[core] Always request 1x and @2x sprite images for portability

When creating a offline region, we've previously only requested the sprite image for the specified resolution. This lead to offline packs not being usable on devices that have a different pixel ratio. We're now requesting both 1x and 2x sprites. Some devices use even higher or fractional pixel ratios. However, we only ever use 1x and 2x sprite images in our requests.

platform/default/mbgl/storage/offline_download.cpp

@@ -209,7 +209,7 @@ OfflineRegionStatus OfflineDownload::getStatus() const {
     }
 
     if (!parser.spriteURL.empty()) {
-        result->requiredResourceCount += 2;
+        result->requiredResourceCount += 4;
     }
 
     return *result;
@@ -306,9 +306,11 @@ void OfflineDownload::activateDownload() {
         }
 
         if (!parser.spriteURL.empty()) {
-            auto pixelRatio = definition.match([](auto& reg){ return reg.pixelRatio; });
-            queueResource(Resource::spriteImage(parser.spriteURL, pixelRatio));
-            queueResource(Resource::spriteJSON(parser.spriteURL, pixelRatio));
+            // Always request 1x and @2x sprite images for portability.
+            queueResource(Resource::spriteImage(parser.spriteURL, 1));
+            queueResource(Resource::spriteImage(parser.spriteURL, 2));
+            queueResource(Resource::spriteJSON(parser.spriteURL, 1));
+            queueResource(Resource::spriteJSON(parser.spriteURL, 2));
         }
 
         continueDownload();

test/storage/offline_download.test.cpp

@@ -214,7 +214,8 @@ TEST(OfflineDownload, Activate) {
     };
 
     test.fileSource.spriteImageResponse = [&] (const Resource& resource) {
-        EXPECT_EQ("http://127.0.0.1:3000/sprite.png", resource.url);
+        EXPECT_TRUE(resource.url == "http://127.0.0.1:3000/sprite.png" ||
+                    resource.url == "http://127.0.0.1:3000/sprite@2x.png");
         return test.response("sprite.png");
     };
 
@@ -224,7 +225,8 @@ TEST(OfflineDownload, Activate) {
     };
 
     test.fileSource.spriteJSONResponse = [&] (const Resource& resource) {
-        EXPECT_EQ("http://127.0.0.1:3000/sprite.json", resource.url);
+        EXPECT_TRUE(resource.url == "http://127.0.0.1:3000/sprite.json" ||
+                    resource.url == "http://127.0.0.1:3000/sprite@2x.json");
         return test.response("sprite.json");
     };
 
@@ -251,7 +253,7 @@ TEST(OfflineDownload, Activate) {
 
     observer->statusChangedFn = [&] (OfflineRegionStatus status) {
         if (status.complete()) {
-            EXPECT_EQ(262u, status.completedResourceCount); // 256 glyphs, 1 tile, 1 style, source, image, sprite image, and sprite json
+            EXPECT_EQ(264u, status.completedResourceCount); // 256 glyphs, 2 sprite images, 2 sprite jsons, 1 tile, 1 style, source, image
             EXPECT_EQ(test.size, status.completedResourceSize);
 
             download.setState(OfflineRegionDownloadState::Inactive);
@@ -334,7 +336,7 @@ TEST(OfflineDownload, GetStatusStyleComplete) {
     EXPECT_EQ(OfflineRegionDownloadState::Inactive, status.downloadState);
     EXPECT_EQ(1u, status.completedResourceCount);
     EXPECT_EQ(test.size, status.completedResourceSize);
-    EXPECT_EQ(261u, status.requiredResourceCount);
+    EXPECT_EQ(263u, status.requiredResourceCount);
     EXPECT_FALSE(status.requiredResourceCountIsPrecise);
     EXPECT_FALSE(status.complete());
 }
@@ -361,7 +363,7 @@ TEST(OfflineDownload, GetStatusStyleAndSourceComplete) {
     EXPECT_EQ(OfflineRegionDownloadState::Inactive, status.downloadState);
     EXPECT_EQ(2u, status.completedResourceCount);
     EXPECT_EQ(test.size, status.completedResourceSize);
-    EXPECT_EQ(262u, status.requiredResourceCount);
+    EXPECT_EQ(264u, status.requiredResourceCount);
     EXPECT_TRUE(status.requiredResourceCountIsPrecise);
     EXPECT_FALSE(status.complete());
 }