Express colour conversions as chromaticities and adjust so that

everything is specified as something_to_xyz and then you can get
an inverse LUT if you want one.

4 files changed, 22 insertions, 20 deletions

diff --git a/test/colour_conversion_test.cc b/test/colour_conversion_test.cc
index 9111b918..2eb5edf5 100644
--- a/test/colour_conversion_test.cc
+++ b/test/colour_conversion_test.cc
@@ -28,9 +28,9 @@ using boost::shared_ptr;
 using namespace dcp;
 
 static void
-check_gamma (shared_ptr<const TransferFunction> tf, int bit_depth, float gamma)
+check_gamma (shared_ptr<const TransferFunction> tf, int bit_depth, bool inverse, float gamma)
 {
-	double const * lut = tf->lut (bit_depth);
+	double const * lut = tf->lut (bit_depth, inverse);
 	int const count = rint (pow (2.0, bit_depth));
 
 	for (int i = 0; i < count; ++i) {
@@ -39,9 +39,9 @@ check_gamma (shared_ptr<const TransferFunction> tf, int bit_depth, float gamma)
 }
 
 static void
-check_modified_gamma (shared_ptr<const TransferFunction> tf, int bit_depth, double power, double threshold, double A, double B)
+check_modified_gamma (shared_ptr<const TransferFunction> tf, int bit_depth, bool inverse, double power, double threshold, double A, double B)
 {
-	double const * lut = tf->lut (bit_depth);
+	double const * lut = tf->lut (bit_depth, inverse);
 	int const count = rint (pow (2.0, bit_depth));
 
 	for (int i = 0; i < count; ++i) {
@@ -58,25 +58,25 @@ BOOST_AUTO_TEST_CASE (colour_conversion_test1)
 {
 	ColourConversion cc = ColourConversion::srgb_to_xyz ();
 
-	check_modified_gamma (cc.in(), 8, 2.4, 0.04045, 0.055, 12.92);
-	check_modified_gamma (cc.in(), 12, 2.4, 0.04045, 0.055, 12.92);
-	check_modified_gamma (cc.in(), 16, 2.4, 0.04045, 0.055, 12.92);
+	check_modified_gamma (cc.in(), 8, false, 2.4, 0.04045, 0.055, 12.92);
+	check_modified_gamma (cc.in(), 12, false, 2.4, 0.04045, 0.055, 12.92);
+	check_modified_gamma (cc.in(), 16, false, 2.4, 0.04045, 0.055, 12.92);
 
-	check_gamma (cc.out(), 8, 1 / 2.6);
-	check_gamma (cc.out(), 12, 1 / 2.6);
-	check_gamma (cc.out(), 16, 1 / 2.6);
+	check_gamma (cc.out(), 8, true, 1 / 2.6);
+	check_gamma (cc.out(), 12, true, 1 / 2.6);
+	check_gamma (cc.out(), 16, true, 1 / 2.6);
 }
 
 BOOST_AUTO_TEST_CASE (colour_conversion_test2)
 {
 	ColourConversion cc = ColourConversion::rec709_to_xyz ();
 
-	check_modified_gamma (cc.in(), 8, 1 / 0.45, 0.081, 0.099, 4.5);
-	check_modified_gamma (cc.in(), 12, 1 / 0.45, 0.081, 0.099, 4.5);
-	check_modified_gamma (cc.in(), 16, 1 / 0.45, 0.081, 0.099, 4.5);
+	check_modified_gamma (cc.in(), 8, false, 1 / 0.45, 0.081, 0.099, 4.5);
+	check_modified_gamma (cc.in(), 12, false, 1 / 0.45, 0.081, 0.099, 4.5);
+	check_modified_gamma (cc.in(), 16, false, 1 / 0.45, 0.081, 0.099, 4.5);
 
-	check_gamma (cc.out(), 8, 1 / 2.6);
-	check_gamma (cc.out(), 12, 1 / 2.6);
-	check_gamma (cc.out(), 16, 1 / 2.6);
+	check_gamma (cc.out(), 8, true, 1 / 2.6);
+	check_gamma (cc.out(), 12, true, 1 / 2.6);
+	check_gamma (cc.out(), 16, true, 1 / 2.6);
 }
 
diff --git a/test/decryption_test.cc b/test/decryption_test.cc
index 282e74f3..0080fe3e 100644
--- a/test/decryption_test.cc
+++ b/test/decryption_test.cc
@@ -50,7 +50,7 @@ get_frame (dcp::DCP const & dcp)
 	shared_ptr<dcp::XYZImage> xyz = j2k_frame->xyz_image();
 
 	uint8_t* argb = new uint8_t[xyz->size().width * xyz->size().height * 4];
-	dcp::xyz_to_rgba (j2k_frame->xyz_image(), dcp::ColourConversion::xyz_to_srgb(), argb);
+	dcp::xyz_to_rgba (j2k_frame->xyz_image(), dcp::ColourConversion::srgb_to_xyz(), argb);
 	return make_pair (argb, xyz->size ());
 }
 
diff --git a/test/rgb_xyz_test.cc b/test/rgb_xyz_test.cc
index 26411870..0b427893 100644
--- a/test/rgb_xyz_test.cc
+++ b/test/rgb_xyz_test.cc
@@ -134,7 +134,9 @@ BOOST_AUTO_TEST_CASE (xyz_rgb_range_test)
 	scoped_array<uint8_t> rgb (new uint8_t[2 * 2 * 6]);
 
 	notes.clear ();
-	dcp::xyz_to_rgb (xyz, dcp::ColourConversion::xyz_to_srgb (), rgb.get(), 2 * 6, boost::optional<dcp::NoteHandler> (boost::bind (&note_handler, _1, _2)));
+	dcp::xyz_to_rgb (
+		xyz, dcp::ColourConversion::srgb_to_xyz (), rgb.get(), 2 * 6, boost::optional<dcp::NoteHandler> (boost::bind (&note_handler, _1, _2))
+		);
 
 	/* The 6 out-of-range samples should have been noted */
 	BOOST_REQUIRE_EQUAL (notes.size(), 6);
diff --git a/test/round_trip_test.cc b/test/round_trip_test.cc
index dcaa6939..9f1030da 100644
--- a/test/round_trip_test.cc
+++ b/test/round_trip_test.cc
@@ -110,10 +110,10 @@ BOOST_AUTO_TEST_CASE (round_trip_test)
 	shared_ptr<dcp::XYZImage> xyz_B = mxf_B->get_frame(0)->xyz_image ();
 
 	scoped_array<uint8_t> frame_A (new uint8_t[xyz_A->size().width * xyz_A->size().height * 4]);
-	dcp::xyz_to_rgba (xyz_A, dcp::ColourConversion::xyz_to_srgb(), frame_A.get());
+	dcp::xyz_to_rgba (xyz_A, dcp::ColourConversion::srgb_to_xyz(), frame_A.get());
 	
 	scoped_array<uint8_t> frame_B (new uint8_t[xyz_B->size().width * xyz_B->size().height * 4]);
-	dcp::xyz_to_rgba (xyz_B, dcp::ColourConversion::xyz_to_srgb(), frame_B.get());
+	dcp::xyz_to_rgba (xyz_B, dcp::ColourConversion::srgb_to_xyz(), frame_B.get());
 
 	BOOST_CHECK_EQUAL (xyz_A->size().width, xyz_B->size().width);
 	BOOST_CHECK_EQUAL (xyz_A->size().height, xyz_B->size().height);