#include <pal_master.hch>
#include <stdlib.hch>
#include "weights256.hch"
#include "config.hch"
#include "debug.hch"
#include "xilinxmult.hch"

#define      	PERFORM_FFT_CALCULATION 1
#define		USE_UNSIGNED_AUDIO 0
#define      	HARDWARE_MULTIPLY 1
#define		PRINT_DEBUG 0
/* Define two multi-port RAMs for FFT calculation; one for real and one for imaginary values
 * Extra block RAM settings are defined to make sure read and write actions can be performed
 * within one clock-cycle.
 * Left out extra settings on new board the clock changes TODO !!!!
 */
mpram
{
  ram signed 24 rwrite[256];
  rom signed 24 read[256];
} real with {block = "BlockRAM"/*, westart=2.5, welength=1, rclkpos={1.5}, wclkpos={3}, clkpulselen=0.5*/};

mpram 
{
  ram signed 24 rwrite[256];
  rom signed 24 read[256];
} imaginary with {block = "BlockRAM"/*, westart=2.5, welength=1, rclkpos={1.5}, wclkpos={3}, clkpulselen=0.5*/};

// multiplication factors for equalizer function
ram signed 7 eq_settings[16] = {0,2,4,7,10,13,16,19,22,26,30,35,41,48,55,63};


/****************************************************************
* Function:    multiply                                         *
*                                                               *
* Arguments                                                     *
*   x,y        signed variables                                 *
*                                                               *
* Description                                                   *
*   Just a multiplier. But by doing this in a function the      *
*   FPGA space needed is reduced.                               *
*                                                               *
* Return Values                                                 *
*   The result after multiplication                             *
****************************************************************/
macro proc multiply(result, op_a, op_b)
{
#if HARDWARE_MULTIPLY
	xilinxmult(result, adjs(op_a,18), adjs(op_b,18));
#else
	macro expr mul_width  = (width(op_a) + width(op_b));
	result = adjs(op_a, mul_width) * adjs(op_b, mul_width);
#endif	
/*	signed result;
  	
	fixed_mul(result,x,y);
  	return result;*/
}
/*macro proc multiply(result, x,y) 
{
#if HARDWARE_MULTIPLY	
	xilinxmult(result, adjs(x,18), adjs(y,18));
#else	
	result = ((adjs(x,36))*(adjs(y,36)));
#endif
  
}
*/



/*******************************************************************
* Function:    calculate_fft                                       *
*                                                                  *
* Arguments                                                        *
*   select_inverse	Boolean that indicates FFT or iFFT calculation *
*                                                                  *
* Description                                                      *
*   This routine performs the Fast Fourier Transform for		   *
*   calculation of the frequency spectrum					       *
*                                                                  *
*******************************************************************/
void calculate_fft(unsigned 1 select_inverse)
{
  unsigned 4 level;
  unsigned 8 point1,point2,j,f,k;
  unsigned 9 e,i;
  signed 16 weight1,weight2;
  signed 24 p,q,r,t;
  signed a,b;

  macro expr rescale (x) = (x[35] @ x[28:14]);

  for(level=1;level<=NUMBER_OF_COLUMNS;level++) // count all the columns
  {
    	e=1<<(NUMBER_OF_COLUMNS-level+1); // number of points in each block in this column
    	f=(e>>1)<-8; 					  // number of butterflies in each block in this column

    	for(j=1;j<=f;j++) 	// count all the butterflies in each block
    	{
		par
		{
      			// Weight factors for real (the same for FFT and iFFT)
	  		weight1 = weight_re[((j-1)<<(level-1))<-7]; 

			
			// Weight factors for imaginary (opposite for FFT and iFFT)
	  		weight2 = (!select_inverse) ? (weight_im[((j-1)<<(level-1))<-7]) : -(weight_im[((j-1)<<(level-1))<-7]); 

			/* ORIGINAL CODE BELOW, MODIFIED BECAUSE OF MISMATCHING OUTPUT WITH BORLAND TESTAPP
			weight2 = (!select_inverse) ? -(weight_im[((j-1)<<(level-1))<-7]) : weight_im[((j-1)<<(level-1))<-7]; 
			*/
			
			

			for(i=0@j;i<=NUMBER_OF_POINTS;i+=e)   // count all the blocks in this column
			{	// Butterfly calculation
        			par
				{
					point1 = ((i<-8)-1);
	      				point2 = (((i<-8)+f)-1);
	    			}
				
				par
				{
					p=real.read[point1]+real.rwrite[point2];
		  			q=imaginary.read[point1]+imaginary.rwrite[point2];
				}
				
				par
				{
		      			r=real.read[point1]-real.rwrite[point2];
					t=imaginary.read[point1]-imaginary.rwrite[point2];
				}		

				multiply(a,r,weight1);
				multiply(b,t,weight2);

       		        	par
 				{
        	  			real.rwrite[point2] = ((a-b)>>FRACBITS)<-24;
          				imaginary.rwrite[point1] = q;
    				}

				multiply(a,t,weight1);
				multiply(b,r,weight2);

				par
				{	
					real.rwrite[point1] = p;
		  			imaginary.rwrite[point2] = ((a+b)>>FRACBITS)<-24;
		  		}

		  	}
		}
	}
  }

  j=1;
  for(i=1;i<NUMBER_OF_POINTS;i++)
  {
  	if(i<(0@j))
   	{
   		par
		{
			point1=j-1;
   			point2=(i-1)<-8;
		}
		/*
		  COPYING ARRAY VALUES FROM ONE PLACE TO ANOTHER IN THE ARRAT MUST BE DONE IN 
		  2 STEPS. FIRSTLY THE VALUES ARE COPIED TO SEPARATE VARIABLES AFTER THAT THEY
		  ARE COPIED BACK TO THEIR NEW POSITION IN THE ARRAY. THIS MUST BE DONE TO 
		  PREVENT TIMING ISSUES FROM OCCURING.
		*/
   		par
		{
			p = real.read[point1];
   			q = imaginary.read[point1];
		}
		par
		{
			r = real.read[point2];
   			t = imaginary.read[point2];
		}
		par
		{
			real.rwrite[point1] = r;   	
   			imaginary.rwrite[point1] = t;
		}
  		par
		{
			real.rwrite[point2] = p;
   			imaginary.rwrite[point2] = q;
		}
   	}

  	k = NUMBER_OF_POINTS>>1;


  	while(k<j)
   	{
   		j = j-k;
   		k = k>>1;
   	}

  	j+=k;
  }

}

/********************************************************************/

void perform_fft(signed 16 *pcm_audio)
{
  	unsigned 8 k;
	signed 24 sample;
#if USE_UNSIGNED_AUDIO
	unsigned 24 utemp;
	signed 24 stemp;
#endif
    	
	//initialize variables for the copying pipeline
	k=0;
	sample = adjs(pcm_audio[k],24);
	// copy audio data to real-array before starting FFT calculation
	// and set imaginary values to zero
	do
	{
#if USE_UNSIGNED_AUDIO
		stemp = adjs(pcm_audio[k],24);
		stemp >>= 1;
		utemp = 0@((unsigned)((stemp + 32768)<-16));
	      	real.rwrite[k] = (signed)(utemp);
#else
		//Copying the array values has been pipelined to prevent parallel access to the
		//pcm_audio array. This copying procedure must be finished before another 
		//sample is read from the audio input. The time available for this loop is 
		//determined by the sampling rate of 44,1 Khz
		par
		{
			//COPYING NEEDS TO BE DONE IN 2 STEPS, BECAUSE THE VALUE THAT NEEDS TO WRITTEN
			//TO THE REAL-RAM NEEDS TO BE AVAILABLE ON THE START OFF THE CLOCKCYCLE.
			sample = adjs(pcm_audio[k+1],24);
			real.rwrite[k] = sample;
      			imaginary.rwrite[k] = 0;
			k++;
		}
		
#endif
    	}  while (k);

	

#if PERFORM_FFT_CALCULATION
	calculate_fft(0);
#endif


}

/********************************************************************/

void perform_ifft(signed 16 *modified_audio/*, unsigned 6 *ifft_info*/)
{
  	unsigned 6 k;
  	signed 24 p;

#if PERFORM_FFT_CALCULATION	
	calculate_fft(1);
#endif

    	k=0;
#if PRINT_DEBUG
	do
	{
		print_string("real[");
		print_hex_value(0@k);
		print_string("]: ");
		print_hex_value((unsigned)real.read[k]);
		print_string(" imaginary[");
		print_hex_value(0@k);
		print_string("]: ");
		print_hex_value((unsigned)imaginary.read[k]);
		print_eol();
		k++;
	}
	while(k!=0);
#endif
//initialize variables for the copying pipeline
#if PERFORM_FFT_CALCULATION	
		p = (real.read[(0@k)+95] >> NUMBER_OF_COLUMNS);
#else
		p = (real.read[(0@k)+95]);
#endif

	do
	{
		//Copying the array values has been pipelined to prevent parallel access to the
		//pcm_audio array. This copying procedure must be finished before another 
		//sample is read from the audio input. The time available for this loop is 
		//determined by the sampling rate of 44,1 Khz
	   	par
		{
#if PERFORM_FFT_CALCULATION
			// divide samples by number of points
			p = (real.read[(0@k+1)+95] >> NUMBER_OF_COLUMNS);
#else	
			p = (real.read[(0@k+1)+95]);
#endif
#if USE_UNSIGNED_AUDIO
			p -= 32768;
			p <<= 1;
#endif
      			modified_audio[k] = (p  <-16);
			//ifft_info[k] = (unsigned)(p[15:10]); 		
			k++;
		}
    	} while(k);
}

/********************************************************************/
void equalize_audio(unsigned 4 *eq_level, unsigned 7 *fft_info)
{
#if 0
  signed 24 p,q;
  signed 16 a;
  unsigned 8 i, mirror_i, bit, m, n;
  unsigned 7 old_value;
  unsigned 9 tmp;
  
  //macro expr equalize_bar = adjs(q,24)-adjs(a,24);
  
  macro proc equalize_bar()
  {
  	 signed result;
 	 multiply(result, q,a);
	 return result[29:6];
  } 

  p = real.read[0] - DC_COMPONENT; // remove DC component for calculations
  real.rwrite[0] = p;
//  imaginary.rwrite[0] = 0; 				   		// remove DC component 

  
  for(i=0;i<=NUMBER_OF_FREQUENCIES;i++)	  
  {  
	// set multiplication factor (0..64) for current frequency bar
	a = adjs(eq_settings[eq_level[i<-7]],16);

	// multiply frequency with this factor and divide by 64 (drop 6 LSB's)
	q = real.read[i];
	p = equalize_bar;
	real.rwrite[i] = p;

    	q = imaginary.read[i];
	p = equalize_bar;
	imaginary.rwrite[i] = p;

	// the upper part(128..255) of the spectrum is mirrored to the lower part; 
	// these values need to be adjusted too
	if ((i<-7)!=0) // if not in DC component bar
	{
		mirror_i = (NUMBER_OF_POINTS-1)-i+1;
		q = real.read[mirror_i];
		p = equalize_bar;
		real.rwrite[mirror_i] = p;

		q = imaginary.read[mirror_i];
		p = equalize_bar;
		imaginary.rwrite[mirror_i] = p;
	}
  }
  
  //write data to fft_info for display purposes
  for(i=0;i<NUMBER_OF_FREQUENCIES;i++)
  {
   	p = real.read[i];
    	q = imaginary.read[i];

    	if (p[23] == 1) p = -p; else delay;
	if (q[23] == 1) q = -q; else delay;
	p = (p<q) ? q : p; // This is done to get the best visual frequency result
	 
	if (display_log)
	{

		bit=126;
		while ((p[21] == 0) && (bit != 0))
			par
			{
				p = p<<1;
				bit = bit - 18;
			}
		old_value = fft_info[i<-7];
		tmp = ((0@old_value) + (0@bit))>>1;
		fft_info[i<-7] = (old_value <= (tmp<-7)) ? (tmp<-7) : old_value-1;
	} 
	else 
	{
		old_value = fft_info[i<-7];
		fft_info[i<-7] = (old_value<=(unsigned)(p[21:15])) ? (unsigned)(p[21:15]) : old_value-1;
	}
  }

  // add DC component again before inverse FFT calculation is performed
  p = real.read[0] + DC_COMPONENT; 
  real.rwrite[0] = p;
#endif
}