[beast/devel: 24/35] BSE: change bse_string_from_double() API, test math to_string functions

[Tim Janik <timj src gnome org>]

commit 6345e8e931e3360ef9529b1dc988e41c277b509a
Author: Tim Janik <timj gnu org>
Date:   Tue May 14 00:50:27 2013 +0200

    BSE: change bse_string_from_double() API, test math to_string functions

 bse/bsemath.cc         |   41 ++++++++++++++++++++++-------------------
 bse/bsemath.hh         |    1 +
 bse/tests/misctests.cc |   24 ++++++++++++++++++++++++
 3 files changed, 47 insertions(+), 19 deletions(-)
---
diff --git a/bse/bsemath.cc b/bse/bsemath.cc
index 3cddc23..e6fbe17 100644
--- a/bse/bsemath.cc
+++ b/bse/bsemath.cc
@@ -6,19 +6,21 @@
 #define RING_BUFFER_LENGTH     (256) // FIXME: simlpy dup strings in the API
 #define        PRINTF_DIGITS           "1270"
 #define        FLOAT_STRING_SIZE       (2048)
+
 /* --- functions --- */
-static inline char*
-pretty_print_double (char  *str,
-                    double d)
+std::string
+bse_string_from_double (long double value)
 {
-  char *s= str;
-  sprintf (s, "%." PRINTF_DIGITS "f", d);
+  std::string str;
+  str.resize (FLOAT_STRING_SIZE, 0);
+  char *s = &str[0];
+  sprintf (s, "%." PRINTF_DIGITS "Lf", value);
   while (*s)
     s++;
-  while (s[-1] == '0' && s[-2] != '.')
+  while (s > &str[2] && s[-1] == '0' && s[-2] != '.')
     s--;
   *s = 0;
-  return s;
+  return std::string (str.c_str());
 }
 
 char*
@@ -40,10 +42,11 @@ bse_complex_list (uint         n_points,
       *s = 0;
       if (indent)
        strcat (s, indent);
-      while (*s) s++;
-      s = pretty_print_double (s, points[i].re);
+      while (*s)
+        s++;
+      *s = 0; strcat (s, bse_string_from_double (points[i].re).c_str()); s += strlen (s);
       *s++ = ' ';
-      s = pretty_print_double (s, points[i].im);
+      *s = 0; strcat (s, bse_string_from_double (points[i].im).c_str()); s += strlen (s);
       *s++ = '\n';
     }
   *s++ = 0;
@@ -63,10 +66,10 @@ bse_complex_str (BseComplex c)
     g_free (rbuffer[rbi]);
   s = tbuffer;
   *s++ = '{';
-  s = pretty_print_double (s, c.re);
+  *s = 0; strcat (s, bse_string_from_double (c.re).c_str()); s += strlen (s);
   *s++ = ',';
   *s++ = ' ';
-  s = pretty_print_double (s, c.im);
+  *s = 0; strcat (s, bse_string_from_double (c.im).c_str()); s += strlen (s);
   *s++ = '}';
   *s++ = 0;
   rbuffer[rbi] = g_strdup (tbuffer);
@@ -90,14 +93,14 @@ bse_poly_str (uint         degree,
     g_free (rbuffer[rbi]);
   s = tbuffer;
   *s++ = '(';
-  s = pretty_print_double (s, a[0]);
+  *s = 0; strcat (s, bse_string_from_double (a[0]).c_str()); s += strlen (s);
   for (i = 1; i <= degree; i++)
     {
       *s++ = '+';
       *s = 0; strcat (s, var); while (*s) s++;
       *s++ = '*';
       *s++ = '(';
-      s = pretty_print_double (s, a[i]);
+      *s = 0; strcat (s, bse_string_from_double (a[i]).c_str()); s += strlen (s);
     }
   while (i--)
     *s++ = ')';
@@ -125,7 +128,7 @@ bse_poly_str1 (uint         degree,
   *s++ = '(';
   if (a[0] != 0.0)
     {
-      s = pretty_print_double (s, a[0]);
+      *s = 0; strcat (s, bse_string_from_double (a[0]).c_str()); s += strlen (s);
       need_plus = 1;
     }
   for (i = 1; i <= degree; i++)
@@ -140,7 +143,7 @@ bse_poly_str1 (uint         degree,
        }
       if (a[i] != 1.0)
        {
-         s = pretty_print_double (s, a[i]);
+          *s = 0; strcat (s, bse_string_from_double (a[i]).c_str()); s += strlen (s);
          *s++ = '*';
        }
       *s = 0;
@@ -183,9 +186,9 @@ bse_float_gnuplot (const char    *file_name,
   uint i;
   for (i = 0; i < n_ypoints; i++)
     {
-      char xstr[FLOAT_STRING_SIZE], ystr[FLOAT_STRING_SIZE];
-      pretty_print_double (xstr, xstart + i * xstep);
-      pretty_print_double (ystr, ypoints[i]);
+      char xbuf[FLOAT_STRING_SIZE], *xstr = xbuf, ybuf[FLOAT_STRING_SIZE], *ystr = ybuf;
+      *xstr = 0; strcat (xstr, bse_string_from_double (xstart + i * xstep).c_str()); xstr += strlen (xstr);
+      *ystr = 0; strcat (ystr, bse_string_from_double (ypoints[i]).c_str()); ystr += strlen (ystr);
       fprintf (fout, "%s %s\n", xstr, ystr);
     }
   fclose (fout);
diff --git a/bse/bsemath.hh b/bse/bsemath.hh
index f37d4b3..92e2eec 100644
--- a/bse/bsemath.hh
+++ b/bse/bsemath.hh
@@ -85,6 +85,7 @@ char*                    bse_complex_list       (uint           n_points,
 void                     bse_complex_gnuplot    (const char    *file_name,
                                                  uint           n_points,
                                                  BseComplex    *points);
+std::string              bse_string_from_double (long double    value);
 
 /* --- polynomials --- */
 /* example, degree=2: 5+2x+7x^2 => a[0..degree] = { 5, 2, 7 } */
diff --git a/bse/tests/misctests.cc b/bse/tests/misctests.cc
index cccaadf..95a6c21 100644
--- a/bse/tests/misctests.cc
+++ b/bse/tests/misctests.cc
@@ -105,11 +105,35 @@ check_freq_vs_notes (BseMusicalTuningType musical_tuning)
     }
   TDONE();
 }
+
+static void
+test_math_bits ()
+{
+  TCMP (bse_string_from_double (-1.0), ==, "-1.0");
+  TCMP (bse_string_from_double (0.0), ==, "0.0");
+  TCMP (bse_string_from_double (1000000000000000.75000000000000), ==, "1000000000000000.75");
+  BseComplex c[] = { { 0, 0 }, { -1, +1 }, { +2, -3 } };
+  const std::string c0 = bse_complex_str (c[0]);
+  TCMP (c0, ==, "{0.0, 0.0}");
+  const std::string c1 = bse_complex_str (c[1]);
+  TCMP (c1, ==, "{-1.0, 1.0}");
+  const std::string c2 = bse_complex_str (c[2]);
+  TCMP (c2, ==, "{2.0, -3.0}");
+  const std::string complex_list = bse_complex_list (RAPICORN_ARRAY_SIZE (c), c, "");
+  TCMP (complex_list, ==, "0.0 0.0\n-1.0 1.0\n2.0 -3.0\n");
+  double a[] = { 0, -1, +2, -3, +7.75, -1000000000000000.75 };
+  const std::string poly1 = bse_poly_str (RAPICORN_ARRAY_SIZE (a) - 1, a, "x");
+  TCMP (poly1, ==, "(0.0+x*(-1.0+x*(2.0+x*(-3.0+x*(7.75+x*(-1000000000000000.75))))))");
+  const std::string poly2 = bse_poly_str1 (RAPICORN_ARRAY_SIZE (a) - 1, a, "y");
+  TCMP (poly2, ==, "(-1.0*y + 2.0*y**2 + -3.0*y**3 + 7.75*y**4 + -1000000000000000.75*y**5)");
+}
+
 int
 main (gint   argc,
       gchar *argv[])
 {
   bse_init_test (&argc, argv);
+  test_math_bits();
   check_cent_tune();
   check_cent_tune_fast();
   check_equal_tempered_tuning();