add High Contrast filter for maps

lib/services/map_tile_cache_service.dart

@@ -12,12 +12,15 @@ enum MapRasterSourcePreset {
   osmAuto('osm_auto'),
   osmStandard('osm_standard'),
   osmDark('osm_dark'),
+  osmDarkHC('osm_darkHC'),
   stamenTerrain('stamen_terrain'),
   alidadeSmoothDark('alidade_smooth_dark'),
   outdoors('outdoors'),
   osmBright('osm_bright'),
   outdoorsDark('outdoors_dark'),
-  osmBrightDark('osm_bright_dark');
+  outdoorsDarkHC('outdoors_darkHC'),
+  osmBrightDark('osm_bright_dark'),
+  osmBrightDarkHC('osm_bright_darkHC');
 
   const MapRasterSourcePreset(this.id);
 
@@ -101,6 +104,12 @@ class MapRasterSourceCatalog {
     label: 'OpenStreetMap Dark',
     description: 'Standard OpenStreetMap tiles with an inverted dark filter',
   );
+  static const MapRasterSourceDefinition osmDarkHC = MapRasterSourceDefinition(
+    id: 'osm_darkHC',
+    label: 'OpenStreetMap Dark High Contrast',
+    description:
+        'Standard OpenStreetMap tiles with an inverted high contrast dark filter',
+  );
   static const MapRasterSourceDefinition stamenTerrain =
       MapRasterSourceDefinition(
         id: 'stamen_terrain',
@@ -139,6 +148,14 @@ class MapRasterSourceCatalog {
         isStadia: true,
         allowsBulkDownload: true,
       );
+  static const MapRasterSourceDefinition outdoorsDarkHC =
+      MapRasterSourceDefinition(
+        id: 'outdoors',
+        label: 'Outdoors Dark High Contrast',
+        description: 'High contrast dark version of the Outdoors map style',
+        isStadia: true,
+        allowsBulkDownload: true,
+      );
   static const MapRasterSourceDefinition osmBrightDark =
       MapRasterSourceDefinition(
         id: 'osm_bright',
@@ -147,6 +164,14 @@ class MapRasterSourceCatalog {
         isStadia: true,
         allowsBulkDownload: true,
       );
+  static const MapRasterSourceDefinition osmBrightDarkHC =
+      MapRasterSourceDefinition(
+        id: 'osm_bright',
+        label: 'OSM Bright Dark High Contrast',
+        description: 'High contrast dark version of the OSM Bright map style',
+        isStadia: true,
+        allowsBulkDownload: true,
+      );
 
   static MapRasterSourceDefinition fromPreset(MapRasterSourcePreset preset) {
     switch (preset) {
@@ -156,16 +181,22 @@ class MapRasterSourceCatalog {
         return osmStandard;
       case MapRasterSourcePreset.osmDark:
         return osmDark;
+      case MapRasterSourcePreset.osmDarkHC:
+        return osmDarkHC;
       case MapRasterSourcePreset.alidadeSmoothDark:
         return alidadeSmoothDark;
       case MapRasterSourcePreset.outdoors:
         return outdoors;
       case MapRasterSourcePreset.outdoorsDark:
         return outdoorsDark;
+      case MapRasterSourcePreset.outdoorsDarkHC:
+        return outdoorsDarkHC;
       case MapRasterSourcePreset.osmBright:
         return osmBright;
       case MapRasterSourcePreset.osmBrightDark:
         return osmBrightDark;
+      case MapRasterSourcePreset.osmBrightDarkHC:
+        return osmBrightDarkHC;
       case MapRasterSourcePreset.stamenTerrain:
         return stamenTerrain;
     }
@@ -335,8 +366,11 @@ class MapTileCacheService extends ChangeNotifier {
   ) {
     switch (MapRasterSourcePreset.fromId(settings.mapRasterSourceId)) {
       case MapRasterSourcePreset.osmDark:
+      case MapRasterSourcePreset.osmDarkHC:
       case MapRasterSourcePreset.outdoorsDark:
+      case MapRasterSourcePreset.outdoorsDarkHC:
       case MapRasterSourcePreset.osmBrightDark:
+      case MapRasterSourcePreset.osmBrightDarkHC:
         return true;
       case MapRasterSourcePreset.osmAuto:
         return brightness == Brightness.dark;
@@ -349,6 +383,25 @@ class MapTileCacheService extends ChangeNotifier {
     }
   }
 
+  static bool _isHighContrastDarkPreset(MapRasterSourcePreset preset) {
+    switch (preset) {
+      case MapRasterSourcePreset.osmDarkHC:
+      case MapRasterSourcePreset.outdoorsDarkHC:
+      case MapRasterSourcePreset.osmBrightDarkHC:
+        return true;
+      case MapRasterSourcePreset.osmAuto:
+      case MapRasterSourcePreset.osmStandard:
+      case MapRasterSourcePreset.osmDark:
+      case MapRasterSourcePreset.stamenTerrain:
+      case MapRasterSourcePreset.alidadeSmoothDark:
+      case MapRasterSourcePreset.outdoors:
+      case MapRasterSourcePreset.outdoorsDark:
+      case MapRasterSourcePreset.osmBright:
+      case MapRasterSourcePreset.osmBrightDark:
+        return false;
+    }
+  }
+
   static const ColorFilter _darkMapFilter = ColorFilter.matrix([
     -0.0850,
     -0.2861,
@@ -371,6 +424,28 @@ class MapTileCacheService extends ChangeNotifier {
     1,
     0,
   ]);
+  static const ColorFilter _darkHCMapFilter = ColorFilter.matrix([
+    0.7634200013,
+    -1.9008999332,
+    -0.1915199924,
+    0,
+    338.15,
+    -0.5665799987,
+    -0.5720999709,
+    -0.1915199924,
+    0,
+    338.15,
+    -0.5665799987,
+    -1.9008999332,
+    1.1384799335,
+    0,
+    338.15,
+    0,
+    0,
+    0,
+    1,
+    0,
+  ]);
 
   CacheManager get _concreteCacheManager => cacheManager as CacheManager;
 
@@ -393,7 +468,13 @@ class MapTileCacheService extends ChangeNotifier {
     );
 
     if (shouldApplyDarkFilter) {
-      layer = ColorFiltered(colorFilter: _darkMapFilter, child: layer);
+      final activePreset = MapRasterSourcePreset.fromId(
+        appSettingsService.settings.mapRasterSourceId,
+      );
+      final filter = _isHighContrastDarkPreset(activePreset)
+          ? _darkHCMapFilter
+          : _darkMapFilter;
+      layer = ColorFiltered(colorFilter: filter, child: layer);
     }
 
     if (opacity < 1) {