Unsupported
Shading type we don't render; sampleStops returns null, so nothing paints.
Properties
Optional /Background colour, used for regions outside the shading domain when Extend is false on the relevant side. Per spec the background is in colorSpace; we eager-convert to RGB.
Optional clipping rectangle (/BBox) in shading-space.
The shading's colour space (DeviceGray / DeviceRGB / DeviceCMYK / Indexed).
Functions
Sample a KiteShading.Axial or KiteShading.Radial at evenly-spaced stops between domain[0] and domain[1]. Returns parallel t and RGB arrays the backend uses to build a gradient brush. The default of 256 matches MuPDF, so a function with many narrow bands keeps them all (#153).
This axial or radial shading continued past its ends by spread, over a region whose bounds in shading space are region. The result is an ordinary shading that every canvas paints: its geometry grows to cover the region, and a stitching function (ISO 32000-1, 7.10.4) repeats or mirrors the colours once per period.