Feature/ios performances

.gitignore

@@ -15,7 +15,10 @@
 /cmake-build-debug
 /platform/android/build
 /platform/android/MapboxGLAndroidSDK/src/main/assets/sdk_versions/com.mapbox.mapboxsdk
+/platform/ios/platform/ios/Mapbox.playground/build/
 *.code-workspace
+
+.DS_Store
 /build
 **/.idea
 /platform/android/MapboxGLAndroidSDKTestApp/local.properties

platform/ios/platform/ios/ios.xcodeproj/project.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>IDEDidComputeMac32BitWarning</key>
+	<true/>
+</dict>
+</plist>

platform/ios/platform/ios/ios.xcodeproj/xcshareddata/xcschemes/iosapp.xcscheme

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "1120"
+   LastUpgradeVersion = "1240"
    version = "1.3">
    <BuildAction
       parallelizeBuildables = "YES"
@@ -15,7 +15,7 @@
             <BuildableReference
                BuildableIdentifier = "primary"
                BlueprintIdentifier = "DA1DC9491CB6C1C2006E619F"
-               BuildableName = "Mapbox GL.app"
+               BuildableName = "MapLibre GL.app"
                BlueprintName = "iosapp"
                ReferencedContainer = "container:ios.xcodeproj">
             </BuildableReference>
@@ -31,7 +31,7 @@
          <BuildableReference
             BuildableIdentifier = "primary"
             BlueprintIdentifier = "DA1DC9491CB6C1C2006E619F"
-            BuildableName = "Mapbox GL.app"
+            BuildableName = "MapLibre GL.app"
             BlueprintName = "iosapp"
             ReferencedContainer = "container:ios.xcodeproj">
          </BuildableReference>
@@ -54,7 +54,7 @@
          <BuildableReference
             BuildableIdentifier = "primary"
             BlueprintIdentifier = "DA1DC9491CB6C1C2006E619F"
-            BuildableName = "Mapbox GL.app"
+            BuildableName = "MapLibre GL.app"
             BlueprintName = "iosapp"
             ReferencedContainer = "container:ios.xcodeproj">
          </BuildableReference>
@@ -78,7 +78,7 @@
          <BuildableReference
             BuildableIdentifier = "primary"
             BlueprintIdentifier = "DA1DC9491CB6C1C2006E619F"
-            BuildableName = "Mapbox GL.app"
+            BuildableName = "MapLibre GL.app"
             BlueprintName = "iosapp"
             ReferencedContainer = "container:ios.xcodeproj">
          </BuildableReference>

platform/ios/platform/ios/src/MGLMapView.mm

@@ -158,6 +158,12 @@ typedef NS_ENUM(NSUInteger, MGLUserTrackingState) {
 /// The threshold used to consider when a tilt gesture should start.
 const CLLocationDegrees MGLHorizontalTiltToleranceDegrees = 45.0;
 
+/// The time between background snapshot attempts.
+const NSTimeInterval MGLBackgroundSnapshotImageInterval = 60.0;
+
+/// The delay after the map has idled before a background snapshot is attempted.
+const NSTimeInterval MGLBackgroundSnapshotImageIdleDelay = 3.0;
+
 /// Mapping from an annotation tag to metadata about that annotation, including
 /// the annotation itself.
 typedef std::unordered_map<MGLAnnotationTag, MGLAnnotationContext> MGLAnnotationTagContextMap;
@@ -1552,23 +1558,27 @@ - (void)pauseRendering:(__unused NSNotification *)notification
         _displayLink.paused = YES;
         [self processPendingBlocks];
 
-        if ( ! self.glSnapshotView)
+        if (self.lastSnapshotImage)
         {
-            self.glSnapshotView = [[UIImageView alloc] initWithFrame: _mbglView->getView().frame];
-            self.glSnapshotView.autoresizingMask = _mbglView->getView().autoresizingMask;
-            self.glSnapshotView.contentMode = UIViewContentModeCenter;
-            [self insertSubview:self.glSnapshotView aboveSubview:_mbglView->getView()];
-        }
-
-        self.glSnapshotView.image = self.lastSnapshotImage;
-        self.glSnapshotView.hidden = NO;
+            if ( ! self.glSnapshotView)
+            {
+               self.glSnapshotView = [[UIImageView alloc] initWithFrame: _mbglView->getView().frame];
+               self.glSnapshotView.autoresizingMask = _mbglView->getView().autoresizingMask;
+               self.glSnapshotView.contentMode = UIViewContentModeCenter;
+               [self insertSubview:self.glSnapshotView aboveSubview:_mbglView->getView()];
+           }
+
+            self.glSnapshotView.image = self.lastSnapshotImage;
+            self.glSnapshotView.hidden = NO;
+            self.glSnapshotView.alpha = 1;
 
-        if (self.debugMask && [self.glSnapshotView.subviews count] == 0)
-        {
-            UIView *snapshotTint = [[UIView alloc] initWithFrame:self.glSnapshotView.bounds];
-            snapshotTint.autoresizingMask = self.glSnapshotView.autoresizingMask;
-            snapshotTint.backgroundColor = [[UIColor redColor] colorWithAlphaComponent:0.25];
-            [self.glSnapshotView addSubview:snapshotTint];
+            if (self.debugMask && [self.glSnapshotView.subviews count] == 0)
+            {
+                UIView *snapshotTint = [[UIView alloc] initWithFrame:self.glSnapshotView.bounds];
+                snapshotTint.autoresizingMask = self.glSnapshotView.autoresizingMask;
+                snapshotTint.backgroundColor = [[UIColor redColor] colorWithAlphaComponent:0.25];
+                [self.glSnapshotView addSubview:snapshotTint];
+            }
         }
 
         _mbglView->deleteView();
@@ -1586,9 +1596,15 @@ - (void)resumeRendering:(__unused NSNotification *)notification
 
         _mbglView->createView();
 
-        self.glSnapshotView.hidden = YES;
-
-        [self.glSnapshotView.subviews makeObjectsPerformSelector:@selector(removeFromSuperview)];
+        [UIView transitionWithView:self
+                                 duration:0.25
+                                  options:UIViewAnimationOptionTransitionCrossDissolve
+                               animations:^{
+                   self.glSnapshotView.hidden = YES;
+               }
+                               completion:^(BOOL finished) {
+                   [self.glSnapshotView.subviews makeObjectsPerformSelector:@selector(removeFromSuperview)];
+        }];
 
         _displayLink.paused = NO;
 
@@ -5946,29 +5962,32 @@ - (void)dismissHeadingCalibrationDisplay:(id<MGLLocationManager>)manager
 
 - (void)locationManager:(__unused id<MGLLocationManager>)manager didUpdateHeading:(CLHeading *)newHeading
 {
-    if ( ! _showsUserLocation || self.pan.state == UIGestureRecognizerStateBegan || newHeading.headingAccuracy < 0) return;
+    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^(void) {
+        if ( ! self->_showsUserLocation || self.pan.state == UIGestureRecognizerStateBegan || newHeading.headingAccuracy < 0) return;
 
-    self.userLocation.heading = newHeading;
+        self.userLocation.heading = newHeading;
 
-    if (self.showsUserHeadingIndicator || self.userTrackingMode == MGLUserTrackingModeFollowWithHeading)
-    {
-        [self updateUserLocationAnnotationView];
-    }
+        if (self.showsUserHeadingIndicator || self.userTrackingMode == MGLUserTrackingModeFollowWithHeading)
+        {
+            [self updateUserLocationAnnotationView];
+        }
 
-    if ([self.delegate respondsToSelector:@selector(mapView:didUpdateUserLocation:)])
-    {
-        [self.delegate mapView:self didUpdateUserLocation:self.userLocation];
+        if ([self.delegate respondsToSelector:@selector(mapView:didUpdateUserLocation:)])
+        {
+            [self.delegate mapView:self didUpdateUserLocation:self.userLocation];
 
-        if ( ! _showsUserLocation) return;
-    }
+            if (!self->_showsUserLocation) return;
+        }
 
-    CLLocationDirection headingDirection = (newHeading.trueHeading >= 0 ? newHeading.trueHeading : newHeading.magneticHeading);
+        CLLocationDirection headingDirection = (newHeading.trueHeading >= 0 ? newHeading.trueHeading : newHeading.magneticHeading);
 
-    if (headingDirection >= 0 && self.userTrackingMode == MGLUserTrackingModeFollowWithHeading
-        && self.userTrackingState != MGLUserTrackingStateBegan)
-    {
-        [self _setDirection:headingDirection animated:YES];
-    }
+        if (headingDirection >= 0 && self.userTrackingMode == MGLUserTrackingModeFollowWithHeading
+            && self.userTrackingState != MGLUserTrackingStateBegan)
+        {
+            [self _setDirection:headingDirection animated:YES];
+            [self updateUserLocationAnnotationView];
+        }
+    });
 }
 
 - (void)locationManager:(__unused id<MGLLocationManager>)manager didFailWithError:(NSError *)error
@@ -6353,6 +6372,8 @@ - (void)mapViewDidFailLoadingMapWithError:(NSError *)error {
 }
 
 - (void)mapViewWillStartRenderingFrame {
+    [self cancelBackgroundSnapshot];
+
     if (!_mbglMap)
     {
         return;
@@ -6412,7 +6433,9 @@ - (void)mapViewDidBecomeIdle {
     if (!_mbglMap) {
         return;
     }
-
+
+    [self queueBackgroundSnapshot];
+
     if ([self.delegate respondsToSelector:@selector(mapViewDidBecomeIdle:)]) {
         [self.delegate mapViewDidBecomeIdle:self];
     }
@@ -6891,6 +6914,39 @@ - (void)prepareForInterfaceBuilder
     return _annotationViewReuseQueueByIdentifier[identifier];
 }
 
+#pragma mark - Snapshot image -
+
+- (void)attemptBackgroundSnapshot {
+    static NSTimeInterval lastSnapshotTime = 0.0;
+
+    if ([UIApplication sharedApplication].applicationState != UIApplicationStateActive) {
+        return;
+    }
+
+    NSTimeInterval now = CACurrentMediaTime();
+
+    if (lastSnapshotTime == 0.0 || (now - lastSnapshotTime > MGLBackgroundSnapshotImageInterval)) {
+        self.lastSnapshotImage = _mbglView->snapshot();
+        lastSnapshotTime = now;
+    }
+}
+
+- (void)cancelBackgroundSnapshot
+{
+    [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(attemptBackgroundSnapshot) object:nil];
+}
+
+- (void)queueBackgroundSnapshot {
+    if ([UIApplication sharedApplication].applicationState != UIApplicationStateActive) {
+        return;
+    }
+
+    [self cancelBackgroundSnapshot];
+    [self performSelector:@selector(attemptBackgroundSnapshot)
+               withObject:nil
+               afterDelay:MGLBackgroundSnapshotImageIdleDelay];
+}
+
 @end
 
 #pragma mark - IBAdditions methods