Add alternative test image

Author: adrian-cojocaru

test/fixtures/tile_lod/pitchThreshold-line/expected.png

@@ -74,5 +74,12 @@ void checkImage(const std::string& base,
                 double imageThreshold = 0,
                 double pixelThreshold = 0);
 
+void checkImages(const std::vector<std::string>& possibleExpected,
+                 const PremultipliedImage& actual,
+                 double imageThreshold = 0,
+                 double pixelThreshold = 0);
+
+double getImageDiff(const std::string& base, const PremultipliedImage& actual, double pixelThreshold = 0);
+
 } // namespace test
 } // namespace mbgl

test/fixtures/tile_lod/pitchThreshold/expected.png renamed to test/fixtures/tile_lod/pitchThreshold-polyline/expected.png

@@ -9,23 +9,44 @@
 #pragma warning(disable : 4244)
 #endif
 
+#include <gmock/gmock-matchers.h>
+#include <gmock/gmock-more-matchers.h>
 #include <mapbox/pixelmatch.hpp>
 
 #ifdef _MSC_VER
 #pragma warning(pop)
 #endif
 
+using namespace ::testing;
+
 namespace mbgl {
 namespace test {
 
 void checkImage(const std::string& base,
                 const PremultipliedImage& actual,
                 double imageThreshold,
                 double pixelThreshold) {
+    EXPECT_LE(getImageDiff(base, actual, pixelThreshold), imageThreshold);
+}
+
+void checkImages(const std::vector<std::string>& possibleExpected,
+                 const PremultipliedImage& actual,
+                 double imageThreshold,
+                 double pixelThreshold) {
+    std::vector<double> diffs(0.0, possibleExpected.size());
+
+    for (const auto& expected : possibleExpected) {
+        diffs.push_back(getImageDiff(expected, actual, pixelThreshold));
+    }
+
+    EXPECT_THAT(diffs, Contains(Le(imageThreshold)));
+}
+
+double getImageDiff(const std::string& base, const PremultipliedImage& actual, double pixelThreshold) {
 #if !TEST_READ_ONLY
     if (getenv("UPDATE")) {
         util::write_file(base + "/expected.png", encodePNG(actual));
-        return;
+        return 0.0;
     }
 #endif
 
@@ -44,7 +65,9 @@ void checkImage(const std::string& base,
     util::write_file(base + "/actual.png", encodePNG(actual));
 #endif
 
-    ASSERT_EQ(expected.size, actual.size);
+    if (expected.size != actual.size) {
+        return 1.0;
+    }
 
     uint64_t pixels = mapbox::pixelmatch(actual.data.get(),
                                          expected.data.get(),
@@ -53,11 +76,11 @@ void checkImage(const std::string& base,
                                          diff.data.get(),
                                          pixelThreshold);
 
-    EXPECT_LE(static_cast<double>(pixels) / (expected.size.width * expected.size.height), imageThreshold);
-
 #if !TEST_READ_ONLY
     util::write_file(base + "/diff.png", encodePNG(diff));
 #endif
+
+    return static_cast<double>(pixels) / (expected.size.width * expected.size.height);
 }
 
 } // namespace test

test/include/mbgl/test/util.hpp

@@ -66,13 +66,21 @@ class TileLODTest {
         map.getStyle().addLayer(std::move(layer));
     }
 
-    void checkImage(std::string name, uint32_t expectedTileCount) {
-        const std::string imageDir = "test/fixtures/tile_lod/" + name;
+    void checkImage(std::string image, uint32_t expectedTileCount) {
+        checkImages(std::vector<std::string>{image}, expectedTileCount);
+    }
 
-        test::checkImage(imageDir, frontend.render(map).image, 0.0002, 0.1);
+    void checkImages(std::vector<std::string> images, uint32_t expectedTileCount) {
+        const auto result = frontend.render(map);
 
         // check this after frontend.render()
         EXPECT_EQ(tileCount, expectedTileCount);
+
+        std::transform(images.begin(), images.end(), images.begin(), [](const auto& img) {
+            return "test/fixtures/tile_lod/" + img;
+        });
+
+        test::checkImages(images, result.image, 0.0002, 0.01);
     }
 };
 
@@ -113,7 +121,12 @@ TEST(TileLOD, pitchThreshold) {
     test.tileCount = 0;
 
     test.map.jumpTo(CameraOptions().withPitch(pitch + 1.0));
-    test.checkImage("pitchThreshold", 22);
+    test.checkImages(
+        {
+            "pitchThreshold-line",
+            "pitchThreshold-polyline",
+        },
+        22);
 }
 
 TEST(TileLOD, scale) {