kitepdf-core/io.github.yuroyami.kitepdf.core.render/KiteShading/FunctionBased

FunctionBased

class FunctionBased(val colorSpace: KiteColorSpace, val background: RgbColor?, val bbox: KiteRectangle?, val domain: DoubleArray, val matrix: KiteMatrix, function: KiteFunction) : KiteShading

Type 1: colour as a function of (x, y) over domain (x0 x1 y0 y1), mapped into user space by matrix. Rendered as a grid of coloured cells by paintComplexShading.

Constructors

FunctionBased

constructor(colorSpace: KiteColorSpace, background: RgbColor?, bbox: KiteRectangle?, domain: DoubleArray, matrix: KiteMatrix, function: KiteFunction)

Properties

background

open override val background: RgbColor?

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.

bbox

open override val bbox: KiteRectangle?

Optional clipping rectangle (/BBox) in shading-space.

colorSpace

open override val colorSpace: KiteColorSpace

The shading's colour space (DeviceGray / DeviceRGB / DeviceCMYK / Indexed).

domain

val domain: DoubleArray

x0, x1, y0, y1.

matrix

val matrix: KiteMatrix

Functions

colorAt

fun colorAt(x: Double, y: Double): RgbColor

sampleStops

fun KiteShading.sampleStops(count: Int = 256): GradientStops?

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).

spreadOver

fun KiteShading.spreadOver(spread: KiteGradientSpread, region: KiteRectangle): KiteShading

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.