Module paint

Paint primitives: the “what do we fill a shape with” side of theming.

A Paint is either a flat Color, a LinearGradient or a RadialGradient. Gradients carry their colour stops, a direction (angle for linear, center+radius for radial) and the GradientSpace in which stops are interpolated. Sampling happens downstream in the renderer; these types are pure data and have no rendering logic of their own.

Stop positions

Stops are represented as fractions (0.0..=1.0 for the caller’s mental model) but the ColorStop::position field accepts values outside that range. This is intentional: design-tool exports often emit gradients whose stops fall outside [0, 1], meaning the visible region of the shape only covers a middle slice of the interpolation. The renderer is expected to extrapolate linearly, not clamp.

Colour space

Picking the right interpolation space matters for saturated gradients: interpolating #04D9FE → #8A38F5 in sRGB produces a muddy grey in the middle, while Oklab keeps the chroma. The space is resolved at theme-load time (stops converted once), not per pixel.

Structs

• ColorStop
  One stop of a gradient: a position along the gradient axis (for linear) or along the radius (for radial), plus the Color at that point.
• LinearGradient
  A straight gradient swept along a vector set by an angle.
• RadialGradient
  A gradient radiating from a centre point out to a radius.

Enums

• GradientSpace
  Colour space in which a gradient’s stops are interpolated.
• Paint
  How a shape is filled: a flat colour or one of the gradient variants.