Project history

Documentation index

This document consolidates the development milestones that were previously split across release pages, tags, handoff notes, and renderer experiments.

Initial port

The project began as an NES/FDS-focused Libretro frontend based on the hunterk Mesen2 prototype and updated to MesenCE 2.2.1. Early work established:

Frontend smoothness and audio transport

The frontend moved from fixed decoded-frame polling delays to event-driven synchronization. It added duplicate-frame capability handling, bounded preservation of partially accepted audio batches, and fast-forward backlog trimming.

Semantic HD-pack rules

Large HD packs gained pages, watches, palette sets, reusable rectangles, contexts, templates, routes, and replacements. These authoring constructs lower to the classic Mesen runtime rule model.

HD priority compositor

The lightweight compositor kept rendering local to the native candidates available at each location and attached synthetic additions to source provenance. It fixed multiple detached-piece and stale-cache problems without the major cost of a discarded full-scene compositor.

Gameplay parallax

Background wrapping and gameplay-based scrolling enabled seamless long-level parallax. A bulk strip compositor provided smooth HD-pixel motion for eligible layers with compatibility fallback.

Stable native metasprites

Renderer debugging established that native PPU priority cannot fully define ownership for enlarged artwork outside original opaque pixels. Stable primary-OAM identity fixed scanline ownership. Geometry-based 2x2/2x3 grouping made native metasprites atomic regardless of OAM permutation. Global temporal matching and immutable lifetime priority tokens removed whole-object flashing and midpoint priority reversals.

This work became the foundation of the 0.9.1 alpha line.

Version reset

The earlier public 1.x tags represented rapid experimental milestones rather than a finished stable API. The project reset to a pre-1.0 alpha line so future changes communicate maturity honestly: