Gradient filling properties are encapsulated by a HIG_VECT_GRADIENT handle. This handle is attached to a HIG_VECT_FILLTYPE object.

There are two types of gradient fillings: linear and radial.

• Linear gradient is defined by its start and end points.
• Radial gradient is defined by a start point and an outer circle. Start point should be located inside the outer circle, but not necessarily in its center. Coordinates of the gradient can be absolute or relative (to the bounding rectangle of the entity that uses the gradient).

The color of the gradient is defined by an array of stops. A stop is a pair of offset and color. Stop offsets are relative to gradient coordinates: 0.0 corresponds to the start point; 1.0 corresponds to the end points, in case of a linear gradient, or to a point at the outer circle, in case of radial gradient. If first stop offset is greater than 0.0, or last stop offset is less than 1.0, the gradient is expanded, according to its Spread method. Gradient color is linearly interpolated between the stops.

Gradient filling can be transformed with an affine matrix.