X-Git-Url: https://main.carlh.net/gitweb/?a=blobdiff_plain;f=libs%2Fardour%2Fardour%2Fchan_count.h;h=b5699b6743b34743b0e1a84f849baa4f6a482861;hb=ae71e57e2422466716c0ec68ac841d778cf26e94;hp=03e2fcd8fff58b27685f81710dd188381be959a4;hpb=2ba2a50decb4b2f8b6b688dea495a2898124cc4f;p=ardour.git

diff --git a/libs/ardour/ardour/chan_count.h b/libs/ardour/ardour/chan_count.h
index 03e2fcd8ff..b5699b6743 100644
--- a/libs/ardour/ardour/chan_count.h
+++ b/libs/ardour/ardour/chan_count.h
@@ -38,34 +38,61 @@ namespace ARDOUR {
  * Operators are defined so this may safely be used as if it were a simple
  * (single-typed) integer count of channels.
  */
-class ChanCount {
+class LIBARDOUR_API ChanCount {
 public:
 	ChanCount(const XMLNode& node);
 	ChanCount() { reset(); }
 
-	// Convenience constructor for making single-typed streams (stereo, mono, etc)
-	ChanCount(DataType type, uint32_t channels) {
+	/** Convenience constructor for making single-typed streams (mono, stereo, midi, etc)
+	 * @param type data type
+	 * @param count number of channels
+	 */
+	ChanCount(DataType type, uint32_t count) {
 		reset();
-		set(type, channels);
+		set(type, count);
 	}
 
+	/** zero count of all data types */
 	void reset() {
 		for (DataType::iterator t = DataType::begin(); t != DataType::end(); ++t) {
 			_counts[*t] = 0;
 		}
 	}
 
+	/** set channel count for given type
+	 * @param type data type
+	 * @param count number of channels
+	 */
 	void     set(DataType t, uint32_t count) { assert(t != DataType::NIL); _counts[t] = count; }
+	/** query channel count for given type
+	 * @param type data type
+	 * @returns channel count for given type
+	 */
 	uint32_t get(DataType t) const { assert(t != DataType::NIL); return _counts[t]; }
 
 	inline uint32_t n (DataType t) const { return _counts[t]; }
 
+	/** query number of audio channels
+	 * @returns number of audio channels
+	 */
 	inline uint32_t n_audio() const { return _counts[DataType::AUDIO]; }
+	/** set number of audio channels
+	 * @param a number of audio channels
+	 */
 	inline void set_audio(uint32_t a) { _counts[DataType::AUDIO] = a; }
 
+	/** query number of midi channels
+	 * @returns number of midi channels
+	 */
 	inline uint32_t n_midi()  const { return _counts[DataType::MIDI]; }
+	/** set number of audio channels
+	 * @param m number of midi channels
+	 */
 	inline void set_midi(uint32_t m) { _counts[DataType::MIDI] = m; }
 
+	/** query total channel count of all data types
+	 * @returns total channel count (audio + midi)
+	 */
 	uint32_t n_total() const {
 		uint32_t ret = 0;
 		for (uint32_t i=0; i < DataType::num_types; ++i)
@@ -120,6 +147,39 @@ public:
 		return ret;
 	}
 
+	/** underflow safe subtraction */
+	ChanCount operator-(const ChanCount& other) const {
+		ChanCount ret;
+		for (DataType::iterator t = DataType::begin(); t != DataType::end(); ++t) {
+			if (get(*t) < other.get(*t)) {
+				ret.set(*t, 0);
+			} else {
+				ret.set(*t, get(*t) - other.get(*t));
+			}
+		}
+		return ret;
+	}
+
+	ChanCount operator*(const unsigned int factor) const {
+		ChanCount ret;
+		for (DataType::iterator t = DataType::begin(); t != DataType::end(); ++t) {
+			ret.set(*t, get(*t) * factor );
+		}
+		return ret;
+	}
+
+	/** underflow safe subtraction */
+	ChanCount& operator-=(const ChanCount& other) {
+		for (DataType::iterator t = DataType::begin(); t != DataType::end(); ++t) {
+			if (_counts[*t] < other._counts[*t]) {
+				_counts[*t] = 0;
+			} else {
+				_counts[*t] -= other._counts[*t];
+			}
+		}
+		return *this;
+	}
+
 	ChanCount& operator+=(const ChanCount& other) {
 		for (DataType::iterator t = DataType::begin(); t != DataType::end(); ++t) {
 			_counts[*t] += other._counts[*t];
@@ -154,7 +214,7 @@ private:
 
 } // namespace ARDOUR
 
-std::ostream& operator<<(std::ostream& o, const ARDOUR::ChanCount& c);
+LIBARDOUR_API std::ostream& operator<<(std::ostream& o, const ARDOUR::ChanCount& c);
 
 #endif // __ardour_chan_count_h__