Hard-assert on something that has bitten me too many times now.

[movit] / resample_effect_test.cpp

diff --git a/resample_effect_test.cpp b/resample_effect_test.cpp
index 9a2801395464b958a917baa2f9f1a8a0b907b16f..02d9d74d1102ace6a956331bac2280f8a368060f 100644 (file)
--- a/resample_effect_test.cpp
+++ b/resample_effect_test.cpp
@@ -96,11 +96,11 @@ TEST(ResampleEffectTest, DownscaleByTwoGetsCorrectPixelCenters) {
        // 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];
 
@@ -162,8 +162,8 @@ TEST(ResampleEffectTest, UpscaleByThreeGetsCorrectPixelCenters) {
        EXPECT_FLOAT_EQ(1.0, out_data[7 * (size * 3) + 7]);
        for (unsigned y = 0; y < size * 3; ++y) {
                for (unsigned x = 0; x < size * 3; ++x) {
-                       EXPECT_FLOAT_EQ(out_data[y * (size * 3) + x], out_data[(size * 3 - y - 1) * (size * 3) + x]);
-                       EXPECT_FLOAT_EQ(out_data[y * (size * 3) + x], out_data[y * (size * 3) + (size * 3 - x - 1)]);
+                       EXPECT_NEAR(out_data[y * (size * 3) + x], out_data[(size * 3 - y - 1) * (size * 3) + x], 1e-6);
+                       EXPECT_NEAR(out_data[y * (size * 3) + x], out_data[y * (size * 3) + (size * 3 - x - 1)], 1e-6);
                }
        }
 }
@@ -205,7 +205,7 @@ TEST(ResampleEffectTest, HeavyResampleGetsSumRight) {
        // 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) {
@@ -334,11 +334,11 @@ TEST(ResampleEffectTest, ReadHalfPixelFromLeftAndScale) {
        // 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) {
@@ -401,4 +401,28 @@ TEST(ResampleEffectTest, VerticalZoomFromTop) {
        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 * 2] = {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