From ec5c8277a02010867b07d7891dd51cdc8d3fc332 Mon Sep 17 00:00:00 2001
From: DualFroz <me@dualfroz.com>
Date: Tue, 25 Aug 2026 09:00:00 +0200
Subject: [PATCH] feat(light): add light-aware visibility

---
 src/light.lua | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)
 create mode 100644 src/light.lua

diff --git a/src/light.lua b/src/light.lua
new file mode 100644
index 0000000..a8a4a60
--- /dev/null
+++ b/src/light.lua
@@ -0,0 +1,25 @@
+-- Visibility with light. The player sees out to their carried light radius via
+-- shadowcasting; on top of that, any static emitter the player can already see
+-- casts its own pool of light, so a lit room reveals itself the moment the
+-- player glimpses its brazier. Darkness is simply a smaller player radius.
+
+local Fov = require("fov")
+
+local Light = {}
+
+function Light.compute(map, originX, originY, radius, lights)
+  local visible = Fov.compute(map, originX, originY, radius)
+  if lights then
+    for _, emitter in ipairs(lights) do
+      if visible[map:index(emitter.x, emitter.y)] then
+        local pool = Fov.compute(map, emitter.x, emitter.y, emitter.radius)
+        for idx in pairs(pool) do
+          visible[idx] = true
+        end
+      end
+    end
+  end
+  return visible
+end
+
+return Light