feat: add STEP-093 iPad validation menu

platform/ios/app/MBXViewController.mm

@@ -59,6 +59,19 @@ static const MLNCoordinateBounds colorado = {
 static NSString *const MBXViewControllerAnnotationViewReuseIdentifer =
     @"MBXViewControllerAnnotationViewReuseIdentifer";
 
+static NSString *const MBXStep093SourceBottom = @"step093-bottom-source";
+static NSString *const MBXStep093SourceTopSemi = @"step093-top-semi-source";
+static NSString *const MBXStep093SourceTopOpaque = @"step093-top-opaque-source";
+static NSString *const MBXStep093SourceTopLine = @"step093-top-line-source";
+static NSString *const MBXStep093SourceCross = @"step093-cross-source";
+static NSString *const MBXStep093LayerBottom = @"step093-bottom-fill";
+static NSString *const MBXStep093LayerTopSemi = @"step093-top-semi";
+static NSString *const MBXStep093LayerTopOpaque = @"step093-top-opaque";
+static NSString *const MBXStep093LayerTopLine = @"step093-top-line";
+static NSString *const MBXStep093LayerCross = @"step093-cross-layer";
+static NSString *const MBXStep093WeatherLayer = @"particle-qbin-v4-smoke-weather";
+static NSString *const MBXStep093ParticleLayer = @"particle-qbin-v4-smoke-particles";
+
 typedef NS_ENUM(NSInteger, MBXSettingsSections) {
   MBXSettingsDebugTools = 0,
   MBXSettingsAnnotations,
@@ -129,7 +142,22 @@ typedef NS_ENUM(NSInteger, MBXSettingsRuntimeStylingRows) {
   MBXSettingsRuntimeStylingAddFoursquarePOIsPMTiles,
   MBXSettingsRuntimeStylingHeatmapLayer,
   MBXSettingsRuntimeStylingParticleCoreValidation,
-  MBXSettingsRuntimeStylingParticleQbinV4Smoke
+  MBXSettingsRuntimeStylingParticleQbinV4Smoke,
+  MBXSettingsRuntimeStylingStep093
+};
+
+typedef NS_ENUM(NSInteger, MBXStep093Scenario) {
+  MBXStep093ScenarioBottomContinuousTop = 0,
+  MBXStep093ScenarioBottomContinuous,
+  MBXStep093ScenarioContinuousTop,
+  MBXStep093ScenarioContinuousOnly,
+  MBXStep093ScenarioSingleLayer
+};
+
+typedef NS_ENUM(NSInteger, MBXStep093CrossPosition) {
+  MBXStep093CrossPositionBottom = 0,
+  MBXStep093CrossPositionContinuous,
+  MBXStep093CrossPositionTop
 };
 
 typedef NS_ENUM(NSInteger, MBXSettingsMiscellaneousRows) {
@@ -262,6 +290,27 @@ CLLocationCoordinate2D randomWorldCoordinate(void) {
 - (void)showParticleQbinV4SmokeMenu;
 - (void)installParticleQbinV4SmokeAtTime:(uint64_t)requestedTime label:(NSString *)label;
 - (void)clearParticleQbinV4Smoke;
+- (void)showStep093Menu;
+- (void)showStep093InvalidRangeMenu;
+- (void)showStep093EndpointMenu;
+- (void)showStep093MutationMenu;
+- (void)installStep093Scenario:(MBXStep093Scenario)scenario;
+- (void)installStep093OrdinarySources;
+- (void)removeStep093BaseStyleLayers;
+- (void)clearStep093OrdinaryLayers;
+- (void)setStep093RangeStart:(NSString *)start end:(NSString *)end label:(NSString *)label;
+- (void)deleteStep093Endpoint:(NSString *)identifier;
+- (void)toggleStep093EndpointVisibility:(NSString *)identifier;
+- (void)moveStep093CrossLayer:(MBXStep093CrossPosition)position;
+- (void)showStep093Diagnostics;
+- (MLNFillStyleLayer *)step093FillLayer:(NSString *)identifier
+                                 source:(NSString *)sourceIdentifier
+                                  color:(UIColor *)color
+                                opacity:(CGFloat)opacity;
+- (MLNLineStyleLayer *)step093LineLayer:(NSString *)identifier
+                                 source:(NSString *)sourceIdentifier
+                                  color:(UIColor *)color
+                                  width:(CGFloat)width;
 @end
 
 @interface MLNMapView (MBXViewController)
@@ -523,7 +572,8 @@ CLLocationCoordinate2D randomWorldCoordinate(void) {
         @"Add FourSquare POIs PMTiles Layer",
         @"Add Earthquake Heatmap",
         @"Particle Core Validation (Fixtures)",
-        @"Particle / QBIN V4 Smoke (T0)"
+        @"Particle / QBIN V4 Smoke (T0)",
+        @"STEP-093 Continuous Range"
       ]];
       break;
     case MBXSettingsMiscellaneous:
@@ -763,6 +813,9 @@ CLLocationCoordinate2D randomWorldCoordinate(void) {
         case MBXSettingsRuntimeStylingParticleQbinV4Smoke:
           [self showParticleQbinV4SmokeMenu];
           break;
+        case MBXSettingsRuntimeStylingStep093:
+          [self showStep093Menu];
+          break;
         default:
           NSAssert(NO, @"All runtime styling setting rows should be implemented");
           break;
@@ -1391,6 +1444,7 @@ CLLocationCoordinate2D randomWorldCoordinate(void) {
 }
 
 - (void)clearParticleQbinV4Smoke {
+  [self clearStep093OrdinaryLayers];
   auto& style = [self.mapView mbglMap].getStyle();
   if (style.getLayer("particle-qbin-v4-smoke-particles")) style.removeLayer("particle-qbin-v4-smoke-particles");
   if (style.getLayer("particle-qbin-v4-smoke-weather")) style.removeLayer("particle-qbin-v4-smoke-weather");
@@ -1399,6 +1453,452 @@ CLLocationCoordinate2D randomWorldCoordinate(void) {
   NSLog(@"ParticleQbinV4Smoke: event=CLEAR_RELEASED");
 }
 
+// MARK: - STEP-093 Continuous Range runtime validation (test app only)
+
+- (void)showStep093Menu {
+  UIAlertController *menu =
+      [UIAlertController alertControllerWithTitle:@"STEP-093 Continuous Range"
+                                          message:@"Style order remains the only Z-order. Select a topology, then use the submenus to mutate it and refresh diagnostics."
+                                   preferredStyle:UIAlertControllerStyleAlert];
+  __weak MBXViewController *weakSelf = self;
+  void (^scenario)(NSString *, MBXStep093Scenario) = ^(NSString *title,
+                                                        MBXStep093Scenario value) {
+    [menu addAction:[UIAlertAction actionWithTitle:title
+                                             style:UIAlertActionStyleDefault
+                                           handler:^(__unused UIAlertAction *action) {
+                                             [weakSelf installStep093Scenario:value];
+                                           }]];
+  };
+  scenario(@"A Bottom + Continuous + Top", MBXStep093ScenarioBottomContinuousTop);
+  scenario(@"B Bottom + Continuous", MBXStep093ScenarioBottomContinuous);
+  scenario(@"C Continuous + Top", MBXStep093ScenarioContinuousTop);
+  scenario(@"D Continuous-only", MBXStep093ScenarioContinuousOnly);
+  scenario(@"E Single-layer Continuous", MBXStep093ScenarioSingleLayer);
+  [menu addAction:[UIAlertAction actionWithTitle:@"Invalid / Missing / Reversed"
+                                           style:UIAlertActionStyleDefault
+                                         handler:^(__unused UIAlertAction *action) {
+                                           [weakSelf showStep093InvalidRangeMenu];
+                                         }]];
+  [menu addAction:[UIAlertAction actionWithTitle:@"Endpoint / Visibility"
+                                           style:UIAlertActionStyleDefault
+                                         handler:^(__unused UIAlertAction *action) {
+                                           [weakSelf showStep093EndpointMenu];
+                                         }]];
+  [menu addAction:[UIAlertAction actionWithTitle:@"Mutation / Cross-boundary"
+                                           style:UIAlertActionStyleDefault
+                                         handler:^(__unused UIAlertAction *action) {
+                                           [weakSelf showStep093MutationMenu];
+                                         }]];
+  [menu addAction:[UIAlertAction actionWithTitle:@"Diagnostics / Refresh"
+                                           style:UIAlertActionStyleDefault
+                                         handler:^(__unused UIAlertAction *action) {
+                                           [weakSelf showStep093Diagnostics];
+                                         }]];
+  [menu addAction:[UIAlertAction actionWithTitle:@"Restore Default A"
+                                           style:UIAlertActionStyleDefault
+                                         handler:^(__unused UIAlertAction *action) {
+                                           [weakSelf installStep093Scenario:
+                                                         MBXStep093ScenarioBottomContinuousTop];
+                                         }]];
+  [menu addAction:[UIAlertAction actionWithTitle:@"Cancel"
+                                           style:UIAlertActionStyleCancel
+                                         handler:nil]];
+  [self presentViewController:menu animated:YES completion:nil];
+}
+
+- (void)showStep093InvalidRangeMenu {
+  UIAlertController *menu =
+      [UIAlertController alertControllerWithTitle:@"STEP-093 Invalid Range"
+                                          message:@"Each action first restores default A when its endpoints are unavailable."
+                                   preferredStyle:UIAlertControllerStyleAlert];
+  __weak MBXViewController *weakSelf = self;
+  void (^ensureDefault)(void) = ^{
+    if (![weakSelf.mapView.style layerWithIdentifier:MBXStep093WeatherLayer] ||
+        ![weakSelf.mapView.style layerWithIdentifier:MBXStep093ParticleLayer]) {
+      [weakSelf installStep093Scenario:MBXStep093ScenarioBottomContinuousTop];
+    }
+  };
+  [menu addAction:[UIAlertAction actionWithTitle:@"Missing start"
+                                           style:UIAlertActionStyleDefault
+                                         handler:^(__unused UIAlertAction *action) {
+                                           ensureDefault();
+                                           [weakSelf setStep093RangeStart:@"step093-missing-start"
+                                                                     end:MBXStep093ParticleLayer
+                                                                   label:@"MISSING_START"];
+                                         }]];
+  [menu addAction:[UIAlertAction actionWithTitle:@"Missing end"
+                                           style:UIAlertActionStyleDefault
+                                         handler:^(__unused UIAlertAction *action) {
+                                           ensureDefault();
+                                           [weakSelf setStep093RangeStart:MBXStep093WeatherLayer
+                                                                     end:@"step093-missing-end"
+                                                                   label:@"MISSING_END"];
+                                         }]];
+  [menu addAction:[UIAlertAction actionWithTitle:@"Reversed endpoints"
+                                           style:UIAlertActionStyleDefault
+                                         handler:^(__unused UIAlertAction *action) {
+                                           ensureDefault();
+                                           [weakSelf setStep093RangeStart:MBXStep093ParticleLayer
+                                                                     end:MBXStep093WeatherLayer
+                                                                   label:@"REVERSED"];
+                                         }]];
+  [menu addAction:[UIAlertAction actionWithTitle:@"Empty start ID (API reject)"
+                                           style:UIAlertActionStyleDefault
+                                         handler:^(__unused UIAlertAction *action) {
+                                           ensureDefault();
+                                           [weakSelf setStep093RangeStart:@""
+                                                                     end:MBXStep093ParticleLayer
+                                                                   label:@"EMPTY_START"];
+                                         }]];
+  [menu addAction:[UIAlertAction actionWithTitle:@"Restore valid A"
+                                           style:UIAlertActionStyleDefault
+                                         handler:^(__unused UIAlertAction *action) {
+                                           [weakSelf installStep093Scenario:
+                                                         MBXStep093ScenarioBottomContinuousTop];
+                                         }]];
+  [menu addAction:[UIAlertAction actionWithTitle:@"Back"
+                                           style:UIAlertActionStyleCancel
+                                         handler:^(__unused UIAlertAction *action) {
+                                           [weakSelf showStep093Menu];
+                                         }]];
+  [self presentViewController:menu animated:YES completion:nil];
+}
+
+- (void)showStep093EndpointMenu {
+  UIAlertController *menu =
+      [UIAlertController alertControllerWithTitle:@"STEP-093 Endpoints"
+                                          message:@"Visibility changes content only; deletion must invalidate the configured endpoint. Restore rebuilds default A without replacing MLNMapView."
+                                   preferredStyle:UIAlertControllerStyleAlert];
+  __weak MBXViewController *weakSelf = self;
+  [menu addAction:[UIAlertAction actionWithTitle:@"Toggle start visibility"
+                                           style:UIAlertActionStyleDefault
+                                         handler:^(__unused UIAlertAction *action) {
+                                           [weakSelf toggleStep093EndpointVisibility:
+                                                         MBXStep093WeatherLayer];
+                                         }]];
+  [menu addAction:[UIAlertAction actionWithTitle:@"Toggle end visibility"
+                                           style:UIAlertActionStyleDefault
+                                         handler:^(__unused UIAlertAction *action) {
+                                           [weakSelf toggleStep093EndpointVisibility:
+                                                         MBXStep093ParticleLayer];
+                                         }]];
+  [menu addAction:[UIAlertAction actionWithTitle:@"Delete start endpoint"
+                                           style:UIAlertActionStyleDestructive
+                                         handler:^(__unused UIAlertAction *action) {
+                                           [weakSelf deleteStep093Endpoint:MBXStep093WeatherLayer];
+                                         }]];
+  [menu addAction:[UIAlertAction actionWithTitle:@"Restore start (default A)"
+                                           style:UIAlertActionStyleDefault
+                                         handler:^(__unused UIAlertAction *action) {
+                                           [weakSelf installStep093Scenario:
+                                                         MBXStep093ScenarioBottomContinuousTop];
+                                         }]];
+  [menu addAction:[UIAlertAction actionWithTitle:@"Delete end endpoint"
+                                           style:UIAlertActionStyleDestructive
+                                         handler:^(__unused UIAlertAction *action) {
+                                           [weakSelf deleteStep093Endpoint:MBXStep093ParticleLayer];
+                                         }]];
+  [menu addAction:[UIAlertAction actionWithTitle:@"Restore end (default A)"
+                                           style:UIAlertActionStyleDefault
+                                         handler:^(__unused UIAlertAction *action) {
+                                           [weakSelf installStep093Scenario:
+                                                         MBXStep093ScenarioBottomContinuousTop];
+                                         }]];
+  [menu addAction:[UIAlertAction actionWithTitle:@"Back"
+                                           style:UIAlertActionStyleCancel
+                                         handler:^(__unused UIAlertAction *action) {
+                                           [weakSelf showStep093Menu];
+                                         }]];
+  [self presentViewController:menu animated:YES completion:nil];
+}
+
+- (void)showStep093MutationMenu {
+  UIAlertController *menu =
+      [UIAlertController alertControllerWithTitle:@"STEP-093 Cross-boundary"
+                                          message:@"The same ordinary fill layer ID is removed and re-added at three Style-order positions."
+                                   preferredStyle:UIAlertControllerStyleAlert];
+  __weak MBXViewController *weakSelf = self;
+  void (^move)(NSString *, MBXStep093CrossPosition) = ^(NSString *title,
+                                                        MBXStep093CrossPosition position) {
+    [menu addAction:[UIAlertAction actionWithTitle:title
+                                             style:UIAlertActionStyleDefault
+                                           handler:^(__unused UIAlertAction *action) {
+                                             [weakSelf moveStep093CrossLayer:position];
+                                           }]];
+  };
+  move(@"Move cross layer → Bottom", MBXStep093CrossPositionBottom);
+  move(@"Move cross layer → Continuous", MBXStep093CrossPositionContinuous);
+  move(@"Move cross layer → Top", MBXStep093CrossPositionTop);
+  [menu addAction:[UIAlertAction actionWithTitle:@"Remove cross layer"
+                                           style:UIAlertActionStyleDestructive
+                                         handler:^(__unused UIAlertAction *action) {
+                                           [weakSelf removeLayer:MBXStep093LayerCross];
+                                           [weakSelf.mapView setNeedsRerender];
+                                           NSLog(@"STEP093_IOS event=MUTATION cross=REMOVED");
+                                         }]];
+  [menu addAction:[UIAlertAction actionWithTitle:@"Restore Default A"
+                                           style:UIAlertActionStyleDefault
+                                         handler:^(__unused UIAlertAction *action) {
+                                           [weakSelf installStep093Scenario:
+                                                         MBXStep093ScenarioBottomContinuousTop];
+                                         }]];
+  [menu addAction:[UIAlertAction actionWithTitle:@"Back"
+                                           style:UIAlertActionStyleCancel
+                                         handler:^(__unused UIAlertAction *action) {
+                                           [weakSelf showStep093Menu];
+                                         }]];
+  [self presentViewController:menu animated:YES completion:nil];
+}
+
+- (void)installStep093Scenario:(MBXStep093Scenario)scenario {
+  [self clearStep093OrdinaryLayers];
+  [self installParticleQbinV4SmokeAtTime:1789241400000ULL label:@"STEP093_MIDPOINT"];
+  if (![self.mapView.style layerWithIdentifier:MBXStep093WeatherLayer] ||
+      ![self.mapView.style layerWithIdentifier:MBXStep093ParticleLayer]) {
+    NSLog(@"STEP093_IOS event=SCENE_FAILED reason=QBIN_ENDPOINTS_UNAVAILABLE");
+    return;
+  }
+
+  [self removeStep093BaseStyleLayers];
+  [self installStep093OrdinarySources];
+  MLNStyle *style = self.mapView.style;
+  MLNStyleLayer *weather = [style layerWithIdentifier:MBXStep093WeatherLayer];
+  MLNStyleLayer *particle = [style layerWithIdentifier:MBXStep093ParticleLayer];
+  const BOOL hasBottom = scenario == MBXStep093ScenarioBottomContinuousTop ||
+                         scenario == MBXStep093ScenarioBottomContinuous ||
+                         scenario == MBXStep093ScenarioSingleLayer;
+  const BOOL hasTop = scenario == MBXStep093ScenarioBottomContinuousTop ||
+                      scenario == MBXStep093ScenarioContinuousTop ||
+                      scenario == MBXStep093ScenarioSingleLayer;
+
+  if (hasBottom) {
+    MLNFillStyleLayer *bottom =
+        [self step093FillLayer:MBXStep093LayerBottom
+                       source:MBXStep093SourceBottom
+                        color:[UIColor colorWithRed:0.05 green:0.48 blue:0.58 alpha:1.0]
+                      opacity:0.72];
+    [style insertLayer:bottom belowLayer:weather];
+  }
+  if (hasTop) {
+    [style addLayer:[self step093FillLayer:MBXStep093LayerTopSemi
+                                    source:MBXStep093SourceTopSemi
+                                     color:[UIColor colorWithRed:1.0 green:0.82 blue:0.27 alpha:1.0]
+                                   opacity:0.42]];
+    [style addLayer:[self step093FillLayer:MBXStep093LayerTopOpaque
+                                    source:MBXStep093SourceTopOpaque
+                                     color:[UIColor colorWithRed:0.94 green:0.20 blue:0.34 alpha:1.0]
+                                   opacity:1.0]];
+    [style addLayer:[self step093LineLayer:MBXStep093LayerTopLine
+                                    source:MBXStep093SourceTopLine
+                                     color:UIColor.whiteColor
+                                     width:6.0]];
+  }
+
+  NSString *start = MBXStep093WeatherLayer;
+  NSString *end = MBXStep093ParticleLayer;
+  if (scenario == MBXStep093ScenarioSingleLayer) {
+    start = MBXStep093ParticleLayer;
+    end = MBXStep093ParticleLayer;
+  }
+
+  self.mapView.retainedUnderlayEnabled = YES;
+  NSString *labels[] = {@"BOTTOM_CONTINUOUS_TOP", @"BOTTOM_CONTINUOUS",
+                        @"CONTINUOUS_TOP", @"CONTINUOUS_ONLY", @"SINGLE_LAYER"};
+  [self setStep093RangeStart:start end:end label:labels[scenario]];
+  [self.mapView setCenterCoordinate:CLLocationCoordinate2DMake(27.8882865, 135.0)
+                          zoomLevel:3.0
+                           animated:NO];
+  [self.mapView setNeedsRerender];
+}
+
+- (void)installStep093OrdinarySources {
+  MLNStyle *style = self.mapView.style;
+  MLNShapeSource *(^polygonSource)(NSString *, CLLocationCoordinate2D *, NSUInteger) =
+      ^MLNShapeSource *(NSString *identifier, CLLocationCoordinate2D *coordinates,
+                        NSUInteger count) {
+        MLNPolygon *polygon = [MLNPolygon polygonWithCoordinates:coordinates count:count];
+        return [[MLNShapeSource alloc] initWithIdentifier:identifier shape:polygon options:nil];
+      };
+
+  CLLocationCoordinate2D bottom[] = {{4.0, 114.0}, {4.0, 157.0}, {53.0, 157.0},
+                                     {53.0, 114.0}, {4.0, 114.0}};
+  CLLocationCoordinate2D semi[] = {{8.0, 136.0}, {8.0, 152.0}, {49.0, 152.0},
+                                   {49.0, 136.0}, {8.0, 136.0}};
+  CLLocationCoordinate2D opaque[] = {{18.0, 124.0}, {18.0, 136.0}, {42.0, 136.0},
+                                     {42.0, 124.0}, {18.0, 124.0}};
+  CLLocationCoordinate2D cross[] = {{14.0, 128.0}, {14.0, 145.0}, {37.0, 145.0},
+                                    {37.0, 128.0}, {14.0, 128.0}};
+  CLLocationCoordinate2D line[] = {{6.0, 116.0}, {50.0, 154.0}, {6.0, 154.0},
+                                   {50.0, 116.0}};
+  [style addSource:polygonSource(MBXStep093SourceBottom, bottom, 5)];
+  [style addSource:polygonSource(MBXStep093SourceTopSemi, semi, 5)];
+  [style addSource:polygonSource(MBXStep093SourceTopOpaque, opaque, 5)];
+  [style addSource:[[MLNShapeSource alloc]
+                       initWithIdentifier:MBXStep093SourceTopLine
+                                    shape:[MLNPolyline polylineWithCoordinates:line count:4]
+                                  options:nil]];
+  [style addSource:polygonSource(MBXStep093SourceCross, cross, 5)];
+}
+
+- (void)removeStep093BaseStyleLayers {
+  // The demo style normally contains many pre-existing layers. Remove them from this private
+  // validation scene so A/B/C/D describe the complete Style topology rather than only a suffix.
+  // The QBIN source and the two existing dynamic endpoints remain untouched.
+  for (MLNStyleLayer *layer in [self.mapView.style.layers copy]) {
+    if (![layer.identifier isEqualToString:MBXStep093WeatherLayer] &&
+        ![layer.identifier isEqualToString:MBXStep093ParticleLayer]) {
+      [self.mapView.style removeLayer:layer];
+    }
+  }
+}
+
+- (void)clearStep093OrdinaryLayers {
+  for (NSString *identifier in @[ MBXStep093LayerCross, MBXStep093LayerTopLine,
+                                  MBXStep093LayerTopOpaque, MBXStep093LayerTopSemi,
+                                  MBXStep093LayerBottom ]) {
+    [self removeLayer:identifier];
+  }
+  for (NSString *identifier in @[ MBXStep093SourceCross, MBXStep093SourceTopLine,
+                                  MBXStep093SourceTopOpaque, MBXStep093SourceTopSemi,
+                                  MBXStep093SourceBottom ]) {
+    [self removeSource:identifier];
+  }
+}
+
+- (void)setStep093RangeStart:(NSString *)start end:(NSString *)end label:(NSString *)label {
+  BOOL accepted = [self.mapView setContinuousLayerRangeFromLayerIdentifier:start
+                                                         toLayerIdentifier:end];
+  [self.mapView setNeedsRerender];
+  NSLog(@"STEP093_IOS event=RANGE label=%@ accepted=%d start=%@ end=%@", label, accepted,
+        start, end);
+}
+
+- (void)deleteStep093Endpoint:(NSString *)identifier {
+  if (![self.mapView.style layerWithIdentifier:MBXStep093WeatherLayer] ||
+      ![self.mapView.style layerWithIdentifier:MBXStep093ParticleLayer]) {
+    [self installStep093Scenario:MBXStep093ScenarioBottomContinuousTop];
+  }
+  [self removeLayer:identifier];
+  [self.mapView setNeedsRerender];
+  NSLog(@"STEP093_IOS event=ENDPOINT_DELETE id=%@", identifier);
+}
+
+- (void)toggleStep093EndpointVisibility:(NSString *)identifier {
+  MLNStyleLayer *layer = [self.mapView.style layerWithIdentifier:identifier];
+  if (!layer) {
+    [self installStep093Scenario:MBXStep093ScenarioBottomContinuousTop];
+    layer = [self.mapView.style layerWithIdentifier:identifier];
+  }
+  layer.visible = !layer.visible;
+  [self.mapView setNeedsRerender];
+  NSLog(@"STEP093_IOS event=ENDPOINT_VISIBILITY id=%@ visible=%d", identifier,
+        layer.visible);
+}
+
+- (void)moveStep093CrossLayer:(MBXStep093CrossPosition)position {
+  if (![self.mapView.style sourceWithIdentifier:MBXStep093SourceCross] ||
+      ![self.mapView.style layerWithIdentifier:MBXStep093WeatherLayer] ||
+      ![self.mapView.style layerWithIdentifier:MBXStep093ParticleLayer]) {
+    [self installStep093Scenario:MBXStep093ScenarioBottomContinuousTop];
+  }
+  [self removeLayer:MBXStep093LayerCross];
+  MLNFillStyleLayer *cross =
+      [self step093FillLayer:MBXStep093LayerCross
+                     source:MBXStep093SourceCross
+                      color:[UIColor colorWithRed:0.62 green:0.25 blue:0.78 alpha:1.0]
+                    opacity:0.28];
+  MLNStyle *style = self.mapView.style;
+  MLNStyleLayer *weather = [style layerWithIdentifier:MBXStep093WeatherLayer];
+  MLNStyleLayer *particle = [style layerWithIdentifier:MBXStep093ParticleLayer];
+  NSString *label = nil;
+  switch (position) {
+    case MBXStep093CrossPositionBottom:
+      [style insertLayer:cross belowLayer:weather];
+      label = @"BOTTOM";
+      break;
+    case MBXStep093CrossPositionContinuous:
+      [style insertLayer:cross belowLayer:particle];
+      label = @"CONTINUOUS";
+      break;
+    case MBXStep093CrossPositionTop:
+      [style insertLayer:cross aboveLayer:particle];
+      label = @"TOP";
+      break;
+  }
+  [self.mapView setNeedsRerender];
+  NSLog(@"STEP093_IOS event=MUTATION cross=%@", label);
+}
+
+- (void)showStep093Diagnostics {
+  MLNRetainedUnderlayDiagnostics *value = self.mapView.retainedUnderlayDiagnostics;
+  NSUInteger cacheCount = (value.bottomPresent ? 1 : 0) + (value.topPresent ? 1 : 0);
+  NSString *message = [NSString
+      stringWithFormat:
+          @"Range configured=%d valid=%d fallback=%d\n%@[%ld] … %@[%ld]\nContinuous=[%ld,%ld) caches=%lu\nreason=%@\n\nBottom present=%d state=%@\nb/r/i=%llu/%llu/%llu\ntex/comp/release=%llu/%llu/%llu\nlast=%@\n\nTop present=%d state=%@\nb/r/i=%llu/%llu/%llu\ntex/comp/release=%llu/%llu/%llu\nlast=%@\n\nFast eligible=%d active=%d\nhit/miss/full=%llu/%llu/%llu\nreason=%@",
+          value.rangeConfigured, value.rangeValid, value.rangeFallback, value.startLayerId,
+          (long)value.startIndex, value.endLayerId, (long)value.endIndex,
+          (long)value.continuousBegin, (long)value.continuousEndExclusive,
+          (unsigned long)cacheCount, value.lastReason, value.bottomPresent,
+          value.bottomCacheState, (unsigned long long)value.bottomBuild,
+          (unsigned long long)value.bottomReuse, (unsigned long long)value.bottomInvalidation,
+          (unsigned long long)value.bottomTextureCreate,
+          (unsigned long long)value.bottomCompositeCreate,
+          (unsigned long long)value.bottomResourceRelease, value.bottomLastInvalidationReason,
+          value.topPresent, value.topCacheState, (unsigned long long)value.topBuild,
+          (unsigned long long)value.topReuse, (unsigned long long)value.topInvalidation,
+          (unsigned long long)value.topTextureCreate,
+          (unsigned long long)value.topCompositeCreate,
+          (unsigned long long)value.topResourceRelease, value.topLastInvalidationReason,
+          value.fastPathEligible, value.fastPathActive, (unsigned long long)value.fastPathHit,
+          (unsigned long long)value.fastPathMiss, (unsigned long long)value.fullCpuFrame,
+          value.fastPathFallbackReason];
+  NSLog(@"STEP093_IOS_DIAGNOSTICS %@", [message stringByReplacingOccurrencesOfString:@"\n"
+                                                                                  withString:@" "]);
+  UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"STEP-093 Diagnostics"
+                                                                  message:message
+                                                           preferredStyle:UIAlertControllerStyleAlert];
+  __weak MBXViewController *weakSelf = self;
+  [alert addAction:[UIAlertAction actionWithTitle:@"Refresh"
+                                            style:UIAlertActionStyleDefault
+                                          handler:^(__unused UIAlertAction *action) {
+                                            [weakSelf showStep093Diagnostics];
+                                          }]];
+  [alert addAction:[UIAlertAction actionWithTitle:@"Back to STEP-093"
+                                            style:UIAlertActionStyleDefault
+                                          handler:^(__unused UIAlertAction *action) {
+                                            [weakSelf showStep093Menu];
+                                          }]];
+  [alert addAction:[UIAlertAction actionWithTitle:@"Close"
+                                            style:UIAlertActionStyleCancel
+                                          handler:nil]];
+  [self presentViewController:alert animated:YES completion:nil];
+}
+
+- (MLNFillStyleLayer *)step093FillLayer:(NSString *)identifier
+                                 source:(NSString *)sourceIdentifier
+                                  color:(UIColor *)color
+                                opacity:(CGFloat)opacity {
+  MLNSource *source = [self.mapView.style sourceWithIdentifier:sourceIdentifier];
+  MLNFillStyleLayer *layer = [[MLNFillStyleLayer alloc] initWithIdentifier:identifier
+                                                                    source:source];
+  layer.fillColor = [NSExpression expressionForConstantValue:color];
+  layer.fillOpacity = [NSExpression expressionForConstantValue:@(opacity)];
+  return layer;
+}
+
+- (MLNLineStyleLayer *)step093LineLayer:(NSString *)identifier
+                                 source:(NSString *)sourceIdentifier
+                                  color:(UIColor *)color
+                                  width:(CGFloat)width {
+  MLNSource *source = [self.mapView.style sourceWithIdentifier:sourceIdentifier];
+  MLNLineStyleLayer *layer = [[MLNLineStyleLayer alloc] initWithIdentifier:identifier
+                                                                    source:source];
+  layer.lineColor = [NSExpression expressionForConstantValue:color];
+  layer.lineWidth = [NSExpression expressionForConstantValue:@(width)];
+  layer.lineOpacity = [NSExpression expressionForConstantValue:@0.95];
+  return layer;
+}
+
 // Earthquake Heatmap
 
 - (void)addEarthquakeHeatmap {