at 44.1k
	if (cutoff < 0.001) cutoff = 0.001; //or if cutoff's too low
	double iirAmount = pow(C,3)*0.5;
	if (iirAmount < 0.00000001) iirAmount = 0.00000001; //or if cutoff's too low
	iirAmount /= overallscale; //highpass is very gentle
	double outPad = D;
	double wet = E;
	
	fixG[fix_freq] = fixF[fix_freq] = fixE[fix_freq] = fixD[fix_freq] = fixC[fix_freq] = fixB[fix_freq] = fixA[fix_freq] = cutoff;
	
    fixA[fix_reso] = 4.46570214;
	fixB[fix_reso] = 1.51387132;
	fixC[fix_reso] = 0.93979296;
	fixD[fix_reso] = 0.70710678;
	fixE[fix_reso] = 0.59051105;
	fixF[fix_reso] = 0.52972649;
	fixG[fix_reso] = 0.50316379;
	
	double K = tan(M_PI * fixA[fix_freq]); //lowpass
	double norm = 1.0 / (1.0 + K / fixA[fix_reso] + K * K);
	fixA[fix_a0] = K * K * norm;
	fixA[fix_a1] = 2.0 * fixA[fix_a0];
	fixA[fix_a2] = fixA[fix_a0];
	fixA[fix_b1] = 2.0 * (K * K - 1.0) * norm;
	fixA[fix_b2] = (1.0 - K / fixA[fix_reso] + K * K) * norm;
	
	K = tan(M_PI * fixB[fix_freq]);
	norm = 1.0 / (1.0 + K / fixB[fix_reso] + K * K);
	fixB[fix_a0] = K * K * norm;
	fixB[fix_a1] = 2.0 * fixB[fix_a0];
	fixB[fix_a2] = fixB[fix_a0];
	fixB[fix_b1] = 2.0 * (K * K - 1.0) * norm;
	fixB[fix_b2] = (1.0 - K / fixB[fix_reso] + K * K) * norm;
	
	K = tan(M_PI * fixC[fix_freq]);
	norm = 1.0 / (1.0 + K / fixC[fix_reso] + K * K);
	fixC[fix_a0] = K * K * norm;
	fixC[fix_a1] = 2.0 * fixC[fix_a0];
	fixC[fix_a2] = fixC[fix_a0];
	fixC[fix_b1] = 2.0 * (K * K - 1.0) * norm;
	fixC[fix_b2] = (1.0 - K / fixC[fix_reso] + K * K) * norm;
	
	K = tan(M_PI * fixD[fix_freq]);
	norm = 1.0 / (1.0 + K / fixD[fix_reso] + K * K);
	fixD[fix_a0] = K * K * norm;
	fixD[fix_a1] = 2.0 * fixD[fix_a0];
	fixD[fix_a2] = fixD[fix_a0];
	fixD[fix_b1] = 2.0 * (K * K - 1.0) * norm;
	fixD[fix_b2] = (1.0 - K / fixD[fix_reso] + K * K) * norm;
	
	K = tan(M_PI * fixE[fix_freq]);
	norm = 1.0 / (1.0 + K / fixE[fix_reso] + K * K);
	fixE[fix_a0] = K * K * norm;
	fixE[fix_a1] = 2.0 * fixE[fix_a0];
	fixE[fix_a2] = fixE[fix_a0];
	fixE[fix_b1] = 2.0 * (K * K - 1.0) * norm;
	fixE[fix_b2] = (1.0 - K / fixE[fix_reso] + K * K) * norm;
	
	K = tan(M_PI * fixF[fix_freq]);
	norm = 1.0 / (1.0 + K / fixF[fix_reso] + K * K);
	fixF[fix_a0] = K * K * norm;
	fixF[fix_a1] = 2.0 * fixF[fix_a0];
	fixF[fix_a2] = fixF[fix_a0];
	fixF[fix_b1] = 2.0 * (K * K - 1.0) * norm;
	fixF[fix_b2] = (1.0 - K / fixF[fix_reso] + K * K) * norm;
	
	K = tan(M_PI * fixG[fix_freq]);
	norm = 1.0 / (1.0 + K / fixG[fix_reso] + K * K);
	fixG[fix_a0] = K * K * norm;
	fixG[fix_a1] = 2.0 * fixG[fix_a0];
	fixG[fix_a2] = fixG[fix_a0];
	fixG[fix_b1] = 2.0 * (K * K - 1.0) * norm;
	fixG[fix_b2] = (1.0 - K / fixG[fix_reso] + K * K) * norm;
    
    while (--sampleFrames >= 0)
    {
		double inputSampleL = *in1;
		double inputSampleR = *in2;
		double drySampleL = inputSampleL;
		double drySampleR = inputSampleR;
		if (fabs(inputSampleL)<1.18e-23) inputSampleL = fpdL * 1.18e-17;
		if (fabs(inputSampleR)<1.18e-23) inputSampleR = fpdR * 1.18e-17;
		
		if (fabs(iirSampleL)<1.18e-33) iirSampleL = 0.0;
		iirSampleL = (iirSampleL * (1.0 - iirAmount)) + (inputSampleL * iirAmount);
		inputSampleL = inputSampleL - iirSampleL;
		
		if (fabs(iirSampleR)<1.18e-33) iirSampleR = 0.0;
		iirSampleR = (iirSampleR * (1.0 - iirAmount)) + (inputSampleR * iirAmount);
		inputSampleR = inputSampleR - iirSampleR;		
		
		if (inputSampleL > 1.0) inputSampleL = 1.0; if (inputSampleL < -1.0) inputSampleL = -1.0;
		if (inputSampleR > 1.0) inputSampleR = 1.0; if (inputSampleR < -1.0) inputSampleR = -1.0;
				
		double outSample = (inputSampleL * fixA[fix_a0]) + fixA[fix_sL1];
		fixA[fix_sL1] = (inputSampleL * fixA[fix_a1]) - (outSample * fixA[fix_b1]) + fixA[fix_sL2];
		fixA[fix_sL2] = (inputSampleL * fixA[fix_a2]) - (outSample * fixA[fix_b2]);
		inputSampleL = outSample; //fixed biquad filtering ultrasonics L
		outSample = (inputSampleR * fixA[fix_a0]) + fixA[fix_sR1];
		fixA[fix_sR1] = (inputSampleR * fixA[fix_a1]) - (outSample * fixA[fix_b1]) + fixA[fix_sR2];
		fixA[fix_sR2] = (inputSampleR * fixA[fix_a2]) - (outSample * fixA[fix_b2]);
		inputSampleR = outSample; //fixed biquad filtering ultrasonics R
		
		inputSampleL = (inputSampleL-(inputSampleL*fabs(inputSampleL)*0.5))*inTrim;
		inputSampleR = (inputSampleR-(inputSampleR*fabs(inputSampleR)*0.5))*inTrim;
		
		outSample = (inputSampleL * fixB[fix_a0]) + fixB[fix_sL1];
		fixB[fix_sL1] = (inputSampleL * fixB[fix_a1]) - (outSample * fixB[fix_b1]) + fixB[fix_sL2];
		fixB[fix_sL2] = (inputSampleL * fixB[fix_a2]) - (outSample * fixB[fix_b2]);
		inputSampleL = outSample; //fixed biquad filtering ultrasonics L
		outSample = (inputSampleR * fixB[fix_a0]) + fixB[fix_sR1];
		fixB[fix_sR1] = (inputSampleR * fixB[fix_a1]) - (outSample * fixB[fix_b1]) + fixB[fix_sR2];
		fixB[fix_sR2] = (inputSampleR * fixB[fix_a2]) - (outSample * fixB[fix_b2]);
		inputSampleR = outSample; //fixed biquad filtering ultrasonics R
		
		inputSampleL = (inputSampleL-(inputSampleL*fabs(inputSampleL)*0.5))*inTrim;
		inputSampleR = (inputSampleR-(inputSampleR*fabs(inputSampleR)*0.5))*inTrim;
		
		outSample = (inputSampleL * fixC[fix_a0]) + fixC[fix_sL1];
		fixC[fix_sL1] = (inputSampleL * fixC[fix_a1]) - (outSample * fixC[fix_b1]) + fixC[fix_sL2];
		fixC[fix_sL2] = (inputSampleL * fixC[fix_a2]) - (outSample * fixC[fix_b2]);
		inputSampleL = outSample; //fixed biquad filtering ultrasonics L
		outSample = (inputSampleR * fixC[fix_a0]) + fixC[fix_sR1];
		fixC[fix_sR1] = (inputSampleR * fixC[fix_a1]) - (outSample * fixC[fix_b1]) + fixC[fix_sR2];
		fixC[fix_sR2] = (inputSampleR * fixC[fix_a2]) - (outSample * fixC[fix_b2]);
		inputSampleR = outSample; //fixed biquad filtering ultrasonics R
		
		inputSampleL = (inputSampleL-(inputSampleL*fabs(inputSampleL)*0.5))*inTrim;
		inputSampleR = (inputSampleR-(inputSampleR*fabs(inputSampleR)*0.5))*inTrim;
		
		outSample = (inputSampleL * fixD[fix_a0]) + fixD[fix_sL1];
		fixD[fix_sL1] = (inputSampleL * fixD[fix_a1]) - (outSample * fixD[fix_b1]) + fixD[fix_sL2];
		fixD[fix_sL2] = (inputSampleL * fixD[fix_a2]) - (outSample * fixD[fix_b2]);
		inputSampleL = outSample; //fixed biquad filtering ultrasonics L
		outSample = (inputSampleR * fixD[fix_a0]) + fixD[fix_sR1];
		fixD[fix_sR1] = (inputSampleR * fixD[fix_a1]) - (outSample * fixD[fix_b1]) + fixD[fix_sR2];
		fixD[fix_sR2] = (inputSampleR * fixD[fix_a2]) - (outSample * fixD[fix_b2]);
		inputSampleR = outSample; //fixed biquad filtering ultrasonics R
		
		inputSampleL = (inputSampleL-(inputSampleL*fabs(inputSampleL)*0.5))*inTrim;
		inputSampleR = (inputSampleR-(inputSampleR*fabs(inputSampleR)*0.5))*inTrim;
		
		outSample = (inputSampleL * fixE[fix_a0]) + fixE[fix_sL1];
		fixE[fix_sL1] = (inputSampleL * fixE[fix_a1]) - (outSample * fixE[fix_b1]) + fixE[fix_sL2];
		fixE[fix_sL2] = (inputSampleL * fixE[fix_a2]) - (outSample * fixE[fix_b2]);
		inputSampleL = outSample; //fixed biquad filtering ultrasonics L
		outSample = (inputSampleR * fixE[fix_a0]) + fixE[fix_sR1];
		fixE[fix_sR1] = (inputSampleR * fixE[fix_a1]) - (outSample * fixE[fix_b1]) + fixE[fix_sR2];
		fixE[fix_sR2] = (inputSampleR * fixE[fix_a2]) - (outSample * fixE[fix_b2]);
		inputSampleR = outSample; //fixed biquad filtering ultrasonics R
		
		inputSampleL = (inputSampleL-(inputSampleL*fabs(inputSampleL)*0.5))*inTrim;
		inputSampleR = (inputSampleR-(inputSampleR*fabs(inputSampleR)*0.5))*inTrim;
		
		outSample = (inputSampleL * fixF[fix_a0]) + fixF[fix_sL1];
		fixF[fix_sL1] = (inputSampleL * fixF[fix_a1]) - (outSample * fixF[fix_b1]) + fixF[fix_sL2];
		fixF[fix_sL2] = (inputSampleL * fixF[fix_a2]) - (outSample * fixF[fix_b2]);
		inputSampleL = outSample; //fixed biquad filtering ultrasonics L
		outSample = (inputSampleR * fixF[fix_a0]) + fixF[fix_sR1];
		fixF[fix_sR1] = (inputSampleR * fixF[fix_a1]) - (outSample * fixF[fix_b1]) + fixF[fix_sR2];
		fixF[fix_sR2] = (inputSampleR * fixF[fix_a2]) - (outSample * fixF[fix_b2]);
		inputSampleR = outSample; //fixed biquad filtering ultrasonics R
		
		inputSampleL = (inputSampleL-(inputSampleL*fabs(inputSampleL)*0.5))*inTrim;
		inputSampleR = (inputSampleR-(inputSampleR*fabs(inputSampleR)*0.5))*inTrim;
		
		outSample = (inputSampleL * fixG[fix_a0]) + fixG[fix_sL1];
		fixG[fix_sL1] = (inputSampleL * fixG[fix_a1]) - (outSample * fixG[fix_b1]) + fixG[fix_sL2];
		fixG[fix_sL2] = (inputSampleL * fixG[fix_a2]) - (outSample * fixG[fix_b2]);
		inputSampleL = outSample; //fixed biquad filtering ultrasonics L
		outSample = (inputSampleR * fixG[fix_a0]) + fixG[fix_sR1];
		fixG[fix_sR1] = (inputSampleR * fixG[fix_a1]) - (outSample * fixG[fix_b1]) + fixG[fix_sR2];
		fixG[fix_sR2] = (inputSampleR * fixG[fix_a2]) - (outSample * fixG[fix_b2]);
		inputSampleR = outSample; //fixed biquad filtering ultrasonics R
		
		inputSampleL = (inputSampleL * wet * outPad) + (drySampleL * (1.0-wet));
		inputSampleR = (inputSampleR * wet * outPad) + (drySampleR * (1.0-wet));
		
		//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
