libs/ardour/ardour/latent.h

   1 /*
   2     Copyright (C) 1999-2009 Paul Davis
   3
   4     This program is free software; you can redistribute it and/or modify
   5     it under the terms of the GNU General Public License as published by
   6     the Free Software Foundation; either version 2 of the License, or
   7     (at your option) any later version.
   8
   9     This program is distributed in the hope that it will be useful,
  10     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12     GNU General Public License for more details.
  13
  14     You should have received a copy of the GNU General Public License
  15     along with this program; if not, write to the Free Software
  16     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17
  18 */
  19
  20 #ifndef __ardour_latent_h__
  21 #define __ardour_latent_h__
  22
  23 #include "ardour/types.h"
  24
  25 namespace ARDOUR {
  26
  27 class Latent {
  28   public:
  29         Latent() : _user_latency (0) {}
  30         virtual ~Latent() {}
  31
  32         virtual framecnt_t signal_latency() const = 0;
  33         framecnt_t user_latency () const { return _user_latency; }
  34
  35         framecnt_t effective_latency() const {
  36                 if (_user_latency) {
  37                         return _user_latency;
  38                 } else {
  39                         return signal_latency ();
  40                 }
  41         }
  42
  43         virtual void set_user_latency (framecnt_t val) { _user_latency = val; }
  44
  45   protected:
  46         framecnt_t           _user_latency;
  47 };
  48
  49 }
  50
  51 #endif /* __ardour_latent_h__*/