+// Unit tests for DiffusionEffect.
+
+#include "test_util.h"
+#include "gtest/gtest.h"
+#include "diffusion_effect.h"
+
+TEST(DiffusionEffectTest, IdentityTransformDoesNothing) {
+ const int size = 4;
+
+ float data[size * size] = {
+ 0.0, 1.0, 0.0, 1.0,
+ 0.0, 1.0, 1.0, 0.0,
+ 0.0, 0.5, 1.0, 0.5,
+ 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 *diffusion_effect = tester.get_chain()->add_effect(new DiffusionEffect());
+ ASSERT_TRUE(diffusion_effect->set_float("radius", 0.0f));
+ tester.run(out_data, GL_RED, COLORSPACE_sRGB, GAMMA_LINEAR);
+
+ expect_equal(data, out_data, size, size);
+}
+
+TEST(DiffusionEffectTest, FlattensOutWhitePyramid) {
+ const int size = 9;
+
+ 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, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
+ 0.0, 0.0, 0.5, 0.5, 0.5, 0.5, 0.5, 0.0, 0.0,
+ 0.0, 0.0, 0.5, 0.7, 0.7, 0.7, 0.5, 0.0, 0.0,
+ 0.0, 0.0, 0.5, 0.7, 1.0, 0.7, 0.5, 0.0, 0.0,
+ 0.0, 0.0, 0.5, 0.7, 0.7, 0.7, 0.5, 0.0, 0.0,
+ 0.0, 0.0, 0.5, 0.5, 0.5, 0.5, 0.5, 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,
+ };
+ 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, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
+ 0.0, 0.0, 0.4, 0.4, 0.4, 0.4, 0.4, 0.0, 0.0,
+ 0.0, 0.0, 0.4, 0.5, 0.5, 0.5, 0.4, 0.0, 0.0,
+ 0.0, 0.0, 0.4, 0.5, 0.6, 0.5, 0.4, 0.0, 0.0,
+ 0.0, 0.0, 0.4, 0.5, 0.5, 0.5, 0.4, 0.0, 0.0,
+ 0.0, 0.0, 0.4, 0.4, 0.4, 0.4, 0.4, 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,
+ };
+ float out_data[size * size];
+
+ EffectChainTester tester(data, size, size, FORMAT_GRAYSCALE, COLORSPACE_sRGB, GAMMA_LINEAR);
+ Effect *diffusion_effect = tester.get_chain()->add_effect(new DiffusionEffect());
+ ASSERT_TRUE(diffusion_effect->set_float("radius", 2.0f));
+ ASSERT_TRUE(diffusion_effect->set_float("blurred_mix_amount", 0.7f));
+ tester.run(out_data, GL_RED, COLORSPACE_sRGB, GAMMA_LINEAR);
+
+ expect_equal(expected_data, out_data, size, size, 0.05f, 0.002);
+}