+ 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);
+}
+
+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);