Performance and Refactoring

Detailed implementation plans are consolidated in optimization-roadmap.md. This document retains the evaluation principles to avoid duplicating the todo and architecture documents.

Priorities

Priority	Direction	Main Benefit	Risk
High	Render targets and GPU resource lifecycles	Reduce black screens, stale textures, and context recreation issues	High
High	Video frame submission and target Layer compositing	Complete the video display pipeline	High
Medium	Flutter FFI buffer reuse	Reduce allocations and copies in the readback path	Medium
Medium	Font cache and prerendered metrics	Improve text layout and font-switching stability	Medium
Medium	TJS2 hot paths	Reduce CPU usage in script-intensive scenes	High
Low	Restore SIMD PS blending	Improve throughput for specific blending modes	High, requires per-pixel verification
Low	Reduce header dependencies	Shorten incremental compilation time	Medium

Evaluation Rules

• Measure first, then optimize; do not change hotspot code without baseline data.
• Any pixel, script, audio-video, save-data, or lifecycle optimization must retain the old path as a regression baseline.
• Make local, reversible changes first, then consider cross-module refactoring.
• Rendering and asynchronous code must cover creation, restart, background recovery, size changes, exceptions, and destruction paths.
• Use frame time, peak memory, power consumption, and compatibility results on target platforms as the final criteria; do not substitute a single host-machine result.