#include "header.h"
float Cordic ( float x)	
{
        int bit,i,n=32; // n is the number of iterations.
	float f_b=x,ans; 
	int a[n]; // a[n] is an array used to stroe the binary form of the float number.
	float V[n][2], Cos[n], Sin[n]; // V is a matrix used to store the cos and sin value .
        for ( i=0; i<n; i++)  // creat a matrix Trig to store the basic sine and cosin values
	{
		V[i][0]=cos( pow(0.5,i+1) );  // the first column is the cosin values
		V[i][1]=sin( pow(0.5,i+1) );  // the second column is the sin values
	}

	for ( i=0; i<n; i++)  // change the value to a binary number
	{
	   f_b *= 2.0;
	   bit = (int) f_b; // bit is used to get the integer part of the float number.
	   a[i] = bit;	// a[i] is used to store the binary form for the float number. 
           f_b -= bit;
	}

	if ( a[0]==1)
	{
		Cos[0]=V[0][0];  // initial the value of cos(0.1), where 0.1 is the binary form.
		Sin[0]=V[0][1];  // initial the value of sin(0.1), where 0.1 is the binary form.
	}
	else
	{
		Cos[0]=1;  //initial the value of cos(0.0), where 0.0 is the binary form.
		Sin[0]=0;  //initial the value of sin(0.0), where 0.0 is the binary form.
	}


	
	for  ( i=0; i<n-1; i++)  //using the cordic algorithm, there are total 32 iterations.
	{

	   if (a[i+1]==1)
	   {
	      Cos[i+1]=Cos[i]*V[i+1][0]-Sin[i]*V[i+1][1];	
	      Sin[i+1]=Sin[i]*V[i+1][0]+Cos[i]*V[i+1][1];
	   }
	   else
	   {
	      Cos[i+1]=Cos[i];  
	      Sin[i+1]=Sin[i];
	    }

	}
	ans=Sin[n-1];  
       return ans;
}