Class Camera

This implementation will automatically fit the children's bounds into the calculation. Each child's bounds is limited to its mask's bounds or filterArea, if any is applied.

const cacheParent = elem.enableTempParent();
elem.updateTransform();
elem.disableTempParent(cacheParent);

This method is expensive on containers with a large subtree (like the stage). This is because the bounds of a container depend on its children's bounds, which recursively causes all bounds in the subtree to be recalculated. The upside, however, is that calling getBounds once on a container will indeed update the bounds of all children (the whole subtree, in fact). This side effect should be exploited by using displayObject._bounds.getRectangle() when traversing through all the bounds in a scene graph. Otherwise, calling getBounds on each object in a subtree will cause the total cost to increase quadratically as its height increases.

The transforms of all objects in a container's subtree and of all ancestors are updated. The world bounds of all display objects in a container's subtree will also be recalculated.

The _bounds object stores the last calculation of the bounds. You can use to entirely skip bounds calculation if needed.

const lastCalculatedBounds = displayObject._bounds.getRectangle(optionalRect);

Do know that usage of getLocalBounds can corrupt the _bounds of children (the whole subtree, actually). This is a known issue that has not been solved. See [getLocalBounds]{@link PIXI.DisplayObject#getLocalBounds} for more details.

getBounds should be called with skipUpdate equal to true in a render() call. This is because the transforms are guaranteed to be update-to-date. In fact, recalculating inside a render() call may cause corruption in certain cases.

Calling getLocalBounds may invalidate the _bounds of the whole subtree below. If using it inside a render() call, it is advised to call getBounds() immediately after to recalculate the world bounds of the subtree.

The [_render]{@link PIXI.Container#_render} method is be overriden for rendering the contents of the container itself. This render method will invoke it, and also invoke the render methods of all children afterward.

If renderable or visible is false or if worldAlpha is not positive or if cullable is true and the bounds of this object are out of frame, this implementation will entirely skip rendering. See {@link PIXI.DisplayObject} for choosing between renderable or visible. Generally, setting alpha to zero is not recommended for purely skipping rendering.

When your scene becomes large (especially when it is larger than can be viewed in a single screen), it is advised to employ culling to automatically skip rendering objects outside of the current screen. See [cullable]{@link PIXI.DisplayObject#cullable} and [cullArea]{@link PIXI.DisplayObject#cullArea}. Other culling methods might be better suited for a large number static objects; see @pixi-essentials/cull and pixi-cull.

The [renderAdvanced]{@link PIXI.Container#renderAdvanced} method is internally used when when masking or filtering is applied on a container. This does, however, break batching and can affect performance when masking and filtering is applied extensively throughout the scene graph.