[core] Add ImageSource support to style parsers

2 files changed, 85 insertions, 0 deletions

diff --git a/include/mbgl/style/conversion/coordinate.hpp b/include/mbgl/style/conversion/coordinate.hpp
new file mode 100644
index 0000000000..0adbb9a7ee
--- /dev/null
+++ b/include/mbgl/style/conversion/coordinate.hpp
@@ -0,0 +1,37 @@
+#pragma once
+
+#include <mbgl/style/conversion.hpp>
+#include <mbgl/util/geo.hpp>
+
+namespace mbgl {
+namespace style {
+namespace conversion {
+            
+template<>
+struct Converter<std::unique_ptr<LatLng>> {
+public:
+    template <class V>
+    optional<std::unique_ptr<LatLng>> operator() (const V& value, Error& error) const {
+        if (!isArray(value) || arrayLength(value) < 2 ) {
+            error = { "coordinate array must contain numeric longtitude and latitude values" };
+            return {};
+        }
+        //Style spec uses GeoJSON convention for specifying coordinates
+        optional<float> latitude = toNumber(arrayMember(value, 1));
+        optional<float> longitude = toNumber(arrayMember(value, 0));
+    
+        if (!latitude || !longitude) {
+            error = { "coordinate array must contain numeric longtitude and latitude values" };
+            return {};
+        }
+        if (*latitude < -90 || *latitude > 90 ){
+            error = { "coordinate latitude must be between -90 and 90" };
+            return {};
+        }
+        return { std::make_unique<LatLng>(*latitude, *longitude) };
+    }
+};
+
+} // namespace conversion
+} // namespace style
+} // namespace mbgl
diff --git a/include/mbgl/style/conversion/source.hpp b/include/mbgl/style/conversion/source.hpp
index dc7cdc0d42..e121e36955 100644
--- a/include/mbgl/style/conversion/source.hpp
+++ b/include/mbgl/style/conversion/source.hpp
@@ -1,6 +1,7 @@
 #pragma once
 
 #include <mbgl/style/conversion.hpp>
+#include <mbgl/style/conversion/coordinate.hpp>
 #include <mbgl/style/conversion/geojson.hpp>
 #include <mbgl/style/conversion/geojson_options.hpp>
 #include <mbgl/style/conversion/tileset.hpp>
@@ -8,6 +9,8 @@
 #include <mbgl/style/sources/geojson_source.hpp>
 #include <mbgl/style/sources/raster_source.hpp>
 #include <mbgl/style/sources/vector_source.hpp>
+#include <mbgl/style/sources/image_source.hpp>
+#include <mbgl/util/geo.hpp>
 
 namespace mbgl {
 namespace style {
@@ -16,6 +19,7 @@ namespace conversion {
 template <>
 struct Converter<std::unique_ptr<Source>> {
 public:
+    
     template <class V>
     optional<std::unique_ptr<Source>> operator()(const V& value, Error& error, const std::string& id) const {
         if (!isObject(value)) {
@@ -41,6 +45,8 @@ public:
             return convertVectorSource(id, value, error);
         } else if (*type == "geojson") {
             return convertGeoJSONSource(id, value, error);
+        } else if (*type == "image") {
+            return convertImageSource(id, value, error);
         } else {
             error = { "invalid source type" };
             return {};
@@ -136,6 +142,48 @@ private:
 
         return { std::move(result) };
     }
+    
+    template <class V>
+    optional<std::unique_ptr<Source>> convertImageSource(const std::string& id,
+                                                        const V& value,
+                                                        Error& error) const {
+        auto urlValue = objectMember(value, "url");
+        if (!urlValue) {
+            error = { "Image source must have a url value" };
+            return {};
+        }
+        
+        auto urlString = toString(*urlValue);
+        if (!urlString) {
+            error = { "Image url must be a URL string" };
+            return {};
+        }
+        
+        auto coordinatesValue = objectMember(value, "coordinates");
+        if (!coordinatesValue) {
+            error = { "Image source must have a coordinates values" };
+            return {};
+        }
+        
+        if (!isArray(*coordinatesValue) || arrayLength(*coordinatesValue) != 4) {
+            error = { "Image coordinates must be an array of four longitude latitude pairs" };
+            return {};
+        }
+        
+        std::vector<LatLng> coordinates;
+        coordinates.reserve(4);
+        for( std::size_t i=0; i < arrayLength(*coordinatesValue); i++) {
+            auto latLng = conversion::convert<LatLng>(arrayMember(*coordinatesValue,i), error);
+            if (!latLng) {
+                return {};
+            }
+            coordinates.push_back(*latLng);
+        }
+        auto result = std::make_unique<ImageSource>(id, coordinates);
+        result->setURL(*urlString);
+
+        return { std::move(result) };
+    }
 };
 
 } // namespace conversion