change built-in component names

ui/shoal.odin

@@ -1,9 +1,31 @@
 package ui
 
+import ecs "../src"
 import ml "vendor:microui"
 
+// the microui context UIPlugin refreshes every frame, nil until the first
+// PRE_DRAW. use get_ctx() instead of touching it directly
 ui_ctx: ^ml.Context
 
+// wires the ui package into the app, in frame order:
+//
+//	STARTUP     init() bakes the microui atlas into a texture
+//	PRE_DRAW    begin() forwards raylib input, starts the frame, stashes ui_ctx
+//	POST_DRAW   the frame's temp arena is freed, then end() renders the ui
+//	DESTROY     destroy() unloads the atlas texture
+//
+// (systems within a schedule run in registration order, so POST_DRAW frees
+// the arena first and renders second)
+UIPlugin :: proc(app: ^ecs.App) {
+	ecs.add_system(app, ecs.STARTUP, proc() {init()})
+	ecs.add_system(app, ecs.POST_DRAW, proc() {free_all(context.temp_allocator)})
+	ecs.add_system(app, ecs.PRE_DRAW, proc() {ui_ctx = begin()})
+	ecs.add_system(app, ecs.POST_DRAW, proc() {end()})
+	ecs.add_system(app, ecs.DESTROY, proc() {destroy()})
+}
+
+// the microui context for this frame. pass it to every microui call. valid
+// from PRE_DRAW onwards (nil before the first frame)
 get_ctx :: proc() -> ^ml.Context {
 	return ui_ctx
 }