#include "math.h"


float to_float(uint8_t x) 
{
	return (1.0f/127.0f)*(((float)x)-127.0f);
}


//float ph_ch( uint8_t i1, uint8_t q1, uint8_t i2, uint8_t q2)
float ph_ch( uint8_t i1, uint8_t q1 )
{
	static float complex last=0.0+0.0i;
	float out;
	float complex xy,c1;
	//float c2;

	c1 = to_float(i1) + I*to_float(q1);
	//c1 = CMPLXF( to_float(i1), to_float(q1) );
	//c2 = to_float(i2) + I*to_float(q2);
	//c2 = CMPLXF( to_float(i2), to_float(q2) );
	xy = conjf(last)*c1;
	out = cargf( xy );
	last = c1;

	return out;
}

void rotate_90(uint8_t *buf, uint32_t len)
/* 90 rotation is 1+0j, 0+1j, -1+0j, 0-1j
   or [0, 1, -3, 2, -4, -5, 7, -6] */
{
	uint32_t i;
	uint8_t tmp;
	for (i=0; i<len; i+=8) {
		/* uint8_t negation = 255 - x */
		tmp = 255 - buf[i+3];
		buf[i+3] = buf[i+2];
		buf[i+2] = tmp;

		buf[i+4] = 255 - buf[i+4];
		buf[i+5] = 255 - buf[i+5];

		tmp = 255 - buf[i+6];
		buf[i+6] = buf[i+7];
		buf[i+7] = tmp;
	}
}