BlendMode class final

The blend mode a PaintLayer composites with — the plan's own five and no others.

A value class rather than an enum. tool/structure.dart's own rule treats an enum in a published package as either a closed external format (glTF's alpha modes, its wrap modes) or machinery with a reviewed exemption; this is neither — it is a fixed algorithmic set the same way LightingModel is a fixed set of shaders, and that row's own answer is the shape used here: a final class with named const instances, the blend formula itself carried as a field rather than read off a switch.

Properties

hashCode → int

The hash code for this object.

no setter, inherited

name → String

Shown in a status line or a test failure; not read by anything that changes behavior on it.

final

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

blendChannel(double top, double bottom) → double

This mode's own color math, top blended over bottom, both 0..1 — the part that differs between modes. Alpha itself is composited the same way regardless of mode; see PaintStack._over.

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

toString() → String

A string representation of this object.

override

Operators

operator ==(Object other) → bool

The equality operator.

inherited

Constants

add → const BlendMode

top + bottom, clamped to 1, per channel.

multiply → const BlendMode

top * bottom, per channel.

normal → const BlendMode

Plain alpha compositing: this layer's own color, mixed in by its own alpha over what is beneath it.

overlay → const BlendMode

bottom < 0.5 ? 2*top*bottom : 1 - 2*(1-top)*(1-bottom), per channel — multiply where the base is dark, screen where it is light.

screen → const BlendMode

1 - (1-top)*(1-bottom), per channel.

values → const List<BlendMode>

Every mode this class defines, for a picker to offer.