Allow setting filter range from command line (#47)

doc/en/sidplayfp.pod

@@ -186,7 +186,15 @@ This is the default.
 
 =item B<--fcurve=>I<< <num>|auto >>
 
-Controls the filter curve in the ReSIDfp mulation.
+Controls the filter curve in the ReSIDfp emulation.
+Ranges from 0.0 (light) to 1.0 (dark), the default
+value is 0.5.  If set to auto it will choose a
+predefined value for 6581 depending on the tune author.
+
+=item B<--frange=>I<< <num>|auto >>
+
+If available controls the filter range for the 6581
+in the ReSIDfp emulation.
 Ranges from 0.0 (light) to 1.0 (dark), the default
 value is 0.5.  If set to auto it will choose a
 predefined value for 6581 depending on the tune author.

src/args.cpp

@@ -1,7 +1,7 @@
 /*
  * This file is part of sidplayfp, a console SID player.
  *
- * Copyright 2011-2023 Leandro Nini
+ * Copyright 2011-2024 Leandro Nini
  * Copyright 2000-2001 Simon White
  *
  * This program is free software; you can redistribute it and/or modify
@@ -401,6 +401,19 @@ int ConsolePlayer::args(int argc, const char *argv[])
                     m_fcurve = atof(&argv[i][9]);
                 }
             }
+#ifdef FEAT_FILTER_RANGE
+            else if (strncmp (&argv[i][1], "-frange=", 8) == 0)
+            {
+                if (strncmp (&argv[i][9], "auto", 4) == 0)
+                {
+                    m_autofilter = true;
+                }
+                else
+                {
+                    m_frange = atof(&argv[i][9]);
+                }
+            }
+#endif
             // File format conversions
             else if (argv[i][1] == 'w')
             {
@@ -676,7 +689,9 @@ void ConsolePlayer::displayArgs (const char *arg)
         << " -r[i|r][f]   set resampling method (default: resample interpolate)" << endl
         << "              Use 'f' to enable fast resampling (only for reSID)" << endl
         << " --fcurve=<num>|auto Controls the filter curve in the ReSIDfp emulation (0.0 to 1.0, default: 0.5)" << endl
-
+#ifdef FEAT_FILTER_RANGE
+        << " --frange=<num>|auto Controls the filter range in the ReSIDfp emulation (0.0 to 1.0, default: 0.5)" << endl
+#endif
         << " -w[name]     create wav file (default: <datafile>[n].wav)" << endl
         << " --au[name]   create au file (default: <datafile>[n].au)" << endl
         << " --info       add metadata to wav file" << endl;

src/player.cpp

@@ -331,6 +331,7 @@ ConsolePlayer::ConsolePlayer (const char * const name) :
     m_outfile(nullptr),
     m_filename(""),
     m_fcurve(-1.0),
+    m_frange(-1.0),
     m_quietLevel(0),
     songlengthDB(sldb_t::NONE),
     m_cpudebug(false),
@@ -622,6 +623,11 @@ bool ConsolePlayer::createSidEmu (SIDEMUS emu, const SidTuneInfo *tuneInfo)
                     cerr << "Recommended filter range: " << frange << endl;
             }
 
+            if (m_frange >= 0.0)
+            {
+                frange = m_frange;
+            }
+
             if ((frange < 0.0) || (frange > 1.0))
             {
                 cerr << "Invalid 6581 filter range: " << frange << endl;

src/player.h

@@ -154,6 +154,9 @@ class ConsolePlayer
     SidDatabase        m_database;
 
     double             m_fcurve;
+#ifdef FEAT_FILTER_RANGE
+    double             m_frange;
+#endif
 
 #ifdef FEAT_CW_STRENGTH
     SidConfig::sid_cw_t m_combinedWaveformsStrength;