Skip to main content

Internal Renderer Properties

⚠️ Warning: Internal APIs

These properties are internal to the renderer implementation and may change in future versions. Use with caution and always check for existence before accessing.

renderer._allSkins​

Array of all skin objects managed by the renderer.

Access Pattern​

const renderer = util.runtime.renderer;
const skin = renderer._allSkins[skinId];

if (!skin) {
  console.warn('Skin not found');
  return;
}

Common Skin Properties​

All Skins:

  • size - [width, height] array with skin dimensions
  • _id - The skin's unique ID

SVG Skins Only:

  • _svgImageLoaded - Boolean indicating if SVG has finished loading
  • _svgImage - The underlying SVG image element

Example: Query Skin Dimensions​

getSkinWidth(skinId) {
  const renderer = this.runtime.renderer;
  const skin = renderer._allSkins[skinId];
  
  if (!skin || !skin.size) return 0;
  
  return Math.ceil(skin.size[0]);
}

renderer._allDrawables​

Array of all drawable objects in the scene.

Access Pattern​

const renderer = util.runtime.renderer;
const drawable = renderer._allDrawables[drawableId];

if (!drawable) {
  console.warn('Drawable not found');
  return;
}

Drawable Properties​

  • skin - Reference to the current skin object
  • _visible - Boolean visibility state
  • Other internal properties (position, scale, effects, etc.)

Example: Direct Skin Manipulation​

setSkin(drawableId, skinId) {
  const renderer = this.runtime.renderer;
  
  // Direct manipulation of drawable's skin
  // Warning: Bypasses normal Scratch costume system
  renderer._allDrawables[drawableId].skin = renderer._allSkins[skinId];
}

Best Practices​

1. Always Check Existence​

if (!renderer._allSkins || !renderer._allSkins[skinId]) {
  console.warn('Skin not found or renderer internals changed');
  return;
}

2. Provide Fallbacks​

const size = skin.size || [100, 100]; // Default if unavailable

3. Document Usage​

When using internal APIs:

  • Comment clearly that you're using internal APIs
  • Explain why they're necessary
  • Note potential breaking changes

4. Prefer Public APIs​

Check if public APIs can achieve the same result. Internal APIs should be a last resort.

Why Use Internal APIs?​

Sometimes internal APIs are necessary for:

  • Skin Dimensions - No public API to query skin size
  • Direct Manipulation - Bypassing normal costume system for custom skins
  • Advanced Features - Accessing properties not exposed publicly

Risks​

  • Breaking Changes - Internal APIs may change without notice
  • Undefined Behavior - Using internals incorrectly can cause crashes
  • Compatibility - May not work across different renderer versions