[google_maps_flutter] Fix ios tile overlay not loading when dealing with wide gamut images (#6377)

Fixes flutter/flutter#135252
Google maps does not currently support the use of wide gamut images.
Since engine uses 16 bit floats when dealing with wide gamut images
([here](https://github.com/flutter/engine/blob/8a51e124fbf168295a1b05f8d66459bfb29ae8a9/shell/platform/darwin/ios/framework/Source/FlutterView.mm#L125)),
when we detect that an image is using that format, we downsample it.



https://github.com/flutter/packages/assets/36148254/2d67418d-53a9-472b-b03e-86fb24f9610c


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- [x] I updated `CHANGELOG.md` to add a description of the change,
[following repository CHANGELOG style].
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
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- [x] All existing and new tests are passing.

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Author: LouiseHsu

packages/google_maps_flutter/google_maps_flutter_ios/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 2.5.2
+
+* Fixes the tile overlay not correctly displaying on physical ios devices.
+
 ## 2.5.1
 
 * Makes the tile overlay callback invoke the platform channel on the platform thread.

packages/google_maps_flutter/google_maps_flutter_ios/example/ios12/ios/Runner.xcodeproj/xcshareddata/xcschemes/Runner.xcscheme

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "1430"
+   LastUpgradeVersion = "1510"
    version = "1.3">
    <BuildAction
       parallelizeBuildables = "YES"

packages/google_maps_flutter/google_maps_flutter_ios/example/ios14/ios/Runner.xcodeproj/project.pbxproj

@@ -17,6 +17,7 @@
 		97C146FE1CF9000F007C117D /* Assets.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = 97C146FD1CF9000F007C117D /* Assets.xcassets */; };
 		97C147011CF9000F007C117D /* LaunchScreen.storyboard in Resources */ = {isa = PBXBuildFile; fileRef = 97C146FF1CF9000F007C117D /* LaunchScreen.storyboard */; };
 		982F2A6C27BADE17003C81F4 /* PartiallyMockedMapView.m in Sources */ = {isa = PBXBuildFile; fileRef = 982F2A6B27BADE17003C81F4 /* PartiallyMockedMapView.m */; };
+		F269303B2BB389BF00BF17C4 /* assets in Resources */ = {isa = PBXBuildFile; fileRef = F269303A2BB389BF00BF17C4 /* assets */; };
 		F7151F13265D7ED70028CB91 /* GoogleMapsTests.m in Sources */ = {isa = PBXBuildFile; fileRef = F7151F12265D7ED70028CB91 /* GoogleMapsTests.m */; };
 		FC8F35FC8CD533B128950487 /* libPods-RunnerTests.a in Frameworks */ = {isa = PBXBuildFile; fileRef = F267F68029D1A4E2E4C572A7 /* libPods-RunnerTests.a */; };
 /* End PBXBuildFile section */
@@ -68,6 +69,7 @@
 		E52C6A6210A56F027C582EF9 /* Pods-RunnerTests.debug.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-RunnerTests.debug.xcconfig"; path = "Pods/Target Support Files/Pods-RunnerTests/Pods-RunnerTests.debug.xcconfig"; sourceTree = "<group>"; };
 		EA0E91726245EDC22B97E8B9 /* Pods-Runner.release.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-Runner.release.xcconfig"; path = "Pods/Target Support Files/Pods-Runner/Pods-Runner.release.xcconfig"; sourceTree = "<group>"; };
 		F267F68029D1A4E2E4C572A7 /* libPods-RunnerTests.a */ = {isa = PBXFileReference; explicitFileType = archive.ar; includeInIndex = 0; path = "libPods-RunnerTests.a"; sourceTree = BUILT_PRODUCTS_DIR; };
+		F269303A2BB389BF00BF17C4 /* assets */ = {isa = PBXFileReference; lastKnownFileType = folder; path = assets; sourceTree = "<group>"; };
 		F7151F10265D7ED70028CB91 /* RunnerTests.xctest */ = {isa = PBXFileReference; explicitFileType = wrapper.cfbundle; includeInIndex = 0; path = RunnerTests.xctest; sourceTree = BUILT_PRODUCTS_DIR; };
 		F7151F12265D7ED70028CB91 /* GoogleMapsTests.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = GoogleMapsTests.m; sourceTree = "<group>"; };
 		F7151F14265D7ED70028CB91 /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
@@ -174,6 +176,7 @@
 		F7151F11265D7ED70028CB91 /* RunnerTests */ = {
 			isa = PBXGroup;
 			children = (
+				F269303A2BB389BF00BF17C4 /* assets */,
 				F7151F12265D7ED70028CB91 /* GoogleMapsTests.m */,
 				982F2A6A27BADE17003C81F4 /* PartiallyMockedMapView.h */,
 				982F2A6B27BADE17003C81F4 /* PartiallyMockedMapView.m */,
@@ -232,6 +235,7 @@
 		97C146E61CF9000F007C117D /* Project object */ = {
 			isa = PBXProject;
 			attributes = {
+				LastSwiftUpdateCheck = 1530;
 				LastUpgradeCheck = 1510;
 				ORGANIZATIONNAME = "The Flutter Authors";
 				TargetAttributes = {
@@ -280,6 +284,7 @@
 			isa = PBXResourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				F269303B2BB389BF00BF17C4 /* assets in Resources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -596,6 +601,7 @@
 				BUNDLE_LOADER = "$(TEST_HOST)";
 				CLANG_ENABLE_MODULES = YES;
 				CODE_SIGN_STYLE = Automatic;
+				DEVELOPMENT_TEAM = "";
 				"EXCLUDED_ARCHS[sdk=iphonesimulator*]" = "i386 arm64";
 				INFOPLIST_FILE = RunnerTests/Info.plist;
 				LD_RUNPATH_SEARCH_PATHS = (

packages/google_maps_flutter/google_maps_flutter_ios/example/ios14/ios/RunnerTests/GoogleMapsTests.m

@@ -17,6 +17,10 @@ @interface FLTGoogleMapFactory (Test)
 @interface GoogleMapsTests : XCTestCase
 @end
 
+@interface FLTTileProviderController (Testing)
+- (UIImage *)handleResultTile:(nullable UIImage *)tileImage;
+@end
+
 @implementation GoogleMapsTests
 
 - (void)testPlugin {
@@ -62,4 +66,23 @@ - (void)testMapsServiceSync {
   XCTAssertEqual(factory1.sharedMapServices, factory2.sharedMapServices);
 }
 
+- (void)testHandleResultTileDownsamplesWideGamutImages {
+  FLTTileProviderController *controller = [[FLTTileProviderController alloc] init];
+
+  NSString *imagePath = [[NSBundle bundleForClass:[self class]] pathForResource:@"widegamut"
+                                                                         ofType:@"png"
+                                                                    inDirectory:@"assets"];
+  UIImage *wideGamutImage = [UIImage imageWithContentsOfFile:imagePath];
+
+  XCTAssertNotNil(wideGamutImage, @"The image should be loaded.");
+
+  UIImage *downsampledImage = [controller handleResultTile:wideGamutImage];
+
+  CGImageRef imageRef = downsampledImage.CGImage;
+  size_t bitsPerComponent = CGImageGetBitsPerComponent(imageRef);
+
+  // non wide gamut images use 8 bit format
+  XCTAssert(bitsPerComponent == 8);
+}
+
 @end

packages/google_maps_flutter/google_maps_flutter_ios/example/ios14/ios/RunnerTests/assets/widegamut.png

@@ -118,6 +118,29 @@ - (instancetype)init:(FlutterMethodChannel *)methodChannel
 
 #pragma mark - GMSTileLayer method
 
+- (UIImage *)handleResultTile:(nullable UIImage *)tile {
+  CGImageRef imageRef = tile.CGImage;
+  CGBitmapInfo bitmapInfo = CGImageGetBitmapInfo(imageRef);
+  BOOL isFloat = bitmapInfo && kCGBitmapFloatComponents;
+  size_t bitsPerComponent = CGImageGetBitsPerComponent(imageRef);
+
+  // Engine use f16 pixel format for wide gamut images
+  // If it is wide gamut, we want to downsample it
+  if (isFloat & (bitsPerComponent == 16)) {
+    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
+    CGContextRef context = CGBitmapContextCreate(nil, tile.size.width, tile.size.height, 8, 0,
+                                                 colorSpace, kCGImageAlphaPremultipliedLast);
+    CGContextDrawImage(context, CGRectMake(0, 0, tile.size.width, tile.size.height), tile.CGImage);
+    CGImageRef image = CGBitmapContextCreateImage(context);
+    tile = [UIImage imageWithCGImage:image];
+
+    CGImageRelease(image);
+    CGContextRelease(context);
+    CGColorSpaceRelease(colorSpace);
+  }
+  return tile;
+}
+
 - (void)requestTileForX:(NSUInteger)x
                       y:(NSUInteger)y
                    zoom:(NSUInteger)zoom
@@ -137,7 +160,7 @@ - (void)requestTileForX:(NSUInteger)x
             if (typedData == nil) {
               tileImage = kGMSTileLayerNoTile;
             } else {
-              tileImage = [UIImage imageWithData:typedData.data];
+              tileImage = [self handleResultTile:[UIImage imageWithData:typedData.data]];
             }
           } else {
             if ([result isKindOfClass:[FlutterError class]]) {
@@ -150,7 +173,6 @@ - (void)requestTileForX:(NSUInteger)x
             }
             tileImage = kGMSTileLayerNoTile;
           }
-
           [receiver receiveTileWithX:x y:y zoom:zoom image:tileImage];
         }];
   });

packages/google_maps_flutter/google_maps_flutter_ios/ios/Classes/FLTGoogleMapTileOverlayController.m

@@ -2,7 +2,7 @@ name: google_maps_flutter_ios
 description: iOS implementation of the google_maps_flutter plugin.
 repository: https://github.com/flutter/packages/tree/main/packages/google_maps_flutter/google_maps_flutter_ios
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+maps%22
-version: 2.5.1
+version: 2.5.2
 
 environment:
   sdk: ^3.2.3