--- /dev/null
+// Unit tests for BlurEffect.
+#include <math.h>
+
+#include "test_util.h"
+#include "gtest/gtest.h"
+#include "blur_effect.h"
+
+TEST(BlurEffectTest, 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 *blur_effect = tester.get_chain()->add_effect(new BlurEffect());
+ ASSERT_TRUE(blur_effect->set_float("radius", 0.0f));
+ tester.run(out_data, GL_RED, COLORSPACE_sRGB, GAMMA_LINEAR);
+
+ expect_equal(data, out_data, size, size);
+}
+
+namespace {
+
+void add_blurred_point(float *out, int size, int x0, int y0, float strength, float sigma)
+{
+ // From http://en.wikipedia.org/wiki/Logistic_distribution#Alternative_parameterization.
+ const float c1 = M_PI / (sigma * 4 * sqrt(3.0f));
+ const float c2 = M_PI / (sigma * 2.0 * sqrt(3.0f));
+
+ for (int y = 0; y < size; ++y) {
+ for (int x = 0; x < size; ++x) {
+ float xd = c2 * (x - x0);
+ float yd = c2 * (y - y0);
+ out[y * size + x] += (strength * c1 * c1) / (cosh(xd) * cosh(xd) * cosh(yd) * cosh(yd));
+ }
+ }
+}
+
+} // namespace
+
+TEST(BlurEffectTest, BlurTwoDotsSmallRadius) {
+ const float sigma = 3.0f;
+ const int size = 32;
+ const int x1 = 8;
+ const int y1 = 8;
+ const int x2 = 20;
+ const int y2 = 10;
+
+ float data[size * size], out_data[size * size], expected_data[size * size];
+ memset(data, 0, sizeof(data));
+ memset(expected_data, 0, sizeof(expected_data));
+
+ data[y1 * size + x1] = 1.0f;
+ data[y2 * size + x2] = 1.0f;
+
+ add_blurred_point(expected_data, size, x1, y1, 1.0f, sigma);
+ add_blurred_point(expected_data, size, x2, y2, 1.0f, sigma);
+
+ EffectChainTester tester(data, size, size, FORMAT_GRAYSCALE, COLORSPACE_sRGB, GAMMA_LINEAR);
+ Effect *blur_effect = tester.get_chain()->add_effect(new BlurEffect());
+ ASSERT_TRUE(blur_effect->set_float("radius", sigma));
+ tester.run(out_data, GL_RED, COLORSPACE_sRGB, GAMMA_LINEAR);
+
+ // Set the limits a bit tighter than usual, since there is so little energy in here.
+ expect_equal(expected_data, out_data, size, size, 1e-3, 1e-5);
+}
+
+TEST(BlurEffectTest, BlurTwoDotsLargeRadius) {
+ const float sigma = 20.0f; // Large enough that we will begin scaling.
+ const int size = 256;
+ const int x1 = 64;
+ const int y1 = 64;
+ const int x2 = 160;
+ const int y2 = 120;
+
+ static float data[size * size], out_data[size * size], expected_data[size * size];
+ memset(data, 0, sizeof(data));
+ memset(expected_data, 0, sizeof(expected_data));
+
+ data[y1 * size + x1] = 128.0f;
+ data[y2 * size + x2] = 128.0f;
+
+ add_blurred_point(expected_data, size, x1, y1, 128.0f, sigma);
+ add_blurred_point(expected_data, size, x2, y2, 128.0f, sigma);
+
+ EffectChainTester tester(data, size, size, FORMAT_GRAYSCALE, COLORSPACE_sRGB, GAMMA_LINEAR);
+ Effect *blur_effect = tester.get_chain()->add_effect(new BlurEffect());
+ ASSERT_TRUE(blur_effect->set_float("radius", sigma));
+ tester.run(out_data, GL_RED, COLORSPACE_sRGB, GAMMA_LINEAR);
+
+ expect_equal(expected_data, out_data, size, size, 0.1f, 1e-3);
+}