Cache clip defs on sprites to avoid per-frame map lookups.

Crowd stress (128 sprites) showed Clip_Def string map_get as the top engine cost; cache on set_sprite_clip and use it in update/draw.

engine/sprite.odin

@@ -8,6 +8,8 @@ Sprite :: struct {
 	data:      ^Character_Data,
 	position:  Vec2,
 	clip:      string,
+	clip_def:  Clip_Def, // shallow cache; frames alias Character_Data (do not mutate clips map after spawn)
+	has_clip:  bool,
 	frame:     int,
 	time:      f32,
 	flip_x:    bool,
@@ -24,9 +26,8 @@ spawn_sprite :: proc(
 		position = position,
 	}
 	set_sprite_clip(&sprite, clip)
-	if frame != 0 {
+	if frame != 0 && sprite.has_clip {
-		c, ok := character_clip(sprite.data, sprite.clip)
+		c := sprite.clip_def
-		if ok {
 		if frame < 0 {
 			sprite.frame = 0
 		} else if frame >= len(c.frames) {
@@ -35,16 +36,15 @@ spawn_sprite :: proc(
 			sprite.frame = frame
 		}
 	}
-	}
 	return sprite
 }
 
 update_sprite :: proc(sprite: ^Sprite, dt: f32) {
 	if sprite == nil || sprite.data == nil do return
 	if dt <= 0 do return
+	if !sprite.has_clip do return
 
-	clip, ok := character_clip(sprite.data, sprite.clip)
+	clip := sprite.clip_def
-	if !ok do return
 
 	frame_count := len(clip.frames)
 	if frame_count <= 0 do return
@@ -92,12 +92,13 @@ draw_sprite :: proc(app: ^App, sprite: ^Sprite) {
 	if len(app.draw_list) >= MAX_SPRITES {
 		return
 	}
-
+	if !sprite.has_clip do return
-	frame, ok := character_frame(sprite.data, sprite.clip, sprite.frame)
+	if sprite.frame < 0 || sprite.frame >= len(sprite.clip_def.frames) {
-	if !ok {
 		return
 	}
 
+	frame := sprite.clip_def.frames[sprite.frame]
+
 	src_w := f32(frame.source_size[0])
 	src_h := f32(frame.source_size[1])
 	if src_w <= 0 do src_w = f32(frame.rect[2])
@@ -148,12 +149,14 @@ draw_sprite :: proc(app: ^App, sprite: ^Sprite) {
 set_sprite_clip :: proc(sprite: ^Sprite, clip: string) {
 	if sprite == nil || sprite.data == nil do return
 
-	if sprite.clip == clip do return
+	if sprite.clip == clip && sprite.has_clip do return
 
-	_, ok := character_clip(sprite.data, clip)
+	def, ok := character_clip(sprite.data, clip)
 	if !ok do return
 
 	sprite.clip = clip
+	sprite.clip_def = def
+	sprite.has_clip = true
 	sprite.frame = 0
 	sprite.time = 0
 }

examples/crowd/main.odin

@@ -1,9 +1,12 @@
 package main
 
+import "core:fmt"
 import eng "pkg:engine"
 
-// Many sprites sharing one Character_Data (Flyweight) — good batching demo.
+// Stress the draw budget: one Character_Data, MAX_SPRITES instances.
-COUNT :: 24
+COUNT :: eng.MAX_SPRITES
+COLS :: 16
+FRAME_LOG_EVERY :: 60
 
 main :: proc() {
 	app: eng.App
@@ -16,25 +19,45 @@ main :: proc() {
 
 	sprites: [COUNT]eng.Sprite
 	for i in 0 ..< COUNT {
-		col := i % 8
+		col := i % COLS
-		row := i / 8
+		row := i / COLS
 		pos := eng.Vec2 {
-			f32(120 + col * 80),
+			f32(40 + col * 48),
-			f32(280 + row * 120),
+			f32(80 + row * 60),
 		}
 		clip := "idle" if (i % 2) == 0 else "walk"
 		sprites[i] = eng.spawn_sprite(&data, pos, clip, i % 5)
 	}
 
-	// Look at the middle of the grid
 	app.camera.position = {400, 400}
 
 	last := eng.now_seconds()
+	frame_i := 0
+	sum_ms: f64
+	peak_ms: f64
 
 	for eng.events() {
 		now := eng.now_seconds()
 		dt := f32(now - last)
 		last = now
+		frame_ms := f64(dt) * 1000.0
+		sum_ms += frame_ms
+		if frame_ms > peak_ms do peak_ms = frame_ms
+		frame_i += 1
+
+		if frame_i % FRAME_LOG_EVERY == 0 {
+			avg := sum_ms / f64(FRAME_LOG_EVERY)
+			fps := 1000.0 / avg if avg > 0 else 0
+			fmt.printfln(
+				"crowd frame: avg=%.2f ms (%.1f FPS) peak=%.2f ms over %d frames",
+				avg,
+				fps,
+				peak_ms,
+				FRAME_LOG_EVERY,
+			)
+			sum_ms = 0
+			peak_ms = 0
+		}
 
 		for &s in sprites {
 			eng.update_sprite(&s, dt)