dcp::Size
scale_for_display (dcp::Size s, dcp::Size display_container, dcp::Size film_container, PixelQuanta quanta)
{
- /* Now scale it down if the display container is smaller than the film container */
- if (display_container != film_container) {
- float const scale = min (
- float (display_container.width) / film_container.width,
- float (display_container.height) / film_container.height
+ if (std::abs(display_container.ratio() - film_container.ratio()) < 0.01) {
+ /* The display ratio is very close to what it should be, but it might not be exactly the same.
+ * Allow the image to stretch slightly (differently in x and y) so that we are less likely
+ * to get single pixel gaps in the preview.
+ */
+ return quanta.round(
+ static_cast<float>(s.width) * display_container.width / film_container.width,
+ static_cast<float>(s.height) * display_container.height / film_container.height
);
-
- s.width = lrintf (s.width * scale);
- s.height = lrintf (s.height * scale);
- s = quanta.round (s);
+ } else {
+ /* The display ratio is quite different to the film, so scale it so that the dimension
+ * that needs to fit does fit.
+ */
+ auto const scale = min(
+ static_cast<float>(display_container.width) / film_container.width,
+ static_cast<float>(display_container.height) / film_container.height
+ );
+ return quanta.round(s.width * scale, s.height * scale);
}
-
- return s;
}
BOOST_CHECK(word_wrap("hello this is a longer bit of text and it should be word-wrapped", 31) == string{"hello this is a longer bit of \ntext and it should be word-\nwrapped\n"});
BOOST_CHECK_EQUAL(word_wrap("hellocan'twrapthissadly", 5), "hello\ncan't\nwrapt\nhissa\ndly\n");
}
+
+
+BOOST_AUTO_TEST_CASE(scale_for_display_test)
+{
+ /* 1998x1076 image in a flat frame, displayed in 1104x596.
+ * In the DCP there will be 2px black top and bottom.
+ * So the display width should definitely be 1104, and it then follows that
+ * the display height should be scaled by the same factor as the width has been.
+ */
+ BOOST_CHECK(scale_for_display(dcp::Size(1998, 1076), dcp::Size(1104, 596), dcp::Size(1998, 1080), PixelQuanta(2, 2)) == dcp::Size(1104, 594));
+
+ /* 1800x1080 image in a flat frame, displayed in 1104x596.
+ * In the DCP there should be 99px black left and right.
+ * So the display height should definitely be 596.
+ */
+ BOOST_CHECK(scale_for_display(dcp::Size(1800, 1080), dcp::Size(1104, 596), dcp::Size(1998, 1080), PixelQuanta(2, 2)) == dcp::Size(994, 596));
+
+ /* This happens sometimes as windows are getting resized */
+ BOOST_CHECK(scale_for_display(dcp::Size(1998, 1076), dcp::Size(64, 64), dcp::Size(1998, 1080), PixelQuanta(2, 2)) == dcp::Size(64, 34));
+}