This document defines frame time allocations for AstraWeave games targeting 60 FPS.
| Metric | Value | Notes |
|---|
| Target FPS | 60 | Standard for action games |
| Frame Budget | 16.67 ms | 1000ms ÷ 60 |
| Headroom Target | 20% | 3.33 ms reserved for spikes |
| Available Budget | 13.34 ms | 80% of frame |
| System | Budget (ms) | Percentage | Notes |
|---|
| Game Logic | 2.0 | 12% | ECS, AI, gameplay |
| Physics | 2.5 | 15% | Simulation, collision |
| Rendering | 6.0 | 36% | Draw calls, GPU sync |
| Audio | 0.5 | 3% | Spatial audio, mixing |
| Networking | 1.0 | 6% | Sync, prediction |
| UI | 0.5 | 3% | HUD, menus |
| I/O | 0.5 | 3% | Streaming, saves |
| Headroom | 3.67 | 22% | Spike absorption |
| Total | 16.67 | 100% | — |
Frame Budget: 16.67ms
├── Game Logic ████░░░░░░░░░░░░░░░░ 2.0ms (12%)
├── Physics █████░░░░░░░░░░░░░░░ 2.5ms (15%)
├── Rendering ████████████░░░░░░░░ 6.0ms (36%)
├── Audio █░░░░░░░░░░░░░░░░░░░ 0.5ms (3%)
├── Networking ██░░░░░░░░░░░░░░░░░░ 1.0ms (6%)
├── UI █░░░░░░░░░░░░░░░░░░░ 0.5ms (3%)
├── I/O █░░░░░░░░░░░░░░░░░░░ 0.5ms (3%)
└── Headroom ███████░░░░░░░░░░░░░ 3.67ms (22%)
| Component | Budget (µs) | Notes |
|---|
| ECS core (1k entities) | 85 | 0.51% of frame |
| AI updates (500 agents) | 471 | GOAP + arbiter |
| Gameplay systems | 500 | Combat, quests, dialogue |
| Script execution | 300 | Rhai scripts |
| Event processing | 200 | Input, triggers |
| Total | 1,556 | 22% headroom within budget |
| Entity Count | ECS Budget | AI Agents | Feasibility |
|---|
| 1,000 | 85 µs | 500 | ✅ Comfortable |
| 5,000 | 529 µs | 1,000 | ✅ Within budget |
| 10,000 | 1 ms | 2,000 | ⚠️ Near limit |
| 20,000+ | >2 ms | — | ❌ Consider 30 FPS |
| Component | Budget (µs) | Notes |
|---|
| Rigid body simulation | 500 | 100 bodies |
| Character controllers | 200 | Player + NPCs |
| Collision detection | 800 | Spatial hash accelerated |
| Raycasts | 300 | AI, weapons, cameras |
| Triggers/sensors | 200 | Zone detection |
| Total | 2,000 | 20% headroom |
With spatial hashing (99.96% check reduction):
| Objects | Naive | With Hash | Savings |
|---|
| 100 | 4,950 checks | 2 checks | 99.96% |
| 1,000 | 499,500 checks | ~20 checks | 99.996% |
| 10,000 | 49.9M checks | ~200 checks | 99.9996% |
| Stage | Budget (ms) | Notes |
|---|
| Culling | 0.5 | Frustum, occlusion |
| Shadow passes | 1.0 | CSM, spot shadows |
| G-Buffer | 1.5 | Deferred geometry |
| Lighting | 1.0 | Clustered, IBL |
| Post-processing | 1.0 | Bloom, SSAO, TAA |
| UI overlay | 0.5 | HUD, debug |
| GPU sync | 0.5 | Fence waiting |
| Total | 6.0 | — |
| Category | Calls | Notes |
|---|
| Opaque geometry | 500 | With instancing |
| Transparent | 100 | Sorted, no batching |
| Shadows | 200 | Per cascade |
| UI | 50 | Batched |
| Total | 850 | Target maximum |
| Component | Budget (µs) | Notes |
|---|
| Voice mixing | 200 | 4-bus mixer |
| Spatial positioning | 150 | 3D audio |
| DSP effects | 100 | Reverb, filters |
| Stream decode | 50 | Music, ambient |
| Total | 500 | — |
#![allow(unused)]
fn main() {
use std::time::Instant;
struct FrameBudget {
logic_budget: Duration,
physics_budget: Duration,
render_budget: Duration,
}
impl FrameBudget {
fn check(&self, phase: &str, elapsed: Duration, budget: Duration) {
if elapsed > budget {
warn!(
"{} exceeded budget: {:?} > {:?} ({}%)",
phase,
elapsed,
budget,
(elapsed.as_micros() * 100 / budget.as_micros())
);
}
}
}
}
#![allow(unused)]
fn main() {
#[cfg(feature = "profiling")]
{
astraweave_profiling::zone!("GameLogic");
// ... game logic ...
}
}
For complex simulations or lower-end hardware:
| Metric | Value |
|---|
| Frame Budget | 33.33 ms |
| Headroom | 6.67 ms (20%) |
| Available | 26.66 ms |
When to use 30 FPS:
- Open worlds with >20k entities
- Complex physics simulations
- Lower-end hardware targets
- Cinematic experiences
| Violation | Duration | Response |
|---|
| Minor | 1-2 frames | Log, continue |
| Moderate | 3-10 frames | Reduce quality |
| Severe | >10 frames | Emergency LOD |
#![allow(unused)]
fn main() {
// Reduce quality on budget overrun
if frame_time > Duration::from_millis(18) {
quality.reduce_shadow_resolution();
}
if frame_time > Duration::from_millis(20) {
quality.reduce_draw_distance();
}
if frame_time > Duration::from_millis(25) {
quality.disable_post_processing();
}
}