Advanced topics

Advanced covers cross-cutting behavior and production concerns: composition, resource governance, security, performance, migration, video, and audio. Full per-feature option matrices remain in Feature guides; exact public names/signatures belong in the API reference.

#Production/runtime guides

#Composition model

Simple imperative flows are typically:

1. createCanvas() → CanvasResults base raster.
2. createImage() / createText() / path2d.custom() / path2d.draw() → new PNG buffers.
3. save() for files, or toOutput() for explicit constructor-selected encoded output.

outPut() remains only as a deprecated compatibility alias for toOutput().

For declarative multi-layer stacks (charts, nested surfaces, one-shot PNG/GIF/video), use Scene overview with createScene, renderScene, renderSceneToGIF, and renderSceneToVideoFrames.

For reusable composition, use Composition hub: templates, named assets, built-in scene-layer components, plugins, and explicit $asset resolution rules.

#Composition · templates · assets · components

Template/component output is ordinary SceneLayer[]; final scene rendering remains subject to mandatory validation and resource limits.

#Engines you touch indirectly

These are current Node implementation dependencies. They do not imply the future Phase 15+ package architecture is already shipped.

#Performance intuition

• createImage() filters and transforms can be native/raster intensive; dimensions dominate memory/cost.
• pixels.getData() / pixels.manipulate() are appropriate for explicit pixel work but scale with touched pixels.
• batch() runs independent jobs with bounded concurrency; chain() runs sequentially and feeds output forward.
• scenes/templates can avoid awkward repeated imperative composition; nested surfaces composite directly rather than requiring a PNG encode/decode boundary at each nesting level.
• generated GIF AsyncIterable frames preserve producer backpressure rather than collecting all generated frames first.
• remote video is staged by streaming into isolated temporary files.

Use Performance & memory before increasing concurrency or resource ceilings.

#Video — editor pipelines

Start with Video (advanced) hub to choose videoPipeline() vs createVideo() vs Scene export.

FFmpeg/ffprobe are required only for video/FFmpeg functionality and run under the central process/network/temp/resource policy.

#Audio — procedural SFX

Start with Audio (advanced) hub.

Procedural audio is bounded by duration/sample-rate/channel/event/layer/partial and peak working-memory limits; see Runtime governance.

#Source-of-truth rule

Historical pages and old examples are not allowed to override current 6.0 runtime/export behavior. For the current contract use:

1. current package runtime/exports/declarations and packed consumer tests;
2. API reference;
3. current feature/advanced guides;
4. internals/changelog only as historical context.