Restrict each drawable light to its lumens level

src/main/java/net/rptools/maptool/client/ui/zone/Illumination.java

@@ -173,6 +173,24 @@ public Optional<LumensLevel> getObscuredLumensLevel(int lumensStrength) {
     return Collections.unmodifiableList(this.obscuredLumensLevels);
   }
 
+  /**
+   * Look up a disjoint obscured lumens level based on the lumens strength.
+   *
+   * <p>This is useful for rendering individual lights, so that the light can be constrained to the
+   * area that is actually illuminated by the light and not by any stronger light.
+   *
+   * <p>See {@link #getDisjointObscuredLumensLevels()} for more information.
+   *
+   * @param lumensStrength The strength of lumens to find.
+   * @return The {#link LumensLevel} of strength {@code lumensStrength}. If no level exists for it,
+   *     an empty optional is returned.
+   */
+  public Optional<LumensLevel> getDisjointObscuredLumensLevel(int lumensStrength) {
+    return getDisjointObscuredLumensLevels().stream()
+        .filter(level -> level.lumensStrength() == lumensStrength)
+        .findFirst();
+  }
+
   /**
    * Get the disjoint obscured lumens levels.
    *

src/main/java/net/rptools/maptool/client/ui/zone/ZoneView.java

@@ -39,6 +39,7 @@
 import net.rptools.maptool.model.zones.TokensChanged;
 import net.rptools.maptool.model.zones.TokensRemoved;
 import net.rptools.maptool.model.zones.TopologyChanged;
+import net.rptools.maptool.model.zones.ZoneLightingChanged;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
@@ -724,6 +725,8 @@ public Collection<DrawableLight> getDrawableLights(PlayerView view) {
         drawableLights.computeIfAbsent(
             view,
             view2 -> {
+              final var lightingStyle = zone.getLightingStyle();
+
               final var illuminationKey = illuminationKeyFromView(view2);
               final var illuminationModel = getIlluminationModel(illuminationKey);
 
@@ -755,9 +758,16 @@ public Collection<DrawableLight> getDrawableLights(PlayerView view) {
                         // Make sure each drawable light is restricted to the area it covers,
                         // accounting for darkness effects.
                         final var obscuredArea = new Area(laud.litArea().area());
+
+                        final var lumensStrength = Math.abs(laud.litArea().lumens());
                         final var lumensLevel =
-                            illumination.getObscuredLumensLevel(Math.abs(laud.litArea().lumens()));
-                        // Should always be present based on construction, but just in case.
+                            switch (lightingStyle) {
+                              case ENVIRONMENTAL -> illumination.getObscuredLumensLevel(
+                                  lumensStrength);
+                              case OVERTOP -> illumination.getDisjointObscuredLumensLevel(
+                                  lumensStrength);
+                            };
+                        // Should always be present based on construction, but just in case...
                         if (lumensLevel.isEmpty()) {
                           return null;
                         }
@@ -794,14 +804,18 @@ public void flush() {
     exposedAreaMap.clear();
     visibleAreaMap.clear();
 
-    drawableLights.clear();
-    drawableAuras.clear();
+    flushLights();
   }
 
   public void flushFog() {
     exposedAreaMap.clear();
   }
 
+  private void flushLights() {
+    drawableLights.clear();
+    drawableAuras.clear();
+  }
+
   /**
    * Flush the ZoneView cache of the token. Remove token from {@link #tokenVisionCachePerView}, and
    * {@link #illuminationModels}. Can clear {@link #tokenVisionCachePerView}, {@link
@@ -860,6 +874,15 @@ private void onTopologyChanged(TopologyChanged event) {
     topologyTrees.clear();
   }
 
+  @Subscribe
+  private void onZoneLightingChanged(ZoneLightingChanged event) {
+    if (event.zone() != this.zone) {
+      return;
+    }
+
+    flushLights();
+  }
+
   private boolean flushExistingTokens(List<Token> tokens) {
     boolean tokenChangedTopology = false;
     for (Token token : tokens) {
@@ -896,8 +919,7 @@ private void onTokensRemoved(TokensRemoved event) {
     }
 
     if (anyLightingChanges) {
-      drawableLights.clear();
-      drawableAuras.clear();
+      flushLights();
     }
 
     if (event.tokens().stream().anyMatch(Token::hasAnyTopology)) {
@@ -963,8 +985,7 @@ private void updateLightSourcesFromTokens(Iterable<Token> tokens) {
     }
 
     if (anyLightingChanges) {
-      drawableLights.clear();
-      drawableAuras.clear();
+      flushLights();
     }
   }
 }

src/main/java/net/rptools/maptool/model/Zone.java

@@ -61,6 +61,7 @@
 import net.rptools.maptool.model.zones.TokensChanged;
 import net.rptools.maptool.model.zones.TokensRemoved;
 import net.rptools.maptool.model.zones.TopologyChanged;
+import net.rptools.maptool.model.zones.ZoneLightingChanged;
 import net.rptools.maptool.server.Mapper;
 import net.rptools.maptool.server.proto.DrawnElementListDto;
 import net.rptools.maptool.server.proto.TopologyTypeDto;
@@ -515,6 +516,7 @@ public LightingStyle getLightingStyle() {
 
   public void setLightingStyle(LightingStyle lightingStyle) {
     this.lightingStyle = lightingStyle;
+    new MapToolEventBus().getMainEventBus().post(new ZoneLightingChanged(this));
   }
 
   public TokenSelection getTokenSelection() {

src/main/java/net/rptools/maptool/model/zones/ZoneLightingChanged.java

@@ -0,0 +1,19 @@
+/*
+ * This software Copyright by the RPTools.net development team, and
+ * licensed under the Affero GPL Version 3 or, at your option, any later
+ * version.
+ *
+ * MapTool Source Code is distributed in the hope that it will be
+ * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public
+ * License * along with this source Code.  If not, please visit
+ * <http://www.gnu.org/licenses/> and specifically the Affero license
+ * text at <http://www.gnu.org/licenses/agpl.html>.
+ */
+package net.rptools.maptool.model.zones;
+
+import net.rptools.maptool.model.Zone;
+
+public record ZoneLightingChanged(Zone zone) {}