From 9477dbe667f250ecd23f8fc0d56b942191526421 Mon Sep 17 00:00:00 2001
From: Franciszek Malinka <franciszek.malinka@gmail.com>
Date: Thu, 25 Feb 2021 14:42:55 +0100
Subject: Stare semestry, niepoukladane

---
 Semestr 3/anm/cordic/cordic.cpp | 189 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 189 insertions(+)
 create mode 100644 Semestr 3/anm/cordic/cordic.cpp

(limited to 'Semestr 3/anm/cordic/cordic.cpp')

diff --git a/Semestr 3/anm/cordic/cordic.cpp b/Semestr 3/anm/cordic/cordic.cpp
new file mode 100644
index 0000000..b0dfd39
--- /dev/null
+++ b/Semestr 3/anm/cordic/cordic.cpp	
@@ -0,0 +1,189 @@
+#include <stdio.h>
+#include <math.h>
+//#define M_PI 3.1415926536897932384626
+int main(int argc, char **argv)
+{
+  FILE *f;
+  char tname[50], cname[10];
+  int n, n2, mp2, niter, bits, t;
+  double F, A, mul, tmul; // CORDIC gain, convergence angle, multiplication factor
+  printf("0)circular, 1)linear, 2)hyperbolic? ");
+  scanf("%d", &t);
+  switch (t)
+  {
+  case 0:
+    sprintf(cname, "%s", "");
+    break;
+  case 1:
+    sprintf(cname, "%s", "_LIN");
+    break;
+  case 2:
+    sprintf(cname, "%s", "_HYPER");
+    break;
+  }
+  sprintf(tname, "CORDICtable%s.c", cname);
+  if (NULL == (f = fopen(tname, "wt")))
+  {
+    printf("cannot write to %s\n", tname);
+    return 0;
+  }
+
+  printf("number of bits for mantissa (e.g. 30)? ");
+  scanf("%d", &bits);
+  printf("0) mul factor is 2^n (easier output scaling), or\n"
+         "1) 2pi is 2^n (easier implementation)\n ? ");
+  scanf("%d", &mp2);
+  printf("suggested multiplication factor ");
+  if (mp2 == 0)
+  {
+    tmul = (double)(1 << (bits - 3));
+    printf("2^%d = %f\n", bits - 3, tmul);
+  }
+  else
+  {
+    tmul = (double)(1 << (bits - 2)) / M_PI;
+    printf("2^%d/pi = %f\n", bits - 2, tmul);
+  }
+  printf("multiplication factor (0 for suggested)? ");
+  scanf("%lf", &mul);
+  if (mul < 0.1)
+  {
+    mul = tmul;
+    printf("%f\n", mul);
+  }
+  else
+    mp2 = -1; // custom mul factor
+  switch (t)
+  {
+  case 0:
+    for (n = 0; n < bits; n++)
+      if ((int)round(atan(pow(2.0, (double)(-n))) * mul) == 0)
+        break;
+    break;
+  case 1:
+    for (n = 0; n < bits; n++)
+      if ((int)round((pow(2.0, (double)(-n))) * mul) == 0)
+        break;
+    break;
+  case 2:
+    for (n = 1, n2 = 4; n < bits;)
+    {
+      if ((int)round(atanh(pow(2.0, (double)(-n))) * mul) == 0)
+        break;
+      if (n == n2)
+        n2 = 3 * n + 1;
+      else
+        n++;
+    }
+    break;
+  }
+  printf("iterations (up to %d)? ", n);
+  scanf("%d", &niter);
+
+  F = 1.0;
+  A = 0.0;
+  switch (t)
+  {
+  case 0:
+    for (n = 0; n < niter; n++)
+    {
+      F = F * sqrt(1 + pow(2.0, -2.0 * n));
+      A += atan(pow(2.0, (double)(-n)));
+    }
+    break;
+  case 1:
+    for (n = 0; n < niter; n++)
+    {
+      F = F * sqrt(1);
+      A += (pow(2.0, (double)(-n)));
+    }
+    break;
+  case 2:
+    for (n = 1, n2 = 4; n < niter;)
+    {
+      F = F * sqrt(1 - pow(2.0, -2.0 * n));
+      A += atanh(pow(2.0, (double)(-n)));
+      if (n == n2)
+        n2 = 3 * n + 1;
+      else
+        n++;
+    }
+    break;
+  }
+
+  fprintf(f, "//CORDIC%s, %d bits, %d iterations\n", cname, bits, niter);
+  fprintf(f, "// 1.0 = %f multiplication factor\n", mul);
+  switch (t)
+  {
+  case 0:
+    fprintf(f, "// A = %lf convergence angle "
+               "(limit is 1.7432866 = 99.9deg)\n",
+            A);
+    fprintf(f, "// F = %lf gain (limit is 1.64676025812107)\n", F);
+    fprintf(f, "// 1/F = %lf inverse gain (limit is 0.607252935008881)\n", 1.0 / F);
+    break;
+  case 1:
+    fprintf(f, "// A = %lf convergence angle (limit is 2)\n", A);
+    fprintf(f, "// F = %lf gain (limit is 1.0)\n", F);
+    fprintf(f, "// 1/F = %lf inverse gain (limit is 1.0)\n", 1.0 / F);
+    break;
+  case 2:
+    fprintf(f, "// A = %lf convergence angle "
+               "(limit is 1.1181730 = 64.0deg)\n",
+            A);
+    fprintf(f, "// F = %lf gain (limit is 0.82978162013890)\n", F);
+    fprintf(f, "// 1/F = %lf inverse gain (limit is 1.20513635844646)\n", 1.0 / F);
+    break;
+  }
+  fprintf(f, "// pi = %lf (3.1415926536897932384626)\n", M_PI);
+  fprintf(f, "\n");
+  fprintf(f, "#define CORDIC%s_A %f // CORDIC convergence angle A\n", cname, A);
+  fprintf(f, "#define CORDIC%s_F 0x%08X // CORDIC gain F\n",
+          cname, (int)round(mul * F));
+  fprintf(f, "#define CORDIC%s_1F 0x%08X // CORDIC inverse gain 1/F\n",
+          cname, (int)round(mul / F));
+  fprintf(f, "#define CORDIC%s_HALFPI 0x%08X\n", cname, (int)round(mul * (M_PI / 2.0)));
+  fprintf(f, "#define CORDIC%s_PI 0x%08X\n", cname, (int)round(mul * (M_PI)));
+  fprintf(f, "#define CORDIC%s_TWOPI 0x%08X\n", cname, (int)round(mul * (2.0 * M_PI)));
+  fprintf(f, "#define CORDIC%s_MUL %f // CORDIC multiplication factor M", cname, mul);
+  switch (mp2)
+  {
+  case 0:
+    fprintf(f, " = 2^%d\n", bits - 3);
+    break;
+  case 1:
+    fprintf(f, " = 2^%d/pi\n", bits - 2);
+    break;
+  default:
+    fprintf(f, "\n");
+    break;
+  }
+  fprintf(f, "#define CORDIC%s_MAXITER %d\n\n", cname, niter);
+  fprintf(f, "int CORDIC%s_ZTBL[] = {", cname);
+  for (n = 0; n < niter; n++)
+  {
+    if ((n % 8) == 0)
+      fprintf(f, "\n ");
+    switch (t)
+    {
+    case 0:
+      fprintf(f, "0x%08X", (int)round(atan(pow(2.0, (double)(-n))) * mul));
+      break;
+    case 1:
+      fprintf(f, "0x%08X", (int)round((pow(2.0, (double)(-n))) * mul));
+      break;
+    case 2:
+      n = n == 0 ? 1 : n;
+      fprintf(f, "0x%08X", (int)round(atanh(pow(2.0, (double)(-n))) * mul));
+      break;
+    }
+    if (n < (niter - 1))
+      fprintf(f, ", ");
+    else
+      fprintf(f, " ");
+  }
+  fprintf(f, "};\n\n");
+  fclose(f);
+  printf("table written to %s\n", tname);
+  return 0;
+}
-- 
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