// the texel center right (everything is nicely symmetric).
// The approximate magnitudes have been checked against ImageMagick.
float expected_data[size * size] = {
- 0.0045, -0.0067, -0.0598, -0.0067, 0.0045,
- -0.0067, 0.0099, 0.0886, 0.0099, -0.0067,
- -0.0598, 0.0886, 0.7930, 0.0886, -0.0598,
- -0.0067, 0.0099, 0.0886, 0.0099, -0.0067,
- 0.0045, -0.0067, -0.0598, -0.0067, 0.0045,
+ 0.0045, -0.0067, -0.0599, -0.0067, 0.0045,
+ -0.0067, 0.0100, 0.0892, 0.0100, -0.0067,
+ -0.0599, 0.0890, 0.7925, 0.0892, -0.0599,
+ -0.0067, 0.0100, 0.0890, 0.0100, -0.0067,
+ 0.0045, -0.0067, -0.0599, -0.0067, 0.0045,
};
float data[size * size * 4], out_data[size * size];
// Require that we are within 10-bit accuracy. Note that this limit is for
// one pass only, but the limit is tight enough that it should be good enough
// for 10-bit accuracy even after two passes.
- expect_equal(expected_data, out_data, dwidth, dheight, 0.1 / 1023.0);
+ expect_equal(expected_data, out_data, dwidth, dheight, 0.12 / 1023.0);
}
TEST(ResampleEffectTest, ReadWholePixelFromLeft) {
// 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);
+ 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);
+ expect_equal(expected_data, out_data, dst_width, 1, 1.5f / 255.0f, 0.4f / 255.0f);
}
TEST(ResampleEffectTest, Zoom) {
expect_equal(expected_data, out_data, width, height);
}
+TEST(ResampleEffectTest, Precision) {
+ const int size = 1920; // Difficult non-power-of-two size.
+ const int offset = 5;
+
+ // Deliberately put the data of interest very close to the right,
+ // where texture coordinates are farther from 0 and thus less precise.
+ float data[size] = {0};
+ data[size - offset] = 1.0f;
+ float expected_data[size * 2] = {0};
+ for (int x = 0; x < size * 2; ++x) {
+ expected_data[x] = lanczos((x - (size - 2 * offset + 1) + 0.5f) * 0.5f, 3.0f);
+ }
+ float out_data[size * 2];
+
+ EffectChainTester tester(data, size * 2, 1, FORMAT_GRAYSCALE, COLORSPACE_sRGB, GAMMA_LINEAR);
+ Effect *resample_effect = tester.get_chain()->add_effect(new ResampleEffect());
+ ASSERT_TRUE(resample_effect->set_int("width", size * 2));
+ ASSERT_TRUE(resample_effect->set_int("height", 1));
+ 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, size, 1);
+}
+
} // namespace movit