[test] Re-added API.ZoomHistory

cmake/test-files.cmake

@@ -18,6 +18,7 @@ set(MBGL_TEST_FILES
     test/api/custom_layer.test.cpp
     test/api/query.test.cpp
     test/api/recycle_map.cpp
+    test/api/zoom_history.cpp
 
     # gl
     test/gl/bucket.test.cpp

test/api/zoom_history.cpp

@@ -0,0 +1,65 @@
+#include <mbgl/test/util.hpp>
+#include <mbgl/test/stub_file_source.hpp>
+
+#include <mbgl/gl/headless_frontend.hpp>
+#include <mbgl/map/map.hpp>
+#include <mbgl/renderer/backend_scope.hpp>
+#include <mbgl/storage/online_file_source.hpp>
+#include <mbgl/style/function/camera_function.hpp>
+#include <mbgl/style/function/exponential_stops.hpp>
+#include <mbgl/style/image.hpp>
+#include <mbgl/style/layers/line_layer.hpp>
+#include <mbgl/style/sources/geojson_source.hpp>
+#include <mbgl/style/style.hpp>
+#include <mbgl/util/default_thread_pool.hpp>
+#include <mbgl/util/exception.hpp>
+#include <mbgl/util/geometry.hpp>
+#include <mbgl/util/geojson.hpp>
+#include <mbgl/util/io.hpp>
+#include <mbgl/util/run_loop.hpp>
+
+using namespace mbgl;
+using namespace mbgl::style;
+
+TEST(API, ZoomHistory) {
+    util::RunLoop loop;
+
+    StubFileSource fileSource;
+    ThreadPool threadPool(4);
+    float pixelRatio { 1 };
+
+    HeadlessFrontend frontend { pixelRatio, fileSource, threadPool };
+    auto map = std::make_unique<Map>(frontend, MapObserver::nullObserver(), frontend.getSize(),
+                                     pixelRatio, fileSource, threadPool, MapMode::Still);
+
+    EXPECT_TRUE(map);
+
+    map->getStyle().loadJSON(util::read_file("test/fixtures/api/empty.json"));
+
+    auto source = std::make_unique<GeoJSONSource>("source");
+    source->setGeoJSON({ LineString<double> { { 45, -45 }, { -45, 45 } } });
+    map->getStyle().addSource(std::move(source));
+
+    auto layer = std::make_unique<LineLayer>("layer-1", "source");
+    layer->setLineWidth(CameraFunction<float> { ExponentialStops<float> {{ { 0, 8 }, { 1, 16 } }} });
+    layer->setLineDasharray({ std::vector<float> { 1, 1 } });
+    layer->setLineColor( { Color::black() } );
+    map->getStyle().addLayer(std::move(layer));
+
+    layer = std::make_unique<LineLayer>("layer-2", "source");
+    layer->setLineWidth(CameraFunction<float> { ExponentialStops<float> {{ { 0, 4 }, { 1, 8 } }} });
+    layer->setLineDasharray({ std::vector<float> { 2, 2 } });
+    layer->setLineColor( { Color::red() } );
+    map->getStyle().addLayer(std::move(layer));
+
+    // ZoomHistory.lastIntegerZoom is 1.
+    map->setZoom(1.0);
+    frontend.render(*map);
+
+    map->setZoom(0.0);
+    frontend.render(*map);
+
+    // ZoomHistory.lastIntegerZoom should be 0.
+    map->setZoom(0.5);
+    test::checkImage("test/fixtures/zoom_history", frontend.render(*map), 0.0002);
+}