feat(camera): v0.3.0 — add screen_to_world(sx, sy) unproject (P.3.6)

init.lua

@@ -1,7 +1,9 @@
 -- =====================================================================
--- lib-core.camera v0.2.0 — 2D Camera State + Free-Pan + Bounds-Clamping
+-- lib-core.camera v0.3.0 — 2D Camera State + Free-Pan + Bounds-Clamping + Screen-Unproject
 -- See: meta/docs/superpowers/specs/2026-05-13-p3-5-camera-free-pan-design.md
 --
+-- v0.3.0 additions (additiv über v0.2.0):
+--   - screen_to_world(sx, sy) — unproject screen-coord to world-coord
 -- v0.2.0 additions (additiv über v0.1.0):
 --   - Pan-API (keys / edge / drag, additiv, per-source toggle-bar)
 --   - Bounds-Clamping (always-on once set; clear_bounds to disable)
@@ -232,6 +234,21 @@ function M.update(dt)
     end
 end
 
+-- v0.3.0 NEW — Coordinate Unproject (Screen → World)
+
+function M.screen_to_world(sx, sy)
+    if type(sx) ~= "number" or type(sy) ~= "number" then
+        error("camera.screen_to_world: sx and sy must be numbers")
+    end
+    local w, h = engine.window.size()
+    -- Inverse of Raylib 2D camera transform (origin = center, no rotation):
+    --   screen.x = (world.x - target.x) * zoom + w/2
+    --   → world.x = (screen.x - w/2) / zoom + target.x
+    local wx = (sx - w / 2) / zoom_v + target_x
+    local wy = (sy - h / 2) / zoom_v + target_y
+    return wx, wy
+end
+
 -- DEPRECATED-MVP: forward-compat stubs (siehe Spec §7):
 -- DEPRECATED-MVP: function M.follow(entity)            -- lib-core.actor slice
 -- DEPRECATED-MVP: function M.lerp_to(target, dt)       -- smooth-follow slice

manifest.lib

@@ -1 +1 @@
-{"id":"lib-core.camera","version":"0.2.0","api_min":"0.1","deps":[{"id":"lib-core.input","version":"0.3.0"}]}
+{"id":"lib-core.camera","version":"0.3.0","api_min":"0.1","deps":[{"id":"lib-core.input","version":"0.3.0"}]}