Aseprite Pipeline

Screenshot

An animated 32×48 hero metasprite whose every byte of data is generated from a single Aseprite project — no hand-written frame tables, no hand-typed animation clips. This is the working reference for the two-tool sprite pipeline:

hero.aseprite ─┬─ res/hero.png  + hero.png.toml  → opensnes-sprite sheet → hero.pic/.pal + hero_meta.inc
               │                                    (tiles, palette, metasprite pointer table)
               └─ res/hero.json + hero.json.toml → opensnes-sprite anim  → hero_anim.h
                                                    (one AnimClip per Aseprite tag)

sheet owns the pixels and the metasprite geometry; anim owns the timeline (tags, per-frame durations, direction). They meet at the frame value: a clip's frame i selects hero_metasprites[i], resolved inline by animTickMeta() and drawn with oamDrawMetasprite().

The artist authored two tags in Aseprite — walk (forward loop) and wave (ping-pong) — with per-frame millisecond durations. opensnes-sprite anim converted those to ticks and folded the ping-pong into the frame order. Press A to toggle between the two generated clips.

SNES Concepts

• Metasprite composition from multiple OAM entries (oamDrawMetasprite)
• The anim.h player driving a metasprite via animTickMeta()
• Machine-generated metasprite table (opensnes-sprite sheet --metasprite) + animation clips (opensnes-sprite anim)
• OBJSEL size mode and OBJ VRAM base for 16×16 hardware sprites
• Sprite palette at CGRAM 128 (OBJ_CGRAM_BASE)

How to Build

cd examples/sprites/aseprite_pipeline && make

The build runs the full pipeline from the two settings files beside the assets (res/hero.png.toml, res/hero.json.toml): opensnes-sprite sheet and opensnes-sprite anim, then the generated assets_gen.asm links the tiles, then main.c compiles (it #includes both generated headers). No data.asm, no conversion rule in the Makefile (docs/tools/CONVENTIONS.md).

Modules Used

console, sprite, dma, text, text4bpp, background, input, anim

See Also

• tools/opensnes-sprite — sheets, metasprites and Aseprite clips (docs/tools/opensnes-sprite.md)
• examples/sprites/metasprite — hand-authored metasprite composition
• examples/sprites/animated_sprite — single-sprite frame animation