Add a test that GDAL plugin does not upsample

test/unit/datasource/gdal.cpp

@@ -0,0 +1,89 @@
+/*****************************************************************************
+ *
+ * This file is part of Mapnik (c++ mapping toolkit)
+ *
+ * Copyright (C) 2015 Artem Pavlenko
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ *****************************************************************************/
+
+#include "catch.hpp"
+
+#include <mapnik/datasource.hpp>
+#include <mapnik/datasource_cache.hpp>
+#include <mapnik/raster.hpp>
+#include <mapnik/util/fs.hpp>
+
+namespace {
+
+mapnik::datasource_ptr get_gdal_ds(std::string const& file_name,
+                                   boost::optional<mapnik::value_integer> band)
+{
+    std::string gdal_plugin("./plugins/input/gdal.input");
+    if (!mapnik::util::exists(gdal_plugin))
+    {
+        return mapnik::datasource_ptr();
+    }
+
+    mapnik::parameters params;
+    params["type"] = std::string("gdal");
+    params["file"] = file_name;
+    if (band)
+    {
+        params["band"] = *band;
+    }
+
+    auto ds = mapnik::datasource_cache::instance().create(params);
+    REQUIRE(ds != nullptr);
+
+    return ds;
+}
+
+} // anonymous namespace
+
+TEST_CASE("gdal") {
+
+    SECTION("upsampling")
+    {
+        std::string dataset = "test/data/tiff/ndvi_256x256_gray32f_tiled.tif";
+        mapnik::datasource_ptr ds = get_gdal_ds(dataset, 1);
+
+        if (!ds)
+        {
+            // GDAL plugin not built.
+            return;
+        }
+
+        mapnik::box2d<double> envelope = ds->envelope();
+        CHECK(envelope.width() == 256);
+        CHECK(envelope.height() == 256);
+
+        // Indicate four times bigger resolution.
+        mapnik::query::resolution_type resolution(2.0, 2.0);
+        mapnik::query query(envelope, resolution, 1.0);
+
+        auto features = ds->features(query);
+        auto feature = features->next();
+
+        mapnik::raster_ptr raster = feature->get_raster();
+        REQUIRE(raster != nullptr);
+
+        // Check whether result is not scaled up.
+        CHECK(raster->data_.width() == 256);
+        CHECK(raster->data_.height() == 256);
+    }
+
+} // END TEST CASE