12 files changed, 426 insertions, 130 deletions

diff --git a/src/mbgl/style/sources/geojson_source.cpp b/src/mbgl/style/sources/geojson_source.cpp
index 992f82b1e7..4e3478322d 100644
--- a/src/mbgl/style/sources/geojson_source.cpp
+++ b/src/mbgl/style/sources/geojson_source.cpp
@@ -1,27 +1,81 @@
 #include <mbgl/style/sources/geojson_source.hpp>
 #include <mbgl/style/sources/geojson_source_impl.hpp>
 #include <mbgl/style/source_observer.hpp>
+#include <mbgl/style/conversion/json.hpp>
+#include <mbgl/style/conversion/geojson.hpp>
+#include <mbgl/storage/file_source.hpp>
+#include <mbgl/util/logging.hpp>
 
 namespace mbgl {
 namespace style {
 
 GeoJSONSource::GeoJSONSource(const std::string& id, const GeoJSONOptions& options)
-    : Source(SourceType::GeoJSON,
-             std::make_unique<GeoJSONSource::Impl>(std::move(id), *this, options)),
-      impl(static_cast<Impl*>(baseImpl.get())) {
+    : Source(makeMutable<Impl>(std::move(id), options)) {
 }
 
-void GeoJSONSource::setURL(const std::string& url) {
-    impl->setURL(url);
+GeoJSONSource::~GeoJSONSource() = default;
+
+const GeoJSONSource::Impl& GeoJSONSource::impl() const {
+    return static_cast<const Impl&>(*baseImpl);
+}
+
+void GeoJSONSource::setURL(const std::string& url_) {
+    url = std::move(url_);
+
+    // Signal that the source description needs a reload
+    if (loaded || req) {
+        loaded = false;
+        req.reset();
+        observer->onSourceDescriptionChanged(*this);
+    }
 }
 
 void GeoJSONSource::setGeoJSON(const mapbox::geojson::geojson& geoJSON) {
-    impl->setGeoJSON(geoJSON);
-    impl->observer->onSourceChanged(*this);
+    req.reset();
+    baseImpl = makeMutable<Impl>(impl(), geoJSON);
+    observer->onSourceChanged(*this);
 }
 
 optional<std::string> GeoJSONSource::getURL() const {
-    return impl->getURL();
+    return url;
+}
+
+void GeoJSONSource::loadDescription(FileSource& fileSource) {
+    if (!url) {
+        loaded = true;
+        return;
+    }
+
+    if (req) {
+        return;
+    }
+
+    req = fileSource.request(Resource::source(*url), [this](Response res) {
+        if (res.error) {
+            observer->onSourceError(
+                *this, std::make_exception_ptr(std::runtime_error(res.error->message)));
+        } else if (res.notModified) {
+            return;
+        } else if (res.noContent) {
+            observer->onSourceError(
+                *this, std::make_exception_ptr(std::runtime_error("unexpectedly empty GeoJSON")));
+        } else {
+            conversion::Error error;
+            optional<GeoJSON> geoJSON = conversion::convertJSON<GeoJSON>(*res.data, error);
+            if (!geoJSON) {
+                Log::Error(Event::ParseStyle, "Failed to parse GeoJSON data: %s",
+                           error.message.c_str());
+                // Create an empty GeoJSON VT object to make sure we're not infinitely waiting for
+                // tiles to load.
+                baseImpl = makeMutable<Impl>(impl(), GeoJSON{ FeatureCollection{} });
+            } else {
+                baseImpl = makeMutable<Impl>(impl(), *geoJSON);
+            }
+
+            loaded = true;
+            observer->onSourceLoaded(*this);
+        }
+    });
 }
 
 } // namespace style
diff --git a/src/mbgl/style/sources/geojson_source_impl.cpp b/src/mbgl/style/sources/geojson_source_impl.cpp
index 1a686ff9bc..efa4018b46 100644
--- a/src/mbgl/style/sources/geojson_source_impl.cpp
+++ b/src/mbgl/style/sources/geojson_source_impl.cpp
@@ -1,16 +1,13 @@
 #include <mbgl/style/sources/geojson_source_impl.hpp>
-#include <mbgl/style/conversion/json.hpp>
-#include <mbgl/style/conversion/geojson.hpp>
-#include <mbgl/style/source_observer.hpp>
+#include <mbgl/util/constants.hpp>
 #include <mbgl/tile/tile_id.hpp>
-#include <mbgl/storage/file_source.hpp>
-#include <mbgl/renderer/sources/render_geojson_source.hpp>
-#include <mbgl/util/constants.cpp>
-#include <mbgl/util/logging.hpp>
+#include <mbgl/util/string.hpp>
 
 #include <mapbox/geojsonvt.hpp>
 #include <supercluster.hpp>
 
+#include <cmath>
+
 namespace mbgl {
 namespace style {
 
@@ -42,33 +39,14 @@ private:
     mapbox::supercluster::Supercluster impl;
 };
 
-GeoJSONSource::Impl::Impl(std::string id_, Source& base_, const GeoJSONOptions options_)
-    : Source::Impl(SourceType::GeoJSON, std::move(id_), base_), options(options_) {
-}
-
-GeoJSONSource::Impl::~Impl() = default;
-
-void GeoJSONSource::Impl::setURL(std::string url_) {
-    url = std::move(url_);
-
-    // Signal that the source description needs a reload
-    if (loaded || req) {
-        loaded = false;
-        req.reset();
-        observer->onSourceDescriptionChanged(base);
-    }
-}
-
-optional<std::string> GeoJSONSource::Impl::getURL() const {
-    return url;
-}
-
-void GeoJSONSource::Impl::setGeoJSON(const GeoJSON& geoJSON) {
-    req.reset();
-    _setGeoJSON(geoJSON);
+GeoJSONSource::Impl::Impl(std::string id_, GeoJSONOptions options_)
+    : Source::Impl(SourceType::GeoJSON, std::move(id_)),
+      options(std::move(options_)) {
 }
 
-void GeoJSONSource::Impl::_setGeoJSON(const GeoJSON& geoJSON) {
+GeoJSONSource::Impl::Impl(const Impl& other, const GeoJSON& geoJSON)
+    : Source::Impl(other),
+      options(other.options) {
     double scale = util::EXTENT / util::tileSize;
 
     if (options.cluster
@@ -77,60 +55,20 @@ void GeoJSONSource::Impl::_setGeoJSON(const GeoJSON& geoJSON) {
         mapbox::supercluster::Options clusterOptions;
         clusterOptions.maxZoom = options.clusterMaxZoom;
         clusterOptions.extent = util::EXTENT;
-        clusterOptions.radius = std::round(scale * options.clusterRadius);
+        clusterOptions.radius = ::round(scale * options.clusterRadius);
         data = std::make_unique<SuperclusterData>(
             geoJSON.get<mapbox::geometry::feature_collection<double>>(), clusterOptions);
     } else {
         mapbox::geojsonvt::Options vtOptions;
         vtOptions.maxZoom = options.maxzoom;
         vtOptions.extent = util::EXTENT;
-        vtOptions.buffer = std::round(scale * options.buffer);
+        vtOptions.buffer = ::round(scale * options.buffer);
         vtOptions.tolerance = scale * options.tolerance;
         data = std::make_unique<GeoJSONVTData>(geoJSON, vtOptions);
     }
 }
 
-void GeoJSONSource::Impl::loadDescription(FileSource& fileSource) {
-    if (!url) {
-        loaded = true;
-        return;
-    }
-
-    if (req) {
-        return;
-    }
-
-    req = fileSource.request(Resource::source(*url), [this](Response res) {
-        if (res.error) {
-            observer->onSourceError(
-                base, std::make_exception_ptr(std::runtime_error(res.error->message)));
-        } else if (res.notModified) {
-            return;
-        } else if (res.noContent) {
-            observer->onSourceError(
-                base, std::make_exception_ptr(std::runtime_error("unexpectedly empty GeoJSON")));
-        } else {
-            conversion::Error error;
-            optional<GeoJSON> geoJSON = conversion::convertJSON<GeoJSON>(*res.data, error);
-            if (!geoJSON) {
-                Log::Error(Event::ParseStyle, "Failed to parse GeoJSON data: %s",
-                           error.message.c_str());
-                // Create an empty GeoJSON VT object to make sure we're not infinitely waiting for
-                // tiles to load.
-                _setGeoJSON(GeoJSON{ FeatureCollection{} });
-            } else {
-                _setGeoJSON(*geoJSON);
-            }
-
-            loaded = true;
-            observer->onSourceLoaded(base);
-        }
-    });
-}
-
-std::unique_ptr<RenderSource> GeoJSONSource::Impl::createRenderSource() const {
-    return std::make_unique<RenderGeoJSONSource>(*this);
-}
+GeoJSONSource::Impl::~Impl() = default;
 
 Range<uint8_t> GeoJSONSource::Impl::getZoomRange() const {
     return { 0, options.maxzoom };
@@ -140,5 +78,9 @@ GeoJSONData* GeoJSONSource::Impl::getData() const {
     return data.get();
 }
 
+optional<std::string> GeoJSONSource::Impl::getAttribution() const {
+    return {};
+}
+
 } // namespace style
 } // namespace mbgl
diff --git a/src/mbgl/style/sources/geojson_source_impl.hpp b/src/mbgl/style/sources/geojson_source_impl.hpp
index dece1269f8..a524bab9f2 100644
--- a/src/mbgl/style/sources/geojson_source_impl.hpp
+++ b/src/mbgl/style/sources/geojson_source_impl.hpp
@@ -2,7 +2,7 @@
 
 #include <mbgl/style/source_impl.hpp>
 #include <mbgl/style/sources/geojson_source.hpp>
-#include <mbgl/util/variant.hpp>
+#include <mbgl/util/range.hpp>
 
 namespace mbgl {
 
@@ -19,25 +19,17 @@ public:
 
 class GeoJSONSource::Impl : public Source::Impl {
 public:
-    Impl(std::string id, Source&, const GeoJSONOptions);
+    Impl(std::string id, GeoJSONOptions);
+    Impl(const GeoJSONSource::Impl&, const GeoJSON&);
     ~Impl() final;
 
-    void setURL(std::string);
-    optional<std::string> getURL() const;
     Range<uint8_t> getZoomRange() const;
-
-    void setGeoJSON(const GeoJSON&);
     GeoJSONData* getData() const;
 
-    void loadDescription(FileSource&) final;
-    std::unique_ptr<RenderSource> createRenderSource() const final;
+    optional<std::string> getAttribution() const final;
 
 private:
-    void _setGeoJSON(const GeoJSON&);
-
     GeoJSONOptions options;
-    optional<std::string> url;
-    std::unique_ptr<AsyncRequest> req;
     std::unique_ptr<GeoJSONData> data;
 };
 
diff --git a/src/mbgl/style/sources/image_source.cpp b/src/mbgl/style/sources/image_source.cpp
new file mode 100644
index 0000000000..9b60ba1a48
--- /dev/null
+++ b/src/mbgl/style/sources/image_source.cpp
@@ -0,0 +1,84 @@
+#include <mbgl/style/sources/image_source.hpp>
+#include <mbgl/style/sources/image_source_impl.hpp>
+#include <mbgl/util/geo.hpp>
+#include <mbgl/style/source_observer.hpp>
+#include <mbgl/util/premultiply.hpp>
+#include <mbgl/storage/file_source.hpp>
+
+namespace mbgl {
+namespace style {
+
+ImageSource::ImageSource(std::string id, const std::array<LatLng, 4> coords_)
+    : Source(makeMutable<Impl>(std::move(id), coords_)) {
+}
+
+ImageSource::~ImageSource() = default;
+
+const ImageSource::Impl& ImageSource::impl() const {
+    return static_cast<const Impl&>(*baseImpl);
+}
+
+void ImageSource::setCoordinates(const std::array<LatLng, 4>& coords_) {
+    baseImpl = makeMutable<Impl>(impl(), coords_);
+    observer->onSourceChanged(*this);
+}
+
+std::array<LatLng, 4> ImageSource::getCoordinates() const {
+    return impl().getCoordinates();
+}
+
+void ImageSource::setURL(const std::string& url_) {
+    url = std::move(url_);
+    // Signal that the source description needs a reload
+    if (loaded || req) {
+        loaded = false;
+        req.reset();
+        observer->onSourceDescriptionChanged(*this);
+    }
+}
+
+void ImageSource::setImage(PremultipliedImage&& image_) {
+    url = {};
+    if (req) {
+        req.reset();
+    }
+    loaded = true;
+    baseImpl = makeMutable<Impl>(impl(), std::move(image_));
+    observer->onSourceChanged(*this);
+}
+
+optional<std::string> ImageSource::getURL() const {
+    return url;
+}
+
+void ImageSource::loadDescription(FileSource& fileSource) {
+    if (!url) {
+        loaded = true;
+    }
+
+    if (req ||  loaded) {
+        return;
+    }
+    const Resource imageResource { Resource::Image, *url, {}, Resource::Necessity::Required };
+
+    req = fileSource.request(imageResource, [this](Response res) {
+        if (res.error) {
+            observer->onSourceError(*this, std::make_exception_ptr(std::runtime_error(res.error->message)));
+        } else if (res.notModified) {
+            return;
+        } else if (res.noContent) {
+            observer->onSourceError(*this, std::make_exception_ptr(std::runtime_error("unexpectedly empty image url")));
+        } else {
+            try {
+                baseImpl = makeMutable<Impl>(impl(), decodeImage(*res.data));
+            } catch (...) {
+                observer->onSourceError(*this, std::current_exception());
+            }
+            loaded = true;
+            observer->onSourceLoaded(*this);
+        }
+    });
+}
+
+} // namespace style
+} // namespace mbgl
diff --git a/src/mbgl/style/sources/image_source_impl.cpp b/src/mbgl/style/sources/image_source_impl.cpp
new file mode 100644
index 0000000000..c1f31dbdc6
--- /dev/null
+++ b/src/mbgl/style/sources/image_source_impl.cpp
@@ -0,0 +1,38 @@
+#include <mbgl/style/sources/image_source_impl.hpp>
+#include <mbgl/util/geo.hpp>
+
+namespace mbgl {
+namespace style {
+
+ImageSource::Impl::Impl(std::string id_, std::array<LatLng, 4> coords_)
+    : Source::Impl(SourceType::Image, std::move(id_)),
+    coords(std::move(coords_)) {
+}
+
+ImageSource::Impl::Impl(const Impl& other, std::array<LatLng, 4> coords_)
+    : Source::Impl(other),
+    coords(std::move(coords_)),
+    image(other.image) {
+}
+
+ImageSource::Impl::Impl(const Impl& rhs, PremultipliedImage&& image_)
+    : Source::Impl(rhs),
+    coords(rhs.coords),
+    image(std::make_shared<PremultipliedImage>(std::move(image_))) {
+}
+ImageSource::Impl::~Impl() = default;
+
+std::shared_ptr<PremultipliedImage> ImageSource::Impl::getImage() const {
+    return image;
+}
+
+std::array<LatLng, 4> ImageSource::Impl::getCoordinates() const {
+    return coords;
+}
+
+optional<std::string> ImageSource::Impl::getAttribution() const {
+    return {};
+}
+
+} // namespace style
+} // namespace mbgl
diff --git a/src/mbgl/style/sources/image_source_impl.hpp b/src/mbgl/style/sources/image_source_impl.hpp
new file mode 100644
index 0000000000..1e1b005a32
--- /dev/null
+++ b/src/mbgl/style/sources/image_source_impl.hpp
@@ -0,0 +1,30 @@
+#pragma once
+
+#include <mbgl/style/source_impl.hpp>
+#include <mbgl/style/sources/image_source.hpp>
+#include <mbgl/util/image.hpp>
+#include <mbgl/util/geo.hpp>
+
+namespace mbgl {
+
+namespace style {
+
+class ImageSource::Impl : public Source::Impl {
+public:
+    Impl(std::string id, std::array<LatLng, 4> coords);
+    Impl(const Impl& rhs, std::array<LatLng, 4> coords);
+    Impl(const Impl& rhs, PremultipliedImage&& image);
+
+    ~Impl() final;
+
+    std::shared_ptr<PremultipliedImage> getImage() const;
+    std::array<LatLng, 4> getCoordinates() const;
+
+    optional<std::string> getAttribution() const final;
+private:
+    std::array<LatLng, 4> coords;
+    std::shared_ptr<PremultipliedImage> image;
+};
+
+} // namespace style
+} // namespace mbgl
diff --git a/src/mbgl/style/sources/raster_source.cpp b/src/mbgl/style/sources/raster_source.cpp
index 94fdbcef12..0a0412a4ed 100644
--- a/src/mbgl/style/sources/raster_source.cpp
+++ b/src/mbgl/style/sources/raster_source.cpp
@@ -1,21 +1,81 @@
 #include <mbgl/style/sources/raster_source.hpp>
 #include <mbgl/style/sources/raster_source_impl.hpp>
+#include <mbgl/style/source_observer.hpp>
+#include <mbgl/style/conversion/json.hpp>
+#include <mbgl/style/conversion/tileset.hpp>
+#include <mbgl/storage/file_source.hpp>
+#include <mbgl/util/mapbox.hpp>
 
 namespace mbgl {
 namespace style {
 
-RasterSource::RasterSource(std::string id, variant<std::string, Tileset> urlOrTileset, uint16_t tileSize)
-    : Source(SourceType::Raster, std::make_unique<RasterSource::Impl>(std::move(id), *this, std::move(urlOrTileset), tileSize)),
-      impl(static_cast<Impl*>(baseImpl.get())) {
+RasterSource::RasterSource(std::string id, variant<std::string, Tileset> urlOrTileset_, uint16_t tileSize)
+    : Source(makeMutable<Impl>(std::move(id), tileSize)),
+      urlOrTileset(std::move(urlOrTileset_)) {
+}
+
+RasterSource::~RasterSource() = default;
+
+const RasterSource::Impl& RasterSource::impl() const {
+    return static_cast<const Impl&>(*baseImpl);
+}
+
+const variant<std::string, Tileset>& RasterSource::getURLOrTileset() const {
+    return urlOrTileset;
 }
 
 optional<std::string> RasterSource::getURL() const {
-    auto urlOrTileset = impl->getURLOrTileset();
-    if (urlOrTileset.is<std::string>()) {
-        return urlOrTileset.get<std::string>();
-    } else {
+    if (urlOrTileset.is<Tileset>()) {
         return {};
     }
+
+    return urlOrTileset.get<std::string>();
+}
+
+uint16_t RasterSource::getTileSize() const {
+    return impl().getTileSize();
+}
+
+void RasterSource::loadDescription(FileSource& fileSource) {
+    if (urlOrTileset.is<Tileset>()) {
+        baseImpl = makeMutable<Impl>(impl(), urlOrTileset.get<Tileset>());
+        loaded = true;
+        return;
+    }
+
+    if (req) {
+        return;
+    }
+
+    const std::string& url = urlOrTileset.get<std::string>();
+    req = fileSource.request(Resource::source(url), [this, url](Response res) {
+        if (res.error) {
+            observer->onSourceError(*this, std::make_exception_ptr(std::runtime_error(res.error->message)));
+        } else if (res.notModified) {
+            return;
+        } else if (res.noContent) {
+            observer->onSourceError(*this, std::make_exception_ptr(std::runtime_error("unexpectedly empty TileJSON")));
+        } else {
+            conversion::Error error;
+            optional<Tileset> tileset = conversion::convertJSON<Tileset>(*res.data, error);
+            if (!tileset) {
+                observer->onSourceError(*this, std::make_exception_ptr(std::runtime_error(error.message)));
+                return;
+            }
+
+            util::mapbox::canonicalizeTileset(*tileset, url, getType(), getTileSize());
+            bool changed = impl().getTileset() != *tileset;
+
+            baseImpl = makeMutable<Impl>(impl(), *tileset);
+            loaded = true;
+
+            observer->onSourceLoaded(*this);
+
+            if (changed) {
+                observer->onSourceChanged(*this);
+            }
+        }
+    });
 }
 
 } // namespace style
diff --git a/src/mbgl/style/sources/raster_source_impl.cpp b/src/mbgl/style/sources/raster_source_impl.cpp
index b85d221f2e..50dae1f07e 100644
--- a/src/mbgl/style/sources/raster_source_impl.cpp
+++ b/src/mbgl/style/sources/raster_source_impl.cpp
@@ -1,17 +1,32 @@
 #include <mbgl/style/sources/raster_source_impl.hpp>
-#include <mbgl/renderer/sources/render_raster_source.hpp>
 
 namespace mbgl {
 namespace style {
 
-RasterSource::Impl::Impl(std::string id_, Source& base_,
-                         variant<std::string, Tileset> urlOrTileset_,
-                         uint16_t tileSize_)
-    : TileSourceImpl(SourceType::Raster, std::move(id_), base_, std::move(urlOrTileset_), tileSize_) {
+RasterSource::Impl::Impl(std::string id_, uint16_t tileSize_)
+    : Source::Impl(SourceType::Raster, std::move(id_)),
+      tileSize(tileSize_) {
 }
 
-std::unique_ptr<RenderSource> RasterSource::Impl::createRenderSource() const {
-    return std::make_unique<RenderRasterSource>(*this);
+RasterSource::Impl::Impl(const Impl& other, Tileset tileset_)
+    : Source::Impl(other),
+      tileSize(other.tileSize),
+      tileset(std::move(tileset_)) {
+}
+
+uint16_t RasterSource::Impl::getTileSize() const {
+    return tileSize;
+}
+
+optional<Tileset> RasterSource::Impl::getTileset() const {
+    return tileset;
+}
+
+optional<std::string> RasterSource::Impl::getAttribution() const {
+    if (!tileset) {
+        return {};
+    }
+    return tileset->attribution;
 }
 
 } // namespace style
diff --git a/src/mbgl/style/sources/raster_source_impl.hpp b/src/mbgl/style/sources/raster_source_impl.hpp
index 4bc76560f8..c41d5485b2 100644
--- a/src/mbgl/style/sources/raster_source_impl.hpp
+++ b/src/mbgl/style/sources/raster_source_impl.hpp
@@ -1,16 +1,24 @@
 #pragma once
 
 #include <mbgl/style/sources/raster_source.hpp>
-#include <mbgl/style/tile_source_impl.hpp>
+#include <mbgl/style/source_impl.hpp>
 
 namespace mbgl {
 namespace style {
 
-class RasterSource::Impl : public TileSourceImpl {
+class RasterSource::Impl : public Source::Impl {
 public:
-    Impl(std::string id, Source&, variant<std::string, Tileset>, uint16_t tileSize);
+    Impl(std::string id, uint16_t tileSize);
+    Impl(const Impl&, Tileset);
 
-    std::unique_ptr<RenderSource> createRenderSource() const final;
+    optional<Tileset> getTileset() const;
+    uint16_t getTileSize() const;
+
+    optional<std::string> getAttribution() const final;
+
+private:
+    uint16_t tileSize;
+    optional<Tileset> tileset;
 };
 
 } // namespace style
diff --git a/src/mbgl/style/sources/vector_source.cpp b/src/mbgl/style/sources/vector_source.cpp
index 4bcd3b8985..ccdd453c75 100644
--- a/src/mbgl/style/sources/vector_source.cpp
+++ b/src/mbgl/style/sources/vector_source.cpp
@@ -1,21 +1,78 @@
 #include <mbgl/style/sources/vector_source.hpp>
 #include <mbgl/style/sources/vector_source_impl.hpp>
+#include <mbgl/style/source_observer.hpp>
+#include <mbgl/style/conversion/json.hpp>
+#include <mbgl/style/conversion/tileset.hpp>
+#include <mbgl/storage/file_source.hpp>
+#include <mbgl/util/mapbox.hpp>
+#include <mbgl/util/constants.hpp>
 
 namespace mbgl {
 namespace style {
 
-VectorSource::VectorSource(std::string id, variant<std::string, Tileset> urlOrTileset)
-    : Source(SourceType::Vector, std::make_unique<VectorSource::Impl>(std::move(id), *this, std::move(urlOrTileset))),
-      impl(static_cast<Impl*>(baseImpl.get())) {
+VectorSource::VectorSource(std::string id, variant<std::string, Tileset> urlOrTileset_)
+    : Source(makeMutable<Impl>(std::move(id))),
+      urlOrTileset(std::move(urlOrTileset_)) {
+}
+
+VectorSource::~VectorSource() = default;
+
+const VectorSource::Impl& VectorSource::impl() const {
+    return static_cast<const Impl&>(*baseImpl);
+}
+
+const variant<std::string, Tileset>& VectorSource::getURLOrTileset() const {
+    return urlOrTileset;
 }
 
 optional<std::string> VectorSource::getURL() const {
-    auto urlOrTileset = impl->getURLOrTileset();
-    if (urlOrTileset.is<std::string>()) {
-        return urlOrTileset.get<std::string>();
-    } else {
+    if (urlOrTileset.is<Tileset>()) {
         return {};
     }
+
+    return urlOrTileset.get<std::string>();
+}
+
+void VectorSource::loadDescription(FileSource& fileSource) {
+    if (urlOrTileset.is<Tileset>()) {
+        baseImpl = makeMutable<Impl>(impl(), urlOrTileset.get<Tileset>());
+        loaded = true;
+        return;
+    }
+
+    if (req) {
+        return;
+    }
+
+    const std::string& url = urlOrTileset.get<std::string>();
+    req = fileSource.request(Resource::source(url), [this, url](Response res) {
+        if (res.error) {
+            observer->onSourceError(*this, std::make_exception_ptr(std::runtime_error(res.error->message)));
+        } else if (res.notModified) {
+            return;
+        } else if (res.noContent) {
+            observer->onSourceError(*this, std::make_exception_ptr(std::runtime_error("unexpectedly empty TileJSON")));
+        } else {
+            conversion::Error error;
+            optional<Tileset> tileset = conversion::convertJSON<Tileset>(*res.data, error);
+            if (!tileset) {
+                observer->onSourceError(*this, std::make_exception_ptr(std::runtime_error(error.message)));
+                return;
+            }
+
+            util::mapbox::canonicalizeTileset(*tileset, url, getType(), util::tileSize);
+            bool changed = impl().getTileset() != *tileset;
+
+            baseImpl = makeMutable<Impl>(impl(), *tileset);
+            loaded = true;
+
+            observer->onSourceLoaded(*this);
+
+            if (changed) {
+                observer->onSourceChanged(*this);
+            }
+        }
+    });
 }
 
 } // namespace style
diff --git a/src/mbgl/style/sources/vector_source_impl.cpp b/src/mbgl/style/sources/vector_source_impl.cpp
index 158abf8575..b06f0557bf 100644
--- a/src/mbgl/style/sources/vector_source_impl.cpp
+++ b/src/mbgl/style/sources/vector_source_impl.cpp
@@ -1,16 +1,26 @@
 #include <mbgl/style/sources/vector_source_impl.hpp>
-#include <mbgl/renderer/sources/render_vector_source.hpp>
-#include <mbgl/util/constants.hpp>
 
 namespace mbgl {
 namespace style {
 
-VectorSource::Impl::Impl(std::string id_, Source& base_, variant<std::string, Tileset> urlOrTileset_)
-    : TileSourceImpl(SourceType::Vector, std::move(id_), base_, std::move(urlOrTileset_), util::tileSize) {
+VectorSource::Impl::Impl(std::string id_)
+    : Source::Impl(SourceType::Vector, std::move(id_)) {
 }
 
-std::unique_ptr<RenderSource> VectorSource::Impl::createRenderSource() const {
-    return std::make_unique<RenderVectorSource>(*this);
+VectorSource::Impl::Impl(const Impl& other, Tileset tileset_)
+    : Source::Impl(other),
+      tileset(std::move(tileset_)) {
+}
+
+optional<Tileset> VectorSource::Impl::getTileset() const {
+    return tileset;
+}
+
+optional<std::string> VectorSource::Impl::getAttribution() const {
+    if (!tileset) {
+        return {};
+    }
+    return tileset->attribution;
 }
 
 } // namespace style
diff --git a/src/mbgl/style/sources/vector_source_impl.hpp b/src/mbgl/style/sources/vector_source_impl.hpp
index 844739948c..5e559b9266 100644
--- a/src/mbgl/style/sources/vector_source_impl.hpp
+++ b/src/mbgl/style/sources/vector_source_impl.hpp
@@ -1,16 +1,22 @@
 #pragma once
 
 #include <mbgl/style/sources/vector_source.hpp>
-#include <mbgl/style/tile_source_impl.hpp>
+#include <mbgl/style/source_impl.hpp>
 
 namespace mbgl {
 namespace style {
 
-class VectorSource::Impl : public TileSourceImpl {
+class VectorSource::Impl : public Source::Impl {
 public:
-    Impl(std::string id, Source&, variant<std::string, Tileset>);
+    Impl(std::string id);
+    Impl(const Impl&, Tileset);
 
-    std::unique_ptr<RenderSource> createRenderSource() const final;
+    optional<Tileset> getTileset() const;
+
+    optional<std::string> getAttribution() const final;
+
+private:
+    optional<Tileset> tileset;
 };
 
 } // namespace style