--- id: kw-layer name: layer category: scenes kind: keyword tokens: layer sig: layer Name { handlers } tip: A named group of handlers inside a scene; layers render in declaration order. order: 1 --- A `layer` groups handlers inside a scene, and declaration order is draw order: within a phase the active scene's layers run in the order they were written, so a `Hud` layer declared after a `World` layer paints its `Render` output on top. Layers are the natural unit for stacking a heads-up display over the play-field, or a menu over a paused world. A layer handler may use any phase except `Start` (boot-time setup belongs in the scene's `on enter`). Handlers that should run in every scene are declared outside any scene rather than in a layer. ```ludic program LayerExample { property Position { column: int = 0, row: int = 0 } model Player { Position } let score: int = 0 scene Overworld start { on enter { spawn Player { Position { column: 6, row: 6 } } } layer World { handler DrawWorld phase Render { Screen.clear(Color.MidnightBlue) for (current_position) in query [Position, {Player}] { Screen.fill_rectangle(x: current_position.column * 16, y: current_position.row * 16, width: 16, height: 16, color: Color.LimeGreen) } } } layer Hud { handler DrawScore phase Render { Screen.draw_text(x: 6, y: 4, text: "SCORE", color: Color.White, scale: 1) Screen.draw_number(x: 52, y: 4, value: score, color: Color.Gold, scale: 1) Screen.show() # the last layer to draw presents the frame } } } } ```