Add AudioMapping::take_from().

3 files changed, 61 insertions, 0 deletions

diff --git a/src/lib/audio_mapping.cc b/src/lib/audio_mapping.cc
index 74b33aa35..b8aa6249f 100644
--- a/src/lib/audio_mapping.cc
+++ b/src/lib/audio_mapping.cc
@@ -288,3 +288,18 @@ AudioMapping::unmap_all ()
 		}
 	}
 }
+
+
+void
+AudioMapping::take_from(AudioMapping const& other)
+{
+	auto input = std::min(input_channels(), other.input_channels());
+	auto output = std::min(output_channels(), other.output_channels());
+
+	for (auto i = 0; i < input; ++i) {
+		for (auto o = 0; o < output; ++o) {
+			set(i, o, other.get(i, o));
+		}
+	}
+}
+
diff --git a/src/lib/audio_mapping.h b/src/lib/audio_mapping.h
index 0f59cc205..fe9a79789 100644
--- a/src/lib/audio_mapping.h
+++ b/src/lib/audio_mapping.h
@@ -76,6 +76,8 @@ public:
 	std::list<int> mapped_output_channels () const;
 	void unmap_all ();
 
+	void take_from(AudioMapping const& other);
+
 private:
 	void setup (int input_channels, int output_channels);
 
diff --git a/test/audio_mapping_test.cc b/test/audio_mapping_test.cc
index 37f3d2476..22412b260 100644
--- a/test/audio_mapping_test.cc
+++ b/test/audio_mapping_test.cc
@@ -104,3 +104,47 @@ BOOST_AUTO_TEST_CASE (audio_mapping_guess_test)
 }
 
 
+BOOST_AUTO_TEST_CASE(audio_mapping_take_from_larger)
+{
+	AudioMapping A(4, 9);
+	AudioMapping B(2, 3);
+
+	A.set(0, 0, 4);
+	A.set(1, 0, 8);
+	A.set(0, 1, 3);
+	A.set(1, 1, 6);
+	A.set(0, 2, 1);
+	A.set(1, 2, 9);
+
+	B.take_from(A);
+
+	BOOST_CHECK_CLOSE(B.get(0, 0), 4, 0.01);
+	BOOST_CHECK_CLOSE(B.get(1, 0), 8, 0.01);
+	BOOST_CHECK_CLOSE(B.get(0, 1), 3, 0.01);
+	BOOST_CHECK_CLOSE(B.get(1, 1), 6, 0.01);
+	BOOST_CHECK_CLOSE(B.get(0, 2), 1, 0.01);
+	BOOST_CHECK_CLOSE(B.get(1, 2), 9, 0.01);
+}
+
+
+BOOST_AUTO_TEST_CASE(audio_mapping_take_from_smaller)
+{
+	AudioMapping A(4, 9);
+	AudioMapping B(2, 3);
+
+	B.set(0, 0, 4);
+	B.set(1, 0, 8);
+	B.set(0, 1, 3);
+	B.set(1, 1, 6);
+	B.set(0, 2, 1);
+	B.set(1, 2, 9);
+
+	A.take_from(B);
+
+	BOOST_CHECK_CLOSE(A.get(0, 0), 4, 0.01);
+	BOOST_CHECK_CLOSE(A.get(1, 0), 8, 0.01);
+	BOOST_CHECK_CLOSE(A.get(0, 1), 3, 0.01);
+	BOOST_CHECK_CLOSE(A.get(1, 1), 6, 0.01);
+	BOOST_CHECK_CLOSE(A.get(0, 2), 1, 0.01);
+	BOOST_CHECK_CLOSE(A.get(1, 2), 9, 0.01);
+}