#include "lookup_math.h"
#include <math.h>

/* longest local memory table for Zynq 7010 */
#define SIN_TABLE_LEN 0x10000

int firstrun = 1;
int lastlen  = 0;

void init_sin_table(din1_t sin_table[256], int len)
{
   int i;
   for (i = 0; i < len; i++) {
      float real_val = sinf(M_PI * (float)(i - len/2) / len);
      sin_table[i] = (din1_t)(32768.0 * real_val);
   }
}

dout_t lookup_math(din1_t inval, din2_t idx)
{
  #pragma HLS INTERFACE s_axilite register port=inval
  #pragma HLS INTERFACE s_axilite register port=idx
  #pragma HLS INTERFACE s_axilite register port=return

   short sin_table[SIN_TABLE_LEN], a;
   if (firstrun == 1) {
      init_sin_table(sin_table, 256);
      firstrun = 0; lastlen = 256;
   }
   if (lastlen == 256) {
	   init_sin_table(sin_table, SIN_TABLE_LEN);
	   lastlen = SIN_TABLE_LEN;
   }
   return  (int)sin_table[inval];
}