move to directories. add examples

src/ecs.odin

@@ -0,0 +1,51 @@
+package shoal
+
+import "core:strings"
+import rl "vendor:raylib"
+
+STARTUP := 0
+UPDATE := 1
+DRAW := 2
+
+App :: struct {
+	startup_systems: [dynamic]proc(),
+	update_systems:  [dynamic]proc(),
+	draw_systems:    [dynamic]proc(),
+	plugins:         [dynamic]proc(app: ^App),
+	entities:        [dynamic]Entity,
+}
+
+add_system :: proc(app: ^App, schedule: int, system: proc()) {
+	switch schedule {
+	case STARTUP:
+		append(&app.startup_systems, system)
+	case UPDATE:
+		append(&app.update_systems, system)
+	case DRAW:
+		append(&app.draw_systems, system)
+	}
+}
+
+add_plugin :: proc(app: ^App, plugin: proc(app: ^App)) {
+	append(&app.plugins, plugin)
+}
+
+run :: proc(app: ^App, entity_limit: int = 1000) {
+	for p in app.plugins {
+		p(app)
+	}
+	for i in app.startup_systems {i()}
+
+	_, window := single(&Window)
+	rl.InitWindow(window.width, window.height, strings.clone_to_cstring(window.title))
+	defer rl.CloseWindow()
+
+	rl.SetTargetFPS(60)
+	for !rl.WindowShouldClose() {
+		rl.ClearBackground(window.background)
+		for i in app.update_systems {i()}
+		rl.BeginDrawing()
+		for i in app.draw_systems {i()}
+		rl.EndDrawing()
+	}
+}