X-Git-Url: https://main.carlh.net/gitweb/?a=blobdiff_plain;f=libs%2Fevoral%2Fevoral%2FTimeConverter.hpp;h=6c02507c174aaf2b52544104b3be038e9dca3d96;hb=22fd92f97c5ff2bb1890a3b88085bed5c035498e;hp=5fcfbfcf2b79e253b8eb575b04b4256ccc6fafc9;hpb=8855b1643c6e18f567bafb975478fa3bbaf56270;p=ardour.git

diff --git a/libs/evoral/evoral/TimeConverter.hpp b/libs/evoral/evoral/TimeConverter.hpp
index 5fcfbfcf2b..6c02507c17 100644
--- a/libs/evoral/evoral/TimeConverter.hpp
+++ b/libs/evoral/evoral/TimeConverter.hpp
@@ -19,19 +19,27 @@
 #ifndef EVORAL_TIME_CONVERTER_HPP
 #define EVORAL_TIME_CONVERTER_HPP
 
+#include "evoral/visibility.h"
+
 namespace Evoral {
 
 /** A bidirectional converter between two different time units.
  *
  * Think of the conversion method names as if they are written in-between
  * the two template parameters (i.e. "A <name> B").
+ *
+ * _origin_b should be the origin for conversion in the units of B.
+ * That is, there is some point in time _origin_b, such that:
+ *
+ *    to()   converts a time _origin_b + a into an offset from _origin_b in units of B.
+ *    from() converts a time _origin_b + b into an offset from _origin_b in units of A.
  */
 template<typename A, typename B>
-class TimeConverter {
+class LIBEVORAL_TEMPLATE_API TimeConverter {
 public:
 	TimeConverter () : _origin_b (0) {}
 	TimeConverter (B ob) : _origin_b (ob) {}
-	virtual ~TimeConverter() {}
+	virtual ~TimeConverter();
 
 	/** Convert A time to B time (A to B) */
 	virtual B to(A a) const = 0;
@@ -42,7 +50,7 @@ public:
 	B origin_b () const {
 		return _origin_b;
 	}
-	
+
 	void set_origin_b (B o) {
 		_origin_b = o;
 	}
@@ -52,13 +60,17 @@ protected:
 };
 
 
-/** A stub TimeConverter that simple statically casts between types. */
+/** A stub TimeConverter that simple statically casts between types.
+ *  _origin_b has no bearing here, as there is no time conversion
+ *  going on.
+ */
 template<typename A, typename B>
-class IdentityConverter : public TimeConverter<A,B> {
+class LIBEVORAL_TEMPLATE_API IdentityConverter : public TimeConverter<A,B> {
   public:
-        IdentityConverter() {}
-	B to(A a)   const { return static_cast<B>(a); }
-	A from(B b) const { return static_cast<A>(b); }
+	IdentityConverter() {}
+
+	B to(A a)   const;
+	A from(B b) const;
 };