RenderEffect
A per-pixel effect an ImageLayer applies to its recording each time it draws it, set as its renderEffect.
The layer hands the op createOp makes a BufferedImage.TYPE_INT_ARGB_PRE copy of the recording, grown on each side by outsets of transparent pixels, and draws the image the op returns in place of the recording: one pixel of it per pixel of the recording, with its top-left corner outsets above and left of the recording's.
The pixels are premultiplied, so an op that mixes neighboring pixels, such as a blur, mixes in no color from transparent ones.
An effect is immutable, and equal to another only when both make the same op at every scale: a layer draws what it kept from an equal effect instead of applying this one again.
Inheritors
Functions
The op to apply to a recording of scale device pixels per user-space unit: its width in pixels over its width in user space, or for a recording aligned to a destination, the destination's scale.