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

#include "Distortion.h"

#ifdef SHR3D_SFX_CORE_AIRWINDOWS

namespace airwinconsolidated::Distortion {

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

	int stages = (int)floor(getSampleRate()/25000.0);
	if (stages > 8) stages = 8;
	double input = pow(10.0,((A-0.5)*24.0)/20.0);
	int mode = (int) ( B * 4.999 );
	double output = pow(10.0,((C-0.5)*24.0)/20.0);
	double wet = D;
    
    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;
		
		inputSampleL *= input;
		inputSampleR *= input;
		
		for (int x = 0; x < stages; x++) {
			double temp;
			temp = (inputSampleL+previousInL[x])*0.5;
			previousInL[x] = inputSampleL;
			inputSampleL = temp;
			temp = (inputSampleR+previousInR[x])*0.5;
			previousInR[x] = inputSampleR;
			inputSampleR = temp;
		}
		
		switch (mode)
		{
			case 0: //Density
				if (inputSampleL > 1.570796326794897) inputSampleL = 1.570796326794897;
				if (inputSampleL < -1.570796326794897) inputSampleL = -1.570796326794897;
				if (inputSampleR > 1.570796326794897) inputSampleR = 1.570796326794897;
				if (inputSampleR < -1.570796326794897) inputSampleR = -1.570796326794897;
				//clip to 1.570796326794897 to reach maximum output
				inputSampleL = sin(inputSampleL);
				inputSampleR = sin(inputSampleR);
				break;
			case 1: //Drive				
				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;
				inputSampleL -= (inputSampleL * (fabs(inputSampleL) * 0.6) * (fabs(inputSampleL) * 0.6));
				inputSampleR -= (inputSampleR * (fabs(inputSampleR) * 0.6) * (fabs(inputSampleR) * 0.6));
				inputSampleL *= 1.5;
				inputSampleR *= 1.5;
				break;
			case 2: //Spiral
				if (inputSampleL > 1.2533141373155) inputSampleL = 1.2533141373155;
				if (inputSampleL < -1.2533141373155) inputSampleL = -1.2533141373155;
				if (inputSampleR > 1.2533141373155) inputSampleR = 1.2533141373155;
				if (inputSampleR < -1.2533141373155) inputSampleR = -1.2533141373155;
				//clip to 1.2533141373155 to reach maximum output
				inputSampleL = sin(inputSampleL * fabs(inputSampleL)) / ((fabs(inputSampleL) == 0.0) ?1:fabs(inputSampleL));
				inputSampleR = sin(inputSampleR * fabs(inputSampleR)) / ((fabs(inputSampleR) == 0.0) ?1:fabs(inputSampleR));
				break;
			case 3: //Mojo
				double mojo; mojo = pow(fabs(inputSampleL),0.25);
				if (mojo > 0.0) inputSampleL = (sin(inputSampleL * mojo * M_PI * 0.5) / mojo) * 0.987654321;
				mojo = pow(fabs(inputSampleR),0.25);
				if (mojo > 0.0) inputSampleR = (sin(inputSampleR * mojo * M_PI * 0.5) / mojo) * 0.987654321;
				//mojo is the one that flattens WAAAAY out very softly before wavefolding				
				break;
			case 4: //Dyno
				double dyno; dyno = pow(fabs(inputSampleL),4);
				if (dyno > 0.0) inputSampleL = (sin(inputSampleL * dyno) / dyno) * 1.1654321;
				dyno = pow(fabs(inputSampleR),4);
				if (dyno > 0.0) inputSampleR = (sin(inputSampleR * dyno) / dyno) * 1.1654321;
				//dyno is the one that tries to raise peak energy				
				break;
		}				
		
		for (int x = 1; x < (stages/2); x++) {
			double temp;
			temp = (inputSampleL+previousOutL[x])*0.5;
			previousOutL[x] = inputSampleL;
			inputSampleL = temp;
			temp = (inputSampleR+previousOutR[x])*0.5;
			previousOutR[x] = inputSampleR;
			inputSampleR = temp;
		}		

		if (output != 1.0) {
			inputSampleL *= output;
			inputSampleR *= output;
		}
		
		if (wet !=1.0) {
			inputSampleL = (inputSampleL * wet) + (drySampleL * (1.0-wet));
			inputSampleR = (inputSampleR * wet) + (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
