Implement thoughtsense detection mode

packs/ancestryfeatures/empathic-sense.json

@@ -42,6 +42,12 @@
                 "selector": "perception",
                 "type": "circumstance",
                 "value": 2
+            },
+            {
+                "acuity": "imprecise",
+                "key": "Sense",
+                "range": 15,
+                "selector": "thoughtsense"
             }
         ],
         "traits": {

packs/pathfinder-monster-core/rhu-chalik.json

@@ -710,7 +710,7 @@
                 {
                     "acuity": "precise",
                     "range": 60,
-                    "type": "tremorsense"
+                    "type": "thoughtsense"
                 }
             ]
         },

src/module/canvas/perception/modes.ts

@@ -152,12 +152,60 @@ class DetectionModeTremorPF2e extends DetectionModeTremor {
     }
 }
 
+class ThoughtsDetectionMode extends DetectionMode {
+    constructor() {
+        super({
+            id: "senseThoughts",
+            label: "PF2E.Actor.Creature.Sense.Type.Thoughtsense",
+            type: DetectionMode.DETECTION_TYPES.OTHER,
+            angle: false,
+        });
+    }
+
+    static override getDetectionFilter(): OutlineOverlayFilter {
+        const filter = (this._detectionFilter ??= OutlineOverlayFilter.create({
+            wave: true,
+            knockout: false,
+            outlineColor: [0, 1, 0, 1],
+        }));
+        filter.thickness = 1;
+        return filter;
+    }
+
+    protected override _canDetect(visionSource: PointVisionSourcePF2e, target: PlaceableObject): boolean {
+        // Not if the target isn't a token
+        if (!(target instanceof TokenPF2e)) return false;
+        const token: TokenPF2e = target;
+        if (!token.actor) return false;
+
+        // Not if the token is GM-hidden
+        if (token.document.hidden) return false;
+
+        // Detection only works on creatures
+        if (!token.actor.isOfType("creature")) return false;
+
+        // Detection cails on mindless creatures
+        if (token.actor.system.traits.value.includes("mindless")) return false;
+
+        // Detection fails if target is immune to mental
+        if (token.actor.attributes.immunities.some((i) => i.type === "mental")) return false;
+
+        return super._canDetect(visionSource, target);
+    }
+}
+
+declare namespace ThoughtsDetectionMode {
+    // eslint-disable-next-line no-var
+    var _detectionFilter: OutlineOverlayFilter | undefined;
+}
+
 function setPerceptionModes(): void {
     CONFIG.Canvas.visionModes.darkvision = darkvision;
     CONFIG.Canvas.detectionModes.basicSight = new VisionDetectionMode();
     CONFIG.Canvas.detectionModes.lightPerception = new LightPerceptionMode();
     CONFIG.Canvas.detectionModes.hearing = new HearingDetectionMode();
     CONFIG.Canvas.detectionModes.feelTremor = new DetectionModeTremorPF2e();
+    CONFIG.Canvas.detectionModes.senseThoughts = new ThoughtsDetectionMode();
 }
 
 export { setPerceptionModes };

src/module/scene/helpers.ts

@@ -97,6 +97,11 @@ function computeSightAndDetectionForRBV(token: TokenDocumentPF2e | PrototypeToke
         const range = scene?.flags.pf2e.hearingRange ?? null;
         token.detectionModes.push({ id: "hearing", enabled: true, range });
     }
+
+    const thoughtsense = actor.perception.senses.get("thoughtsense");
+    if (thoughtsense && thoughtsense.acuity !== "vague") {
+        token.detectionModes.push({ id: "senseThoughts", enabled: true, range: thoughtsense.range });
+    }
 }
 
 /** Returns true if this token has the default actor image or the default image for its actor type */