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

#include "curve.h"

#ifdef SHR3D_SFX_CORE_AIRWINDOWS

namespace airwinconsolidated::curve {

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

    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;
		
		inputSampleL *= 0.5;
		inputSampleR *= 0.5;
		
		if (gain < 0.0078125) gain = 0.0078125; if (gain > 1.0) gain = 1.0;
		//gain of 1,0 gives you a super-clean one, gain of 2 is obviously compressing
		//smaller number is maximum clamping, if too small it'll take a while to bounce back
		inputSampleL *= gain; inputSampleR *= gain;
		
		gain += sin((fabs(inputSampleL*4)>1)?4:fabs(inputSampleL*4))*pow(inputSampleL,4);
		gain += sin((fabs(inputSampleR*4)>1)?4:fabs(inputSampleR*4))*pow(inputSampleR,4);
		//4.71239 radians sined will turn to -1 which is the maximum gain reduction speed
		
		inputSampleL *= 2.0;
		inputSampleR *= 2.0;
		
		//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
