Hacks.

[libdcp.git] / test / rgb_xyz_test.cc

diff --git a/test/rgb_xyz_test.cc b/test/rgb_xyz_test.cc
index 54f6174ca61a77d5be608e98b37f3d7f0da21783..007879389bf0b7376967f5b69c52739825a98505 100644 (file)
--- a/test/rgb_xyz_test.cc
+++ b/test/rgb_xyz_test.cc
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2014-2019 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2014-2021 Carl Hetherington <cth@carlh.net>
 
     This file is part of libdcp.
 
@@ -31,24 +31,31 @@
     files in the program, then also delete it here.
 */
 
-#include "rgb_xyz.h"
-#include "openjpeg_image.h"
+
 #include "colour_conversion.h"
-#include <boost/test/unit_test.hpp>
+#include "openjpeg_image.h"
+#include "piecewise_lut.h"
+#include "rgb_xyz.h"
+#include "stream_operators.h"
 #include <boost/bind.hpp>
+#include <boost/random.hpp>
 #include <boost/scoped_array.hpp>
+#include <boost/test/unit_test.hpp>
+
 
-using std::max;
-using std::list;
-using std::string;
 using std::cout;
-using std::shared_ptr;
+using std::list;
 using std::make_shared;
+using std::max;
+using std::shared_ptr;
+using std::string;
 using boost::optional;
 using boost::scoped_array;
 
-/** Convert a test image from sRGB to XYZ and check that the transforms are right */
-BOOST_AUTO_TEST_CASE (rgb_xyz_test)
+
+static
+void
+rgb_xyz_test_case (std::function<void (uint16_t*)> write_pixel)
 {
        srand (0);
        dcp::Size const size (640, 480);
@@ -57,11 +64,8 @@ BOOST_AUTO_TEST_CASE (rgb_xyz_test)
        for (int y = 0; y < size.height; ++y) {
                uint16_t* p = reinterpret_cast<uint16_t*> (rgb.get() + y * size.width * 6);
                for (int x = 0; x < size.width; ++x) {
-                       /* Write a 12-bit random number for each component */
-                       for (int c = 0; c < 3; ++c) {
-                               *p = (rand () & 0xfff) << 4;
-                               ++p;
-                       }
+                       write_pixel (p);
+                       p += 3;
                }
        }
 
@@ -120,6 +124,44 @@ BOOST_AUTO_TEST_CASE (rgb_xyz_test)
        }
 }
 
+
+/** Convert a test image from sRGB to XYZ and check that the transforms are right */
+BOOST_AUTO_TEST_CASE (rgb_xyz_test)
+{
+       {
+               int counter = 0;
+               rgb_xyz_test_case ([&counter](uint16_t* p) {
+                       p[0] = p[1] = p[2] = (counter << 4);
+                       ++counter;
+                       if (counter >= 4096) {
+                               counter = 0;
+                       }
+               });
+       }
+
+       boost::random::mt19937 rng(1);
+       boost::random::uniform_int_distribution<> dist(0, 4095);
+
+       rgb_xyz_test_case ([&rng, &dist](uint16_t* p) {
+                          p[0] = dist(rng) << 4;
+                          p[1] = dist(rng) << 4;
+                          p[2] = dist(rng) << 4;
+                          });
+}
+
+
+/** Check the piecewise LUT that is used for inverse gamma calculation */
+BOOST_AUTO_TEST_CASE (rgb_xyz_lut_test)
+{
+       auto conversion = dcp::ColourConversion::rec709_to_xyz();
+       auto lut = dcp::make_inverse_gamma_lut(conversion.out());
+
+       for (double x = 0; x < 1; x += 0.000001) {
+               BOOST_CHECK(std::abs(lrint(lut.lookup(x) * 4095) - lrint(pow(x, 1 / 2.6) * 4095)) < 2);
+       }
+}
+
+
 static list<string> notes;
 
 static void
@@ -155,7 +197,7 @@ BOOST_AUTO_TEST_CASE (xyz_rgb_range_test)
                );
 
        /* The 6 out-of-range samples should have been noted */
-       BOOST_REQUIRE_EQUAL (notes.size(), 6);
+       BOOST_REQUIRE_EQUAL (notes.size(), 6U);
        auto i = notes.begin ();
        BOOST_REQUIRE_EQUAL (*i++, "XYZ value -4 out of range");
        BOOST_REQUIRE_EQUAL (*i++, "XYZ value -4 out of range");