[render tests][tile mode] Enable automatic labels cut-off detection

4 files changed, 68 insertions, 4 deletions

diff --git a/render-test/metadata.hpp b/render-test/metadata.hpp
index e64e07ffc3..e40d3773b0 100644
--- a/render-test/metadata.hpp
+++ b/render-test/metadata.hpp
@@ -175,6 +175,7 @@ struct TestMetadata {
     unsigned metricsFailed = 0;
     unsigned renderErrored = 0;
     unsigned renderFailed = 0;
+    unsigned labelCutOffFound = 0;
 
     std::string errorMessage;
     double difference = 0.0;
diff --git a/render-test/parser.cpp b/render-test/parser.cpp
index e5c5a1edc9..4e2a1aa98c 100644
--- a/render-test/parser.cpp
+++ b/render-test/parser.cpp
@@ -43,6 +43,7 @@
 namespace {
 
 const char* resultsStyle = R"HTML(
+<meta charset="UTF-8">
 <style>
     body { font: 18px/1.2 -apple-system, BlinkMacSystemFont, "Helvetica Neue", Helvetica, Arial, sans-serif; padding: 10px; }
     h1 { font-size: 32px; margin-bottom: 0; }
@@ -1336,8 +1337,9 @@ std::string createResultItem(const TestMetadata& metadata, bool hasFailedTests)
         html.append("<p style=\"color: red\"><strong>Error:</strong> " + metadata.errorMessage + "</p>\n");
     }
 
-    if (metadata.metricsFailed || metadata.metricsErrored) {
-        html.append("<p style=\"color: red\"><strong>Error:</strong> " + metadata.errorMessage + "</p>\n");
+    if (metadata.metricsFailed || metadata.metricsErrored || metadata.labelCutOffFound) {
+        html.append("<p style=\"color: red\"><strong>Error:</strong> " +
+                    std::regex_replace(metadata.errorMessage, std::regex{"\n"}, "<br>") + "</p>\n");
     }
 
     if (metadata.difference != 0.0) {
diff --git a/render-test/render_test.cpp b/render-test/render_test.cpp
index c4ea7e64ab..a6a372d236 100644
--- a/render-test/render_test.cpp
+++ b/render-test/render_test.cpp
@@ -190,7 +190,7 @@ int runRenderTests(int argc, char** argv, std::function<void()> testStatus) {
             runner.run(metadata);
         }
 
-        bool errored = metadata.metricsErrored || metadata.renderErrored;
+        bool errored = metadata.metricsErrored || metadata.renderErrored || metadata.labelCutOffFound;
         bool passed = !errored && !metadata.metricsFailed && !metadata.renderFailed;
 
         if (shouldIgnore) {
diff --git a/render-test/runner.cpp b/render-test/runner.cpp
index de43e5ddd8..fe006f3a90 100644
--- a/render-test/runner.cpp
+++ b/render-test/runner.cpp
@@ -30,6 +30,9 @@
 #include <utility>
 #include <sstream>
 
+#include <codecvt>
+#include <locale>
+
 using namespace mbgl;
 using namespace TestOperationNames;
 
@@ -746,6 +749,9 @@ void TestRunner::run(TestMetadata& metadata) {
     auto camera = map.getStyle().getDefaultCamera();
 
     HeadlessFrontend::RenderResult result{};
+    std::string cutOffLabelsReport;
+    std::string duplicationsReport;
+    std::size_t duplicationsCount = 0u;
 
     if (metadata.mapMode == MapMode::Tile) {
         assert(camera.zoom);
@@ -754,6 +760,12 @@ void TestRunner::run(TestMetadata& metadata) {
         assert(!tileIds.empty());
         std::set<uint32_t> xDims;
         std::set<uint32_t> yDims;
+        struct SymbolLocationAndStatus {
+            UnwrappedTileID tileId;
+            mapbox::geometry::box<float> location;
+            bool placed;
+        };
+        std::map<std::u16string, std::vector<SymbolLocationAndStatus>> symbolIndex;
 
         for (const auto& tileId : tileIds) {
             xDims.insert(tileId.canonical.x);
@@ -766,6 +778,7 @@ void TestRunner::run(TestMetadata& metadata) {
             PremultipliedImage({uint32_t(xDims.size()) * tileScreenSize, uint32_t(yDims.size()) * tileScreenSize});
         for (const auto& tileId : tileIds) {
             resetContext(metadata, ctx);
+            ctx.getFrontend().getRenderer()->collectPlacedSymbolData(true);
             auto cameraForTile{camera};
             cameraForTile.withCenter(getTileCenterCoordinates(tileId));
             map.jumpTo(cameraForTile);
@@ -775,9 +788,49 @@ void TestRunner::run(TestMetadata& metadata) {
                 metadata.errorMessage = "Failed rendering tile: " + util::toString(tileId);
                 return;
             }
-
             auto xOffset = getImageTileOffset(xDims, tileId.canonical.x, metadata.pixelRatio);
             auto yOffset = getImageTileOffset(yDims, tileId.canonical.y, metadata.pixelRatio);
+
+            const auto& placedSymbols = ctx.getFrontend().getRenderer()->getPlacedSymbolsData();
+            for (const auto& placedSymbol : placedSymbols) {
+                if (placedSymbol.intersectsTileBorder) {
+                    if (placedSymbol.textCollisionBox) {
+                        mapbox::geometry::box<float> box = *placedSymbol.textCollisionBox;
+                        box.min.x += xOffset - placedSymbol.viewportPadding;
+                        box.max.x += xOffset - placedSymbol.viewportPadding;
+                        box.min.y += yOffset - placedSymbol.viewportPadding;
+                        box.max.y += yOffset - placedSymbol.viewportPadding;
+
+                        auto& symbols = symbolIndex[placedSymbol.key];
+                        auto it = std::find_if(symbols.begin(), symbols.end(), [box](const auto& a) {
+                            return a.location.min == box.min && a.location.max == box.max;
+                        });
+
+                        static std::wstring_convert<std::codecvt_utf8<char16_t>, char16_t> cv;
+                        if (it == symbols.end()) {
+                            symbols.push_back({tileId, box, placedSymbol.textPlaced});
+                        } else if (tileId == it->tileId) {
+                            std::stringstream ss;
+                            ss << std::endl
+                               << ++duplicationsCount << ". \"" << cv.to_bytes(placedSymbol.key) << "\" ((" << box.min.x
+                               << ", " << box.min.y << "), (" << box.max.x << ", " << box.max.y << ")) "
+                               << "at " << util::toString(tileId);
+                            duplicationsReport += ss.str();
+                            continue;
+                        } else if (it->placed != placedSymbol.textPlaced) {
+                            std::stringstream ss;
+                            ss << std::endl
+                               << ++metadata.labelCutOffFound << ". \"" << cv.to_bytes(placedSymbol.key) << "\" (("
+                               << box.min.x << ", " << box.min.y << "), (" << box.max.x << ", " << box.max.y << "))"
+                               << (placedSymbol.textPlaced ? " is placed at " : " is not placed at ")
+                               << util::toString(tileId) << " and" << (it->placed ? " placed at " : " not placed at ")
+                               << util::toString(it->tileId);
+                            cutOffLabelsReport += ss.str();
+                        }
+                    }
+                }
+            }
+
             PremultipliedImage::copy(
                 resultForTile.image, result.image, {0, 0}, {xOffset, yOffset}, resultForTile.image.size);
             result.stats += resultForTile.stats;
@@ -796,6 +849,14 @@ void TestRunner::run(TestMetadata& metadata) {
 
     if (metadata.renderTest) {
         checkProbingResults(metadata);
+        if (metadata.labelCutOffFound) { // Append label cut-off statistics.
+            metadata.errorMessage += "\n Label cut-offs:";
+            metadata.errorMessage += cutOffLabelsReport;
+            if (duplicationsCount) {
+                metadata.errorMessage += "\n\n Label duplications:";
+                metadata.errorMessage += duplicationsReport;
+            }
+        }
         checkRenderTestResults(std::move(result.image), metadata);
     } else {
         std::vector<mbgl::Feature> features;