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

#include "Shape.h"

#ifdef SHR3D_SFX_CORE_AIRWINDOWS

namespace airwinconsolidated::Shape {

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

	double shape = -((A*2.0)-1.0);
	double gainstage = fabs(shape)+0.01; //no divide by zero
	double offset = (B*2.0)-1.0;
	double postOffset = 0.0;
	if (shape > 0) {
		gainstage += 0.99;
		postOffset = sin(offset);
	}
	if (shape < 0) postOffset = asin(offset);
	double cutoff = 25000.0 / getSampleRate();
	if (cutoff > 0.49) cutoff = 0.49; //don't crash if run at 44.1k
	fixA[fix_freq] = cutoff;
	fixA[fix_reso] = 0.70710678; //butterworth Q
	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;
	fixA[fix_sL1] = 0.0;
	fixA[fix_sL2] = 0.0;
	fixA[fix_sR1] = 0.0;
	fixA[fix_sR2] = 0.0;
	//define filters here: on VST you can't define them in reset 'cos getSampleRate isn't returning good information yet
	
    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 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
		
		inputSampleL *= gainstage;
		inputSampleL += offset;
		if (inputSampleL > 1.0) inputSampleL = 1.0;
		if (inputSampleL < -1.0) inputSampleL = -1.0;
		if (shape > 0) inputSampleL = sin(inputSampleL);
		if (shape < 0) inputSampleL = asin(inputSampleL);
		inputSampleL -= postOffset;
		inputSampleL = ((inputSampleL/gainstage)*fabs(shape))+(drySampleL*(1.0-fabs(shape)));
		
		
		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
		
		inputSampleR *= gainstage;
		inputSampleR += offset;
		if (inputSampleR > 1.0) inputSampleR = 1.0;
		if (inputSampleR < -1.0) inputSampleR = -1.0;
		if (shape > 0) inputSampleR = sin(inputSampleR);
		if (shape < 0) inputSampleR = asin(inputSampleR);
		inputSampleR -= postOffset;
		inputSampleR = ((inputSampleR/gainstage)*fabs(shape))+(drySampleR*(1.0-fabs(shape)));
		
		//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
