projectRegionBetweenPlanes

function projectRegionBetweenPlanes(
  sourcePlaneDefinition: PlaneDefinition,
  targetPlaneDefinition: PlaneDefinition,
  region: PlaneRegion,
): PlaneRegion;

Each point is converted to a color on the source plane (axis channels from the point, other channels from the source plane's fixed values) and then projected onto the target plane's axes; the target plane's own fixed values are ignored. This keeps the same colors under a different axis range, orientation or channel order. Both steps clamp to the plane viewport, so points outside [0, 1] on the source plane are clamped first and colors outside the target ranges land on the target's edge. Paths keep their point count; nothing is resampled, so strongly non-linear mappings (for example between models) only bend the outline at its existing vertices.

Parameters

sourcePlaneDefinitionPlaneDefinition

Plane the region's points are expressed in.

targetPlaneDefinitionPlaneDefinition

Plane to express them in.

regionPlaneRegion

Region in source-plane normalized coordinates.

Returns

PlaneRegionThe region in target-plane normalized coordinates.

Example

import { projectRegionBetweenPlanes, type PlaneDefinition } from '@pbroom/color-kit/plane';

const full: PlaneDefinition = { model: 'oklch', fixed: { h: 250 } };
// Same plane zoomed to lightness 0.5–1.
const zoomed: PlaneDefinition = { model: 'oklch', x: { channel: 'l', range: [0.5, 1] }, fixed: { h: 250 } };
const line = { paths: [[{ x: 0.25, y: 0.5 }, { x: 0.75, y: 0.5 }, { x: 1, y: 0.5 }]] };

projectRegionBetweenPlanes(full, zoomed, line).paths[0];
// → [{ x: 0, y: 0.5 }, { x: 0.5, y: 0.5 }, { x: 1, y: 0.5 }] (l = 0.25 clamps to the edge)

See also

Also exported from

• @pbroom/color-kitthe same declaration, re-exported