Loosen up the 0.499 vs. 0.501 subpixel resample test.

[movit] / resample_effect_test.cpp

diff --git a/resample_effect_test.cpp b/resample_effect_test.cpp
index 95c2bcfb9aec95693653ea65572cfdca76f79699..e90f19ec77ee3baa6da9225790a981858ba41ef4 100644 (file)
--- a/resample_effect_test.cpp
+++ b/resample_effect_test.cpp
@@ -208,4 +208,197 @@ TEST(ResampleEffectTest, HeavyResampleGetsSumRight) {
        expect_equal(expected_data, out_data, dwidth, dheight, 0.1 / 1023.0);
 }
 
+TEST(ResampleEffectTest, ReadWholePixelFromLeft) {
+       const int size = 5;
+
+       float data[size * size] = {
+               0.0, 0.0, 0.0, 0.0, 0.0,
+               0.0, 0.0, 0.0, 0.0, 0.0,
+               0.0, 0.0, 1.0, 0.0, 0.0,
+               0.0, 0.0, 0.0, 0.0, 0.0,
+               0.0, 0.0, 0.0, 0.0, 0.0,
+       };
+       float expected_data[size * size] = {
+               0.0, 0.0, 0.0, 0.0, 0.0,
+               0.0, 0.0, 0.0, 0.0, 0.0,
+               0.0, 1.0, 0.0, 0.0, 0.0,
+               0.0, 0.0, 0.0, 0.0, 0.0,
+               0.0, 0.0, 0.0, 0.0, 0.0,
+       };
+       float out_data[size * size];
+
+       EffectChainTester tester(data, size, size, FORMAT_GRAYSCALE, COLORSPACE_sRGB, GAMMA_LINEAR);
+       Effect *resample_effect = tester.get_chain()->add_effect(new ResampleEffect());
+       ASSERT_TRUE(resample_effect->set_int("width", size));
+       ASSERT_TRUE(resample_effect->set_int("height", size));
+       ASSERT_TRUE(resample_effect->set_float("left", 1.0f));
+       tester.run(out_data, GL_RED, COLORSPACE_sRGB, GAMMA_LINEAR);
+
+       expect_equal(expected_data, out_data, size, size);
+}
+
+TEST(ResampleEffectTest, ReadQuarterPixelFromLeft) {
+       const int size = 5;
+
+       float data[size * size] = {
+               0.0, 0.0, 0.0, 0.0, 0.0,
+               0.0, 0.0, 0.0, 0.0, 0.0,
+               0.0, 0.0, 1.0, 0.0, 0.0,
+               0.0, 0.0, 0.0, 0.0, 0.0,
+               0.0, 0.0, 0.0, 0.0, 0.0,
+       };
+
+       float expected_data[size * size] = {
+               0.0, 0.0, 0.0, 0.0, 0.0,
+               0.0, 0.0, 0.0, 0.0, 0.0,
+
+               // sin(x*pi)/(x*pi) * sin(x*pi/3)/(x*pi/3) for
+               // x = -1.75, -0.75, 0.25, 1.25, 2.25.
+               // Note that the weight is mostly on the left side.
+               -0.06779, 0.27019, 0.89007, -0.13287, 0.03002,
+
+               0.0, 0.0, 0.0, 0.0, 0.0,
+               0.0, 0.0, 0.0, 0.0, 0.0,
+       };
+       float out_data[size * size];
+
+       EffectChainTester tester(data, size, size, FORMAT_GRAYSCALE, COLORSPACE_sRGB, GAMMA_LINEAR);
+       Effect *resample_effect = tester.get_chain()->add_effect(new ResampleEffect());
+       ASSERT_TRUE(resample_effect->set_int("width", size));
+       ASSERT_TRUE(resample_effect->set_int("height", size));
+       ASSERT_TRUE(resample_effect->set_float("left", 0.25f));
+       tester.run(out_data, GL_RED, COLORSPACE_sRGB, GAMMA_LINEAR);
+
+       expect_equal(expected_data, out_data, size, size);
+}
+
+TEST(ResampleEffectTest, ReadQuarterPixelFromTop) {
+       const int width = 3;
+       const int height = 5;
+
+       float data[width * height] = {
+               0.0, 0.0, 0.0,
+               0.0, 0.0, 0.0,
+               1.0, 0.0, 0.0,
+               0.0, 0.0, 0.0,
+               0.0, 0.0, 0.0,
+       };
+
+       // See ReadQuarterPixelFromLeft for explanation of the data.
+       float expected_data[width * height] = {
+               -0.06779, 0.0, 0.0,
+                0.27019, 0.0, 0.0,
+                0.89007, 0.0, 0.0,
+               -0.13287, 0.0, 0.0,
+                0.03002, 0.0, 0.0,
+       };
+       float out_data[width * height];
+
+       EffectChainTester tester(data, width, height, FORMAT_GRAYSCALE, COLORSPACE_sRGB, GAMMA_LINEAR);
+       Effect *resample_effect = tester.get_chain()->add_effect(new ResampleEffect());
+       ASSERT_TRUE(resample_effect->set_int("width", width));
+       ASSERT_TRUE(resample_effect->set_int("height", height));
+       ASSERT_TRUE(resample_effect->set_float("top", 0.25f));
+       tester.run(out_data, GL_RED, COLORSPACE_sRGB, GAMMA_LINEAR);
+
+       expect_equal(expected_data, out_data, width, height);
+}
+
+TEST(ResampleEffectTest, ReadHalfPixelFromLeftAndScale) {
+       const int src_width = 4;
+       const int dst_width = 8;
+
+       float data[src_width * 1] = {
+               1.0, 2.0, 3.0, 4.0,
+       };
+       float expected_data[dst_width * 1] = {
+               // Empirical; the real test is that we are the same for 0.499 and 0.501.
+               1.1553, 1.7158, 2.2500, 2.7461, 3.2812, 3.8418, 4.0703, 4.0508
+       };
+       float out_data[dst_width * 1];
+
+       EffectChainTester tester(NULL, dst_width, 1, FORMAT_GRAYSCALE, COLORSPACE_sRGB, GAMMA_LINEAR);
+
+       ImageFormat format;
+       format.color_space = COLORSPACE_sRGB;
+       format.gamma_curve = GAMMA_LINEAR;
+
+       FlatInput *input = new FlatInput(format, FORMAT_GRAYSCALE, GL_FLOAT, src_width, 1);
+       input->set_pixel_data(data);
+       tester.get_chain()->add_input(input);
+
+       Effect *resample_effect = tester.get_chain()->add_effect(new ResampleEffect());
+       ASSERT_TRUE(resample_effect->set_int("width", dst_width));
+       ASSERT_TRUE(resample_effect->set_int("height", 1));
+
+       // Check that we are (almost) the same no matter the rounding.
+       ASSERT_TRUE(resample_effect->set_float("left", 0.499f));
+       tester.run(out_data, GL_RED, COLORSPACE_sRGB, GAMMA_LINEAR);
+       expect_equal(expected_data, out_data, dst_width, 1, 1.5f / 255.0f, 0.4f / 255.0f);
+
+       ASSERT_TRUE(resample_effect->set_float("left", 0.501f));
+       tester.run(out_data, GL_RED, COLORSPACE_sRGB, GAMMA_LINEAR);
+       expect_equal(expected_data, out_data, dst_width, 1, 1.5f / 255.0f, 0.4f / 255.0f);
+}
+
+TEST(ResampleEffectTest, Zoom) {
+       const int width = 5;
+       const int height = 3;
+
+       float data[width * height] = {
+               0.0, 0.0, 0.0, 0.0, 0.0,
+               0.2, 0.4, 0.6, 0.4, 0.2,
+               0.0, 0.0, 0.0, 0.0, 0.0,
+       };
+       float expected_data[width * height] = {
+               0.0, 0.0,    0.0, 0.0,    0.0,
+               0.4, 0.5396, 0.6, 0.5396, 0.4,
+               0.0, 0.0,    0.0, 0.0,    0.0,
+       };
+       float out_data[width * height];
+
+       EffectChainTester tester(data, width, height, FORMAT_GRAYSCALE, COLORSPACE_sRGB, GAMMA_LINEAR);
+       Effect *resample_effect = tester.get_chain()->add_effect(new ResampleEffect());
+       ASSERT_TRUE(resample_effect->set_int("width", width));
+       ASSERT_TRUE(resample_effect->set_int("height", height));
+       ASSERT_TRUE(resample_effect->set_float("zoom_x", 2.0f));
+       tester.run(out_data, GL_RED, COLORSPACE_sRGB, GAMMA_LINEAR);
+
+       expect_equal(expected_data, out_data, width, height);
+}
+
+TEST(ResampleEffectTest, VerticalZoomFromTop) {
+       const int width = 5;
+       const int height = 5;
+
+       float data[width * height] = {
+               0.2, 0.4, 0.6, 0.4, 0.2,
+               0.0, 0.0, 0.0, 0.0, 0.0,
+               0.0, 0.0, 0.0, 0.0, 0.0,
+               0.0, 0.0, 0.0, 0.0, 0.0,
+               0.0, 0.0, 0.0, 0.0, 0.0,
+       };
+
+       // Largely empirical data; the main point is that the top line
+       // is unchanged, since that's our zooming point.
+       float expected_data[width * height] = {
+                0.2000,  0.4000,  0.6000,  0.4000,  0.2000,
+                0.1389,  0.2778,  0.4167,  0.2778,  0.1389,
+                0.0600,  0.1199,  0.1798,  0.1199,  0.0600,
+                0.0000,  0.0000,  0.0000,  0.0000,  0.0000,
+               -0.0229, -0.0459, -0.0688, -0.0459, -0.0229,
+       };
+       float out_data[width * height];
+
+       EffectChainTester tester(data, width, height, FORMAT_GRAYSCALE, COLORSPACE_sRGB, GAMMA_LINEAR);
+       Effect *resample_effect = tester.get_chain()->add_effect(new ResampleEffect());
+       ASSERT_TRUE(resample_effect->set_int("width", width));
+       ASSERT_TRUE(resample_effect->set_int("height", height));
+       ASSERT_TRUE(resample_effect->set_float("zoom_y", 3.0f));
+       ASSERT_TRUE(resample_effect->set_float("zoom_center_y", 0.5f / height));
+       tester.run(out_data, GL_RED, COLORSPACE_sRGB, GAMMA_LINEAR);
+
+       expect_equal(expected_data, out_data, width, height);
+}
+
 }  // namespace movit