Custom paint

Draw your own triangles for a node.

import { Painter, TrianglesPaint } from "willow";

Painter

class Painter

The view onto the render pipeline passed to a node's custom-paint function. Only valid while the function runs: using a stored Painter later raises InvalidStateError.

Painter: properties

Member	Description
readonly node: Node	The node whose custom-paint function is running.

Painter: methods

Member	Description
worldTransform(): Array<float>	The node's world transform as six numbers [a, b, c, d, tx, ty]. A point (x, y) maps to (a * x + c * y + tx, b * x + d * y + ty). The camera is applied after painting.
isBuildingCache(): boolean	True when this paint pass is building a cached subtree (CacheAsTree): skip transient or animated content that should not be folded into the cache.
paintDefault(): void	Draws the node's normal content (sprite, mesh, text, particles) so custom geometry can be added alongside it. Containers draw nothing.
appendTriangles(triangles: TrianglesPaint): void	Draws one batch of triangles. Vertices are copied; the arrays may be reused after.

TrianglesPaint

class TrianglesPaint

One batch of textured triangles for Painter.appendTriangles. Vertex positions are in world space: write them through Painter.worldTransform().

TrianglesPaint: constructors

new TrianglesPaint(vertices: Float32Array | Array<float>, indices: Array<int>)

Creates a batch from flat vertex data (eight numbers per vertex: x, y, u, v, r, g, b, a, colour channels 0.0 to 1.0) and a triangle list (three vertex indices per triangle).

TrianglesPaint: properties

Member	Description
vertices: Float32Array | Array<float>	Flat vertex data, eight numbers per vertex in order: x, y, u, v, r, g, b, a.
indices: Array<int>	Triangle list: three vertex indices per triangle.
texture?: Texture | TextureRegion	Image sampled by the triangles; omit to draw vertex colours only.
blendMode?: string	Blend mode name such as "normal" or "add" (same names as Node.blendMode).
renderLayer: int	Render layer, 0 to 255. Defaults to 0.
globalOrder: int	Secondary draw-order key within the render layer. Defaults to 0.