Added an overlay effect, implementing the atop effect.

[movit] / overlay_effect_test.cpp

diff --git a/overlay_effect_test.cpp b/overlay_effect_test.cpp
new file mode 100644 (file)
index 0000000..009a757
--- /dev/null
+++ b/overlay_effect_test.cpp
@@ -0,0 +1,88 @@
+// Unit tests for OverlayEffect.
+
+#include "test_util.h"
+#include "gtest/gtest.h"
+#include "overlay_effect.h"
+
+TEST(OverlayEffectTest, TopDominatesBottomWhenNoAlpha) {
+       float data_a[] = {
+               0.0f, 0.25f,
+               0.75f, 1.0f,
+       };
+       float data_b[] = {
+               1.0f, 0.5f,
+               0.75f, 0.6f,
+       };
+       float out_data[4];
+       EffectChainTester tester(data_a, 2, 2, FORMAT_GRAYSCALE, COLORSPACE_sRGB, GAMMA_LINEAR);
+       Effect *input1 = tester.get_chain()->last_added_effect();
+       Effect *input2 = tester.add_input(data_b, FORMAT_GRAYSCALE, COLORSPACE_sRGB, GAMMA_LINEAR);
+
+       tester.get_chain()->add_effect(new OverlayEffect(), input1, input2);
+       tester.run(out_data, GL_RED, COLORSPACE_sRGB, GAMMA_LINEAR);
+
+       expect_equal(data_b, out_data, 2, 2);
+}
+
+TEST(OverlayEffectTest, BottomDominatesTopWhenTopIsTransparent) {
+       float data_a[] = {
+               1.0f, 0.0f, 0.0f, 0.5f,
+       };
+       float data_b[] = {
+               0.5f, 0.5f, 0.5f, 0.0f,
+       };
+       float out_data[4];
+       EffectChainTester tester(data_a, 1, 1, FORMAT_BGRA, COLORSPACE_sRGB, GAMMA_LINEAR);
+       Effect *input1 = tester.get_chain()->last_added_effect();
+       Effect *input2 = tester.add_input(data_b, FORMAT_BGRA, COLORSPACE_sRGB, GAMMA_LINEAR);
+
+       tester.get_chain()->add_effect(new OverlayEffect(), input1, input2);
+       tester.run(out_data, GL_BGRA, COLORSPACE_sRGB, GAMMA_LINEAR);
+
+       expect_equal(data_a, out_data, 4, 1);
+}
+
+TEST(OverlayEffectTest, ZeroAlphaBecomesAllZero) {
+       float data_a[] = {
+               0.0f, 0.25f, 0.5f, 0.0f
+       };
+       float data_b[] = {
+               1.0f, 1.0f, 1.0f, 0.0f
+       };
+       float expected_data[] = {
+               0.0f, 0.0f, 0.0f, 0.0f
+       };
+       float out_data[4];
+       EffectChainTester tester(data_a, 1, 1, FORMAT_BGRA, COLORSPACE_sRGB, GAMMA_LINEAR);
+       Effect *input1 = tester.get_chain()->last_added_effect();
+       Effect *input2 = tester.add_input(data_b, FORMAT_BGRA, COLORSPACE_sRGB, GAMMA_LINEAR);
+
+       tester.get_chain()->add_effect(new OverlayEffect(), input1, input2);
+       tester.run(out_data, GL_BGRA, COLORSPACE_sRGB, GAMMA_LINEAR);
+
+       expect_equal(expected_data, out_data, 4, 1);
+}
+
+// This is tested against what Photoshop does: (255,0,128, 0.25) over (128,255,0, 0.5)
+// becomes (179,153,51, 0.63). (Actually we fudge 0.63 to 0.625, because that's
+// what it should be.)
+TEST(OverlayEffectTest, PhotoshopReferenceTest) {
+       float data_a[] = {
+               128.0f/255.0f, 1.0f, 0.0f, 0.5f
+       };
+       float data_b[] = {
+               1.0f, 0.0f, 128.0f/255.0f, 0.25f
+       };
+       float expected_data[] = {
+               179.0f/255.0f, 153.0f/255.0f, 51.0f/255.0f, 0.625f
+       };
+       float out_data[4];
+       EffectChainTester tester(data_a, 1, 1, FORMAT_BGRA, COLORSPACE_sRGB, GAMMA_LINEAR);
+       Effect *input1 = tester.get_chain()->last_added_effect();
+       Effect *input2 = tester.add_input(data_b, FORMAT_BGRA, COLORSPACE_sRGB, GAMMA_LINEAR);
+
+       tester.get_chain()->add_effect(new OverlayEffect(), input1, input2);
+       tester.run(out_data, GL_BGRA, COLORSPACE_sRGB, GAMMA_LINEAR);
+
+       expect_equal(expected_data, out_data, 4, 1);
+}