In-engine profiler (CPU/GPU frame stats, Tracy integration)

Motivation

AAA studios live by profiler data. Without per-frame CPU/GPU stats available inside the editor and the running game, every optimisation step is blind guessing. Profiling must be a first-class citizen, not an afterthought.

Goal

Ship an integrated profiler that shows CPU frame breakdown, GPU timings, draw-call counts, memory, and entity/component stats — in both the Studio viewport and the built game — with an optional Tracy open-telemetry export for deep dives.

Tasks

In-process profiling API

• PROFILE_SCOPE(name) macro / Zig comptime helper that records begin/end timestamps on a per-thread ring buffer
• GPU timer queries (SDL3 GPU timestamp queries) for render passes and draw calls
• Stats counters: draw calls, triangles, material switches, texture binds, allocs/frame

Studio profiler panel

• Flame graph / timeline view of the last N frames (CPU + GPU lanes)
• Stats bar in the viewport HUD: FPS, frame ms, GPU ms, draw calls
• Memory profiler tab: heap breakdown by allocator/system
• Per-system update time breakdown (scene, physics, audio, render)

Built-game profiler

• Toggle via CLI flag or debug server command (#2 (closed)) — zero overhead when disabled
• Overlay HUD mode (FPS + stats, toggled at runtime via a key)
• Export frame data as JSON/CSV for CI regression detection

Tracy integration

• Conditional Tracy client linkage (-Dtracy=true build option)
• Map PROFILE_SCOPE and GPU queries to Tracy zones
• Document Tracy server setup + capturing a profile

Acceptance Criteria

• Studio shows a profiler panel with CPU/GPU flame graph for the last frame.
• Built game can display an overlay HUD and export frame data.
• Tracy integration works when opted in at build time.
• Profiler adds zero runtime cost when disabled.

Related

• #2 (closed) (Debug server exposes perf endpoints), #31 (closed) (Play Mode where profiler runs live), (built game infra).